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What is Hardfacing Welding? – The Extensive FAQ Guide

The process of hardfacing welding has been sought after by many fabrication businesses. But what’s the mysterious success that lies beyond it?

In this complete guide about hardfacing welding, you’ll know and learn everything about it.

Not only will you have the best idea about hard surfacing in welding; you’ll also learn other things that can help you with your business, too!

What is Hardfacing or Hard Surfacing in Welding?

In the simplest terms, hardfacing is the process of depositing hard materials on a surface.

What is Hardfacing
The edges of the bucket are hardfaced to prevent excessive wear because they’re the most used

The goal is to allow a part or a component not to succumb to excessive wear; whether it’s corrosion, abrasion, friction, etc.

Different Hardfacing Welding Electrodes

If you were to perform hard surfacing, you can choose from three (3) categories of electrodes. They are:

DIfferent Hardfacing Electrodes
This image displays the results of using different hardfacing welding electrodes

  • Cobalt base electrodes
  • Iron base electrodes
  • Nickel base electrodes

Whatever electrode you choose, it’ll undergo alloying with other elements for hardfacing.

Can Hardfacing Welding be Done With MIG Wires?

Yes, you can use Metal Inert Gas (MIG) wires for your hardfacing procedure.

Hardfacing using MIG Wires
The welder is using MIG wires to prepare the workpiece for MIG hardfacing

In fact, the best MIG wires that experts recommend are: ER70S-6 and ER70S-3. But, your options aren’t just limited to that; you can choose other types and kinds of MIG wires, too!

The point is that you can consider MIG wires to be an electrode that you can utilize for hardfacing.

The video below explains more about how you can perform hardfacing welding using MIG wires.

What Do the Numbers on Hardfacing Welding Rod Mean?

If you’ve been wondering about the meaning of the numbers on welding rods, you’re not alone.

Numbers on Hardfacing Welding Rods
Different welding electrodes with different numbers, meaning different properties

A lot of people aren’t aware of what they are – but they’re actually not something you need to stress on!

These numbers are codes that you can use to identify the specific welding rod.

To start off, there are 4-digit and 5-digit numbers. In a 4-digit electrode number, the first two (2) indicate the tensile strength that the electrode can produce; it’s the first three (3) figures for 5-digit numbers.

The next number, the fourth, and the fifth (for 5-digit numbers), indicate the position of how you should use it.

The number one (1) denotes that it can be used in all positions; two (2) is something you can only use for horizontal and flat welds, etc.

Lastly, the fourth digit (or the 5th in a 5-digit number), tells you about the current welding (DC, AC, or even both), as well as the type of coating that it has.

Ideally, the numbers on a welding electrode helps you understand and identify that particular electrode.

What are Hardfacing Welding Machines?

These are machines that you can use to perform the hardfacing or the hard surfacing you need.

Hardfacing Machines
Different hardfacing welding machines Waldun is offering

You have the option to choose from a wide variety of hardfacing welders; there are:

  • Pipe hardfacing machines and equipment
  • One-head and two-head hardfacing machines
  • Robotic and automatic hardfacing machines
  • Valve hardfacing equipment
  • And others!

Because hard surfacing is a process you can accomplish through different techniques, you can use a lot of machines and equipment for it!

Can Hardfacing be Done With Oxyfuel?

It’s a type of welding process that utilizes oxygen combined with fuel gases for welding.

Hardfacing With Oxyfuel
Process of welding using oxyfuel, which means it’s applicable to hard surfacing

Since it’s one of the most well known and the most prominent welding strategies, you can use it for hard surfacing.

Akin to how you do MIG, SMAW, and PAW hardfacing, you perform oxyfuel welding using a welding torch too!

Here’s a quick clip of how you can use oxyfuel for hard surfacing.

What Materials Can Undergo Hard Surface Welding?

The most common types of base metals or materials that can experience hardfacing include:

What Materials can Undergo Hardfacing
Welding chuck clutching on an alloy while being hardfaced

  • Manganese steels
  • Cast irons and steels
  • Copper-based alloys
  • Nickel-based alloys
  • Stainless steels

As you noticed, these are materials used by many industrial businesses and companies.

What Welding Techniques Can You Use for Hardfacing Welding?

You can actually perform hard surfacing through various welding methods.

What Welding Techniques for Hard Surfacing Welding
Pipe being hardfaced using traditional Gas Metal Arc Welding (GMAW)

The most common methods you can perform to accomplish it include:

  • Gas Metal Arc Welding (GMAW)
  • Submerged Arc Welding (SAW)
  • Shielded Metal Arc Welding (SMAW)
  • Oxyfuel Welding
  • Plasma Transferred Arc Welding (PTA)
  • Thermal Spraying
  • And Others!

The method you want can’t be just handpicked randomly.

As a matter of fact, the process you’ll have to go with will depend on many things, such as the material you’ll apply over a surface, the type of attachment you want for it, and so on.

Is Hard Surfacing the Same with Hardfacing?

Hardfacing and hard surfacing welding are two (2) similar terms.

Both are known to be processes you can utilize to deposit a new material over a surface. You can think of it as hardfacing being the shorter term for hard surfacing.

Hardfacing Welding vs. Clad Welding

A lot of people know hardfacing in welding to be the same as cladding. However, they’re actually two (2) different processes.

Cladding using Laser
Pipe being cladded with another type of harder material

Cladding or clad welding is a welding overlay process that would yield a new surface. It’s the process of “cladding” or integrating another material on top of an existing one.

Usually, in cladding, you’d use a different material to be cladded to the surface of a workpiece.

Hardfacing or hard surface welding is a process you use to renew or rehabilitate a surface. Unlike cladding, you’ll want a material with almost the same type or the same properties as the workpiece.

That’s how the two processes are different; they’re the same in a sense, but they yield separate results.

How are Cladding and Hard Surface Welding Similar?

Now that you know how they differ, it is also important to know how they became two (2) processes that are similar.

We can summarize this lot by pointing out the following factors:

  • You can achieve both processes via the following:
    • Flux-cored arc welding (FCAW)
    • Plasma transferred arc (PTA) welding
    • Laser deposition
    • Thermal spraying
  • Used by many companies and businesses in various sectors
  • They have the same end-goal or vision, to protect the part or component or to prolong its lifespan
  • Both can use a wide range of welding electrodes

What are the Advantages of Hard Surfacing Welding?

Fundamentally, hard surfacing is done because of its benefits and advantages.

Advantages of Hard Surface Welding
The hardfaced edge of the bucket remains completely intact

The most common of these advantages include, but are not limited to:

Prolong the Life of Parts and Components

The primary benefit that hardfacing has is that it can help prolong and lengthen the life of parts. Whether the part is new or worn out, it can give this benefit or advantage.

Eliminate the Need to Replace Parts

If your parts don’t wear out fast, then you immediately eliminate the need to replace them.

Hard surface welding can get you the parts you need stronger, tougher, and more durable.

Increase Productivity and Efficiency

With parts and components good as new, you can be assured that your productivity and efficiency will be increased.

You don’t have to worry or stress about acquiring or sourcing out for parts. Instead, you can focus on your business and your operations.

Save up Costs and Expenses

If we summarize up every advantage it can give us, it’ll come down to you saving money.

With fewer parts needing replacement, less components to purchase, and less work needed done – it all translates to you saving up on extra costs and expenses.

Those are some of the most common benefits you can get from hardfacing welding.

Thee’s nothing spectacular about it; it wouldn’t increase your productivity or give you profits all of a sudden. It is, in fact, a slow but steady addition that you can treat as a big investment.

Hardfacing Welding Rod Types

In hardfacing welding, you don’t have to worry too much on the type of welding rods you’ll use.

Hardfacing Welding Rod Types
A few of the welding rods you can use for hard surfacing

You can choose from the wide variety of options you can utilize. You can use electrodes that have nickel as its base, iron as its base, and cobalt as its base.

Industries That Need to Use Hardfacing Welding

Whether you’re in the construction sector, the industrial sector, fabrication sector, or any other sector you can think of, hardfacing will probably be something you’ll need.

Industries That Need Hardfacing
The mining industry needs hardfacing to prolong the life of their machines

A lot of businesses require hardfacing because of the benefits it give. People think that it has something to do with design, but there’s actually more of it than that.

Some of the industries that find hardfacing useful and effective include:

  • Coal and Mining Industry
  • Power & Generation Industry
  • Metal and Metalworking Industry
  • Shipyard and Shipbuilding Industry
  • Marine and Maritime Industry

There are other industries that find hard surfacing effective.

Oftentimes, those businesses undergo the usual wear and tear of their machines and equipment.

What Applications Can You Use Hard Surfacing For?

You can use hardfacing for a lot of things. Among the most sought after is its ability to prolong the life of the parts of your machines or equipment.

Apart from that, you can also choose hard surfacing for:

  • Increasing the resistance of your base or parent metals
  • Restoring the surface of parts or components that are worn out
  • Improving or developing the physical traits of parts; and
  • Many more!

How Do I Get Rid of Old Hardfacing?

There is a myriad of ways on how you can remove or get rid of old hardfacing. However, the most common and the fastest way is through the ARCAIR system.

ARCAIR, short for Air-Carbon-Arc, is a welding process where the metal is cut and melted. This procedure utilizes a carbon arc and the heat from that arc is what does the job.

More often than not, the molten part is removed and eradicated using high-pressurized air.

This is the fastest and the most reasonable way to remove or get rid of old hardfacing.

What is Hardfacing?

In the world of metalworking, you would almost always encounter or hear hardfacing. Many people have the slightest idea on what it is, while there are others that don’t! In today’s guide, we will be focusing on discussing everything you need to know about hardfacing. At the end of this guide, you will definitely be able to wrap your head around it! Let alone, be a master of what it is!

Defining What Hardfacing Is

In simple terms, hard surfacing or “hardfacing,” is a metalworking procedure where you deposit tougher and harder material to a surface of a base metal. Defining What Hardfacing Is An example of a hardfaced excavator bucket The primary purposes of hardfacing are for the general improvement of the base metal. You can perform hardfacing if:

  • You want to prolong the lifespan of your parts and/or components
  • Your parts are already worn-out, to restore them
  • You’re looking to improve the performance of whatever part you have
  • You want to apply a wear-resistant material to your surface

Imagine this: a metal part of your equipment and you use it 6 to 8 hours on a daily basis. Do you think that part will be perfect all-year round? No, right? What Is Hardfacing

A perfect example of what hardfacing is and what it does to parts and components This is where hard surfacing comes in. Hard surfacing, more commonly known and referred to as hardfacing, is a process of applying wear-resistant material onto a surface via welding. The primary purpose of hardfacing is to extend and lengthen the life of a part. Looking back at our example, if the metal part of your equipment has hardfacing, then the part “itself” wouldn’t be damaged yet because the hardfacing would be what’s going to interact during business processes. We here at WALDUN are considered as the best and the most trusted hardfacing products manufacturer. We’re able to produce and manufacture materials for railroads, earthmoving, mining, dredging, farming, recycling, cement, and other industries that usually undergo extreme wear.

What Can You Hardface?

Hardfacing can be categorized into three (3) different applications: hardfacing or welding overlay, rebuilding or buildup, and a combination of the two. What Can You Hardface You can hardface many parts and components that usually undergo abrasion Obviously, extending a part’s life isn’t its only purpose. Hardfacing also is used if you’re looking to recondition or rehabilitate parts and components, if you want to restore the dimensions of your machines/equipment, etc. More often than not, low-alloyed and carbon steels are the base metals you can hardface. Here’s a quick list of the base metals and materials:

  • Copper-Based Alloys
  • Cast Irons
  • Stainless Steels
  • Carbon and Alloy Steels
  • Nickel-Based Alloys
  • Manganese Steels

Why are they the most common metals that are hardfaced, you may ask? – Because they are easily magnetic. Furthermore, you can easily distinguish them from a non-magnetic metal, austenitic manganese steel – among others. The purpose of being able to understand and distinguish them is because the pre and post-heat temperatures need to be determined; they’ll be critical to the hardfacing procedure. For you to understand better, Manganese steel really doesn’t require preheat treatment, while railing steel contains higher carbon and would require preheating of about 315 to 370 degrees Celsius (600 to 700 degrees Fahrenheit).

What Welding Processes Can You Use to Apply Hardfacing?

Here’s a quick list of the most prominent and the most famous welding process that you can use for a hardfacing procedure: What Welding Processes Can You Use To Apply Hardfacing In hardfacing, a lot of welding processes can be used

  • Plasma Transferred Arc (PTA) Welding
  • Laser Welding, Spray Fuse Welding, and Thermal Spraying
  • Oxy-Fuel Welding (OFW) or Oxyacetylene Welding
  • Gas Tungsten Arc Welding (GTAW or TIG Welding)
  • Submerged Arc Welding (SAW)
  • Shielded Metal Arc Welding (SMAW)
  • Gas Metal Arc Welding (GMAW or MIG) with Shielded Wire
  • Flux Cored Arc Welding (FCAW) with an Open-Arc or Gas-Shielded Hardfacing Wire

Currently, the procedures that are deemed to be the most effective and the most efficient are those that are semi-automatic and automatic welding processes. However, you can still freely choose and select a specific type of welding procedure for your hardfacing application depending on other factors, not just the process.

What Factors Should You Consider in Choosing a Welding Process?

But out of all the different factors and considerations in choosing welding procedures, how would you choose what you’ll use and utilize? NOTE: The process is one, if not the most influential factor for the result of the weld or the hardfacing. Here are a couple of factors you can consider:

  • Skill of the operator or the welder
  • Thickness of what you’re going to deposit
  • Deposition rate
  • Welding consumable size
  • Welding position to be used
  • Hardfacing consumable availability
  • Location of welding (indoor or outdoor)
  • Size of the component
  • Area of the part or component to be hardfaced
  • The finish you want to achieve
  • Machining requirements
  • Pre and post welding requirements
  • Preparation of the part or component

These are the factors that you can consider before you choose a welding procedure. So, before you decide on which specific welding process you want to perform, you need to consider and to check on all of these factors. You might be tagged along with all advantages and benefits, and you might tend to forget about other drawbacks as well.

What are the Most Economical Welding Processes?

While the economical factor of welding processes are based on many factors, the most influential one is the deposition rate. What Are The Most Economical Welding Processes Oxy-fuel welding is among the most economical welding procedures, but it’s not the best So, which ones can you consider as the most practical in terms of this factor? Here’s a quick list of a welding process or procedure along with its deposition rate:

  • Oxy-Fuel Welding (OFW) – 5 to 10 lbs per hour
  • Gas Tungsten Arc Welding (GTAW) – 3 to 5 lbs per hour
  • Flux-Cored Arc Welding (FCAW) – 8 to 25 lbs per hour
  • Submerged Arc Welding (SAW) – 8 to 25 lbs per hour
  • Shielded Metal Arc Welding (SMAW) – 3 to 5 lbs per hour
  • Gas Metal Arc Welding (GMAW) – 5 to 12 lbs per hour

Therefore, we can say that the most economical and the most practical deposition rate would be either the FCAW or the SAW.

Are There Different Types of Wear?

Discussing wear is too vague – because of the fact that it’s an all-encompassing term, there could be a lot of meaning out of it. Are There Different Types Of Wear Adhesive wear – one of the most common types and classifications of wear As a matter of fact, there are a couple of types and classifications of wear, they include:

  • Corrosion – 5 percent
  • Heat – 5 percent
  • Metallic or Adhesive Wear (Metal to Metal) – 15%
  • Impact – 20%
  • Abrasion – 40 to 50%
  • Other Types of Wear – 5 percent

When you come to think of it, different parts and components of machines and equipment don’t fail only on a single type of wear; they’re worn out when combinations of different types and classifications of wear are involved. To give you an example, teeth of a mining bucket are subject to impact and abrasion, since they’re used roughly. The classification of wear is a combination of abrasion and impact – it could also involve other types and kinds of wear.

What are the Most Common Types of Wear?

Apart from these different wear classifications, there are types of wear that are the most common, they include: What Are The Most Common Types Of Wear Corrosion is one of the most common types of wear and is encountered in a lot of sectors

Metal-to-Metal or Adhesive Wear

This type of wear occurs and happens when two (2) or more metallic surfaces slide and move against each other. It’s a classification of wear that happens and occurs under pressure, which then uses frictional heat to create a microwelding condition.

Corrosion (Corrosive Wear)

Corrosive wear is the type of wear also known to as chemical wear or oxidation. It’s usually caused by electrochemical and chemical reactions between both the environment and the surface. The damage from corrosion is from the synergistic attack of wear.

Abrasive Wear

This type of wear is when an abrasive material slides across a metal service. It can be anything from soil, coal, sand, glass, grains, and other minerals that are coarse and harsh in nature. Therefore, this type of wear only occurs when grainy materials scratch onto a metallic surface.

Impact Wear

Impact wear is a type of wear that occurs when a particular object is hit by another object with force, impact, and percussion. This type of wear happens because of repetitive exposure to contact that is dynamic.

Are There Different Categories of Hardfacing Alloys to Know Which Specific Alloy to Use?

Yes, you can categorize and separate hardfacing iron-based alloys into four (4) different main categories, they are:

Are There Different Hardfacing Alloys

WALDUN’s two-head hardfacing machine, capable of working on larger workpieces and parts Austenitic Austenitic alloys are groups of alloys that are work-hardening manganese stainless and steels. Generally speaking, though, they’re hardened only at the succession of the weld metal worked under repeated impact. In their true form, they’re soft and their malleable. Due to this, they’re known to have an excellent level of impact properties that also have moderate abrasion resistance. Should you be not aware, austenitic manganese steel is usually found in heavy earthmoving and the structural industries. Common applications include shovel teeth, crushers, excavators, railroad tracks, and the like.

Martensitic

Part of the martensitic hardfacing alloys includes all steels that have traits of being hardened. Usually, the alloys under the martensitic group have Rockwell hardness levels that range between 20 and 65 HRC. Although close to steel, they are different and they too harden when they’re cooled. Martensitic alloys are the best for abrasive wear, as well as metal-to-metal. In addition to that, they also perform a great deal of impact. Martensitic alloys that are at 50 HRC and above are the best for abrasion resistance. However, those that are below 45 HRC are for restoration and for build-up before hardfacing.

Metal Carbide in Hard Martensitic Matrix

These are martensitic alloys that have hardnesses ranging from 45 to 60 HRC. They’re tool steel that contain additives from titanium, molybdenum, niobium, and vanadium. If you’re able to properly apply it, you can be free from any stress cracks that are normal in this category of matrix.

Metal Carbide (Soft Austenitic Matrix)

Since they’re categorized with the “softer” austenitic matrix, you can expect hardnesses of these alloys within 40 to 65 HRC. These alloys have huge amounts of metal carbides in the softer matrix. Moreover, you can expect that they’re good for abrasion applications that are severe. It is also worth noting that these alloys that have large amounts of carbon and chromium are closer to either white or cast iron.

Is Cracking on Hardfacing Alloys Normal?

Cracking is normal, but it depends on the hardfacing alloy you’re using. Is Cracking Normal Cracking is normal, but it depends on the hardfacing alloy In the case of chromium carbide alloys, when they’re cooled to moderate and cold temperatures, they check-crack. On the other hand, alloys that are a part of the martensitic and austenitic families don’t.

What is Check-Cracking?

Is it similar to the normal cracking that we experience? Well, in all technicality, checking, or check-cracking, is the cracking that happens to the families of chromium carbide. You can easily identify them as cracks that run through the length of the bead. More often than not, they run between 8 mm or 3/8 inches to 50 mm or 2 inches. Check-cracking is the result of the high stress that’s induced by the weld metal contraction during the cooling stage. More often than not, check cracks appear through the weld bead’s thickness and stop at the base metal – if they’re not brittle. There also are cases where the base metal is brittle or hard, and in that scenario, you must choose a buffer layer of a tougher and a softer weld metal. In choosing the most effective for the buffer deposit, the best and the most ideal choice would be to select from the austenitic family.

What is Chromium Carbide Hardfacing?

You’d already have an idea on what it is – from its term alone. What Is Chromium Carbide Hardfacing An image of chromium carbide being prepared for integration It’s the procedure of hardfacing using chromium carbide alloys to parts and materials. Chromium carbide are iron-based alloys that have high levels of chromium and carbon (chromium > 15%; and carbon > 3%). Due to this chemistry, they’re able to form hard carbides that are capable of resisting highly abrasive environments. Frequently, chromium carbide hardfaced deposits check-crack; they do about every ½ inches. What this does is it helps relieve the stress from the welding procedure. Furthermore, they look better and more desirable in applications that need good slip materials because of their low-friction coefficient. In general, though, the level of abrasion resistance rises when the levels of chromium and carbon increase, too. However, carbon is sought and is known to be the most influential to the abrasion resistance. Apart from those two (2), there are other elements that are able to form other borides and carbides that assist in the increase of wear resistance in environments and temperatures with high applications.

Definition of Complex Carbides

Complex carbides are linked and connected to chromium carbide deposits that contain added vanadium, molybdenum, tungsten, as well as columbium. These elements that are added either form their own carbides or combine their carbides with the chromium carbides they have to add to the abrasion resistance of the carbides. Complex carbides can contain one element, two elements, three elements – even all of the elements. The applications of these complex carbides are for severe, as well as high abrasion and heat situations.

What are Martensite Carbides?

Martensite or martensitic carbides are carbides that have a high number of packed carbides that are usually:

  • Vanadium
  • Titanium
  • Niobium

Martensite carbides are the perfect choice for applications that need deposits that are free from cracks, and also those that have the best levels of wear traits. Furthermore, they’re perfect and ideal for these situations because weld deposits usually reveal similar characteristics of wear resistance that are expected from chromium carbide hardfacing products. Because of the fact that these alloys are far from cracking, they’re easier to apply and to deposit when it comes to reapplication.

What is an MIG Carbide?

It’s a type where the tungsten carbide particles are sent to PS98’s molten weld puddle directly from a hopper. After the weld bead cools, the weld deposit would have huge amounts of tungsten carbide particles that are attached in a tool steel matrix that is within the range of 55 to 60 HRC. Because of the hardness, these carbides are able to protect loader buckets, hammers, bulldozer and grader blades, and other impact and abrasive-prone parts and components.

What are Hardfacing Patterns?

As we try to remember, the goal of hardfacing is to protect the surface of the part or component from all the different types of wear present. What Are Hardfacing Patterns

An example of a hardfacing pattern for an excavator bucket That’s why if you are working in an environment with sand or dirt, the hardface you should apply must be weld beads that are spaced between 6.4 mm and 38 mm apart. In addition to that, they also must be perpendicular to the flow of the abrasives. On the other hand, if you are working in an environment with ore, slag, or rocky earth, the hardface must be weld bead ridges that are parallel or going with the flow of the materials. What these patterns do is they protect the metallic surface against abrasion by not trapping the material such as dirt, dust, rocks, or soil. If you are to work on clay content or soil, though, you would need a hardfacing pattern that would trap the soil onto the surface. Then, it would need to form a trapped soil layer, which will not only trap soil, but also keep it protected underneath.

Can You Use Hardness Values to Predict the Abrasion Resistant of an Alloy?

Contrary to popular belief, hardness values aren’t the ones responsible for the abrasion resistance of a particular alloy. For example, a chromium carbide alloy and a martensitic alloy can have the same hardness. In this case, let’s say it’s 60 HRC. While they have the same hardness level, they perform differently when they’re (1) exposed to high heat, (2) placed under the same abrasive conditions, and (3) when you use and slide them across soil and rocks. In this regard, chromium carbide alloys are better and more abrasion resistant compared to a martensitic alloy. However, you’ll be able to count that idea in if you are going to predict and anticipate the wear that alloys can have if they’re within the same family. For example, a chromium carbide alloy that has a hardness level of 50 HRC will definitely perform better and will be more abrasion resistant than a chromium carbide alloy that has a hardness level of 40 HRC. To cut it simply, the microstructure of the alloy needs to be considered; and to find that out, it’s best to contact and to inquire to your manufacturer about it.

How is Wear Measured?

As we know, hardness isn’t the only thing that makes a metal “tough” and “durable.” Apart form hardness, there are a couple of factors that allows wear to be measured. In fact, it will depend on the classification of wear that is involved. For instance, in abrasive wear, the ASTM Intl. G65 Dry Sand Rubber Wheel Test is the test used to measure how much abrasive a part can get.

What Gas Do You Use in GMAW Hardfacing?

Because this is a more crucial welding process, argon mixtures with a bit of oxygen and/or carbon dioxide and pure argon are the best gases you can use so you arrive at the best results. However, you’re not just limited to that. In fact, you can also make use of pure carbon dioxide.

What is a Globular Transfer or a Ball Transfer? Why is It Important?

A ball or a globular transfer utilizes gravity to transport large balls of molten electrodes from across the welding arc. It’s important because this procedure of transferring molten metal drops is smooth. Furthermore, you can find it at the best levels whenever you are going to fuse materials that need a good level of penetration.

Do You Need to Preheat Parts Before Hardfacing?

As we mentioned above, preheating a particular part or component would depend on what it is. Generally, though, all parts that are to be welded needs to be at least at a room temperature to avoid warping. The temperature needed for preheating will depend and be based on the base metal’s chemistry, as well as the workpiece you’ll work on. If you’re not sure of whether or not preheating is required, talk to your manufacturer about it and ask if preheating is still needed to start and initiate the work.

When Do You Use Cobalt Hardfacing Alloys?

Cobalt alloys have a lot of carbides on its belt. In addition to that, they’re also excellent when it comes to corrosion resistance, thanks to their good magnetic properties. Therefore, it’s ideal that you use them in applications that have high and severe temperatures and oxidation instances. The hardness deposition rates they have range between 25 HRC and 55 HRC; they also have work-hardening alloys.

When Do You Use Nickel Hardfacing Alloys?

On the other hand, it is best and ideal to utilize nickel hardfacing alloys in highly-corrosive atmospheres and environments. In addition to that, if you are going to work on peculiarly elevated temperatures, utilizing nickel hardfacing alloys would be the best thing to do. Nickel hardfacing alloys also have properties that allow them to resist friction, as well as adhesion.

Why Is There a Limit of About Three (3) Layers in Some Hardfacing Products?

While hardfacing doesn’t necessarily have any type of limits, there are some prodcuts that are just limited to about three (3) to five (5) layers. Why Is There A Limit Of Layers There are certain materials that should follow a limit when it comes to hardfacing Take chromium carbide for example. Chromium carbide, as a general rule, have certain limitations on the layers you can apply. Because of its brittle nature, many layers can lead to an orchestra of check-cracking. For you to know what the best and the most recommended number of layer is, ask your manufacturer for it. They’ll know the exact applications for it and they’ll be able to tell you the max for a hardfacing alloy.

What is a Buffer Alloy or a Build-Up?

These are alloys that are the same as the base or the parent metal when it comes to strength and hardness. More often than not, they have two (2) primary uses: You apply them to parts and components that are severely worn out to bring the dimensions and the figure back; and you can use them as a buffer for following layers to have a more and a better wear-resistant hardfacing deposition. Should there be cracks on your workpiece, you can always utilize a manganese product to stop the check-cracks from penetrating through the parent metal. NOTE: You should always put in mind that a mild steel electrode is never useful for a buffer layer or as a build-up alloy. Why? – Because mild steel electrodes do not have enough strength and durability to be able to support hardfacing. If you try using it, it will immediately and easily collapse under the hardfaced layer, causing it to fail and to exhibit damage.

Can You Hardface Cast Iron?

As part of the base metals and materials that can be hardfaced, yes, you can absolutely perform hardfacing of cast iron. However, you have to consider preheating the base metal first as well as some interpass temperatures. Nickel-iron products, as well as Nickel products are the best for the rebuilding of cast iron. Why? – Because the carbon content of cast iron wouldn’t be affected and altered – they’ll remain ductile. While you’ll find these questions the most asked questions about hardfacing, you shouldn’t just bank on it for all the information you need. Depending on the manufacturer you’ll trust, you can ask and inquire to them about all the other hardfacing procedures and rules you need to know. Here with us at WALDUN, we are equipped with the best men and the best experts when it comes to hardfacing. We have a knowledge-base or a hub of information that you can utilize for you and your business! Reach out to us and get the best hardfacing solutions you can get!

Hard Facing Welding Rod in Hardfacing

A welding rod is an electrode; and what this means is that it’s what you deposit to the surface of your base metal.

Hardfacing Welding Rod In Hardfacing

Hardfacing electrodes or welding rods Without a hardfacing welding rod, you wouldn’t be able to apply or deposit a tougher, stronger, and a more durable material. You can choose from a wide variety of hardfacing welding rods available in the market; it’s not just limited to one (1) kind.

What are the Advantages of Hardfacing?

Why should you perform hardfacing? Does it give you any benefit or advantage at all? What Are The Advantages Of Hardfacing A damaged chute because it doesn’t have hardfacing We’ve gathered some of the most sought after advantages you can have in performing hardfacing:

Decreased Downtime Instances

Adding up an extra layer of protection to your parts and components can help it become durable. Thus, reducing the instances of breakage, damage, and downtime. This is one of the many reasons why a lot of people go with hardfacing.

Longer Lasting and More Durable Parts and Components

What’s the most common reason why some base metals get worn out? – Because of having little-to-no protection. With hardfacing, you not only get extra protection; your parts can also become abrasion and corrosion-resistant, too, making them last longer and become more durable.

Reduced Costs

A significant reduction in cost is one of the most notable benefits of hardfacing. Because of the fact that it allows base metals to be stronger, tougher, and more durable, you will have fewer needs to repair and replace them – giving you relevant reduction in cost.

Better Part Performance

Imagine a chute without any type of hardfacing – do you think they’ll function properly? They absolutely will, for a time. However, if you continue to use it without any sort of protection, it’ll be damaged – and not for long, it can break. If it has a hardfacing coating, you can expect it not to wear down easily. Making it function better and more efficiently.

Reduced Storage Space Needs

Hardfacing protects your parts and components to be worn out; reducing the need for you to store spare and back-up resources. In asking what hardfacing is, these benefits can clearly give you the answers you’re looking for. To let you know, though, these aren’t the only advantages you can get with hardfacing, there are a lot more! But, the endpoint of these benefits and advantages would fall on you gaining more savings and reducing costs!

Thermal Spraying vs. Hardfacing: How Do They Differ?

Hardfacing and thermal spraying aren’t two (2) fruits from a different tree. Thermal Spraying Vs. Hardfacing Thermal spraying procedure in hardfacing a round workpiece As a matter of fact, thermal spraying is one of the processes used in hardfacing. Hardfacing is the more general term of material deposition over a base metal. Thermal spraying is a kind of hardfacing technique where droplets of semi-molten material are deposited, creating the coating or the hardface.

The Most Common Materials Used in Hardfacing

Now that we’re aware of the fact that hardfacing utilizes tougher and stronger material, what are the most common ones you can use for it? Most Comon Materials Used In Hardfacin Nickel-based alloys – one of the most common materials used in hardfacing The most common materials you can apply in a hardfacing procedure includes:

  • Nickel-based alloys
  • Chromium carbide alloys
  • Stellite
  • Cobalt-based alloys
  • NOREM Alloy

What is NOREM?

If you got confused with what NOREM is, don’t worry – you’re not alone. NOREM is known as a hardfacing material developed by the Electric Power Research Institute or the EPRI. It’s a cobalt-type hardfacing alloy that is wear resistant and is known to have replaced other cobalt-based. You can find NOREM in nuclear and chemical industries, and sectors of those sorts. As of today, there are a total of eight (8) variants of NOREM, namely:

  • 02
  • 02A
  • 03A
  • 03B
  • 04A
  • 04B
  • 05A
  • 05B

Methods Used to Deposit Hardfacing

There are quite a few techniques and processes you can perform to deposit hardfacing. Methods Used To Deposit Hardfacing

A construction machinery part hardfaced using laser cladding Some of the most common welding processes include:

  • Shielded Metal Arc Welding (SMAW)
  • Oxy-Fuel Welding (OFW)
  • Electro Slag Welding (ESW)
  • Submerged Arc Welding (SAW)
  • Plasma Transferred Arc Welding (PTAW) or Powder Plasma Welding
  • Gas Metal Arc Welding (GMAW)

Apart from welding procedures, you can also perform other techniques, which are:

  • Laser Cladding
  • Thermal Spraying
  • Cold Polymer Compounds
  • Hard Paint

The goal is to be able to deposit the material onto the surface, so any of these processes is good.

Do You Need to Heat Workpieces Before Hardfacing Them?

One of the general rules of hardfacing is that all workpieces must be brought to room temp. Do You Need To Heat Workpieces Before Hardfacing Them

Semi-molten material being used for hardfacing However, it’s not something you should abide by 100% of the time. In fact, some metals and alloys are required to be preheated before working on them; this will depend on the chemical composition of that alloy or metal.

Is Hardfacing Limited to Just One (1) Layer?

No, hardfacing can even go up to two (2) to five (5) layers, depending on the product. Is Hardfacing Limited To One Layer Multiple-layer hardfacing on a heavy-earth moving equipment Products that are a part of metal carbide families are just limited to just 2 to 3 layers. On the other hand, though, you can apply an unlimited amount of layers if you use austenitic and martensitic products.

Machines Used for Hardfacing 

Hardfacing isn’t a procedure you can do without any machines or equipment. Machines Used For Hardfacing

One-head hardfacing machine offered by Waldun In fact, choosing the right machinery will get the job done easier, faster, and more conveniently. The machines you’ll choose will depend on the results you want to achieve. Nevertheless, here are some examples of machines you can use for hardfacing:

One and Two-Head Hardfacing Machine 

It’s a type of machine where a welding head is present. The one-head contains one (1) welding head, while the two-head has two (2). Furthermore, it has a bed where the workpiece shall be loaded. It’s a good type of machine because it reduces workforce while ensuring the quality of the hardfacing procedure.

PTA or Plasma Transferred Arc Welding Machine 

PTA welding equipment is a sort of thermal process where AR material is applied and deposited to surfaces. Compared to others, they’re considered to be flexible and versatile machines.

Pipe Hardfacing Equipment

Working on pipes is not the same as working on a flat-shaped workpiece. Pipes and tubes need a specific type of machine in order to get the work done – that’s what pipe hardfacing machines are for. It utilizes automatic arc welding and is multifunctional. These aren’t the only machines you can use to perform hardfacing – there are others, in fact, a lot more! These are just equipment widely and most commonly used.

Can You Perform Hardfacing on Excavator Buckets?

Hardfacing has a significant impact in both heavy-earth and construction industries. An Excavator Bucket Hardfaced With Durable And Tough Material

An excavator bucket hardfaced with durable and tough material Therefore, performing hardfacing on excavator buckets can yield a lot of positive results, in terms of strength, durability, efficiency, and effectiveness.

Hardfacing Electrode Price

Without an electrode, you wouldn’t be able to perform hardfacing. So, the million-dollar question is, how much do they cost? To be frank, hardfacing electrodes and rods differ in prices. More so, their prices would depend on a lot of factors, including:

  • The element of the hardfacing electrode
  • Tensile strength and hardness
  • Composition

What Types of Wear Can Hardfacing Put an End To?

Depending on your industry and the use of your parts and components, hardfacing can stop many different types of wear. What Types Of Wear Can Hardfacing Put An End To Damaged pipe because it lacks hardfacing The most common ones include abrasion, corrosion, impact, friction, and heat. By performing hardfacing, you wouldn’t have to worry about these types of wear!

Is Cracking on Hardfaced Alloys Normal?

Cracking is a sign of inconsistency and breakage – therefore, it’s not normal if you look at it generally.

Is Cracking On Hardfaced Alloys Normal

Cracking on hardfaced alloy However, there are types and instances where cracking is part of its natural physicality. For instance, chromium carbide alloys show check cracks whenever they’re cooled down to median temperatures; and in this case, it’s normal. But, you always need to see cracking as a type of hint going to damage or breakage.

Can You Perform Hardfacing on New Parts?

Absolutely! As a matter of fact, most companies make this choice in order for the parts to have a longer lifespan, and to be able to function better and properly. The increased wear resistance that it has offers a domino effect on all other benefits. All of the advantages and benefits of hardfacing would also apply if you perform hardfacing on newly manufactured and produced parts and components.

What is Hardfacing?

In the world of metalworking, you would almost always encounter or hear hardfacing. Many people have the slightest idea on what it is, while there are others that don’t!

In today’s guide, we will be focusing on discussing everything you need to know about hardfacing. At the end of this guide, you will definitely be able to wrap your head around it! Let alone, be a master of what it is!

Defining What Hardfacing Is

In simple terms, hard surfacing or “hardfacing,” is a metalworking procedure where you deposit tougher and harder material to a surface of a base metal. Defining What Hardfacing Is An example of a hardfaced excavator bucket The primary purposes of hardfacing are for the general improvement of the base metal. You can perform hardfacing if:

  • You want to prolong the lifespan of your parts and/or components
  • Your parts are already worn-out, to restore them
  • You’re looking to improve the performance of whatever part you have
  • You want to apply a wear-resistant material to your surface

Imagine this: a metal part of your equipment and you use it 6 to 8 hours on a daily basis. Do you think that part will be perfect all-year round? No, right?

What Is Hardfacing
A perfect example of what hardfacing is and what it does to parts and components

This is where hard surfacing comes in. Hard surfacing, more commonly known and referred to as hardfacing, is a process of applying wear-resistant material onto a surface via welding.

The primary purpose of hardfacing is to extend and lengthen the life of a part. Looking back at our example, if the metal part of your equipment has hardfacing, then the part “itself” wouldn’t be damaged yet because the hardfacing would be what’s going to interact during business processes.

We here at WALDUN are considered as the best and the most trusted hardfacing products manufacturer.

We’re able to produce and manufacture materials for railroads, earthmoving, mining, dredging, farming, recycling, cement, and other industries that usually undergo extreme wear.

What Can You Hardface?

Hardfacing can be categorized into three (3) different applications: hardfacing or welding overlay, rebuilding or buildup, and a combination of the two.

What Can You Hardface
You can hardface many parts and components that usually undergo abrasion

Obviously, extending a part’s life isn’t its only purpose. Hardfacing also is used if you’re looking to recondition or rehabilitate parts and components, if you want to restore the dimensions of your machines/equipment, etc.

More often than not, low-alloyed and carbon steels are the base metals you can hardface. Here’s a quick list of the base metals and materials:

  • Copper-Based Alloys
  • Cast Irons
  • Stainless Steels
  • Carbon and Alloy Steels
  • Nickel-Based Alloys
  • Manganese Steels

Why are they the most common metals that are hardfaced, you may ask? – Because they are easily magnetic. Furthermore, you can easily distinguish them from a non-magnetic metal, austenitic manganese steel – among others.

The purpose of being able to understand and distinguish them is because the pre and post-heat temperatures need to be determined; they’ll be critical to the hardfacing procedure.

For you to understand better, Manganese steel really doesn’t require preheat treatment, while railing steel contains higher carbon and would require preheating of about 315 to 370 degrees Celsius (600 to 700 degrees Fahrenheit).

What Welding Processes Can You Use to Apply Hardfacing?

Here’s a quick list of the most prominent and the most famous welding process that you can use for a hardfacing procedure:

What Welding Processes Can You Use To Apply Hardfacing
In hardfacing, a lot of welding processes can be used

  • Plasma Transferred Arc (PTA) Welding
  • Laser Welding, Spray Fuse Welding, and Thermal Spraying
  • Oxy-Fuel Welding (OFW) or Oxyacetylene Welding
  • Gas Tungsten Arc Welding (GTAW or TIG Welding)
  • Submerged Arc Welding (SAW)
  • Shielded Metal Arc Welding (SMAW)
  • Gas Metal Arc Welding (GMAW or MIG) with Shielded Wire
  • Flux Cored Arc Welding (FCAW) with an Open-Arc or Gas-Shielded Hardfacing Wire

Currently, the procedures that are deemed to be the most effective and the most efficient are those that are semi-automatic and automatic welding processes.

However, you can still freely choose and select a specific type of welding procedure for your hardfacing application depending on other factors, not just the process.

What Factors Should You Consider in Choosing a Welding Process?

But out of all the different factors and considerations in choosing welding procedures, how would you choose what you’ll use and utilize?

NOTE: The process is one, if not the most influential factor for the result of the weld or the hardfacing.

Here are a couple of factors you can consider:

  • Skill of the operator or the welder
  • Thickness of what you’re going to deposit
  • Deposition rate
  • Welding consumable size
  • Welding position to be used
  • Hardfacing consumable availability
  • Location of welding (indoor or outdoor)
  • Size of the component
  • Area of the part or component to be hardfaced
  • The finish you want to achieve
  • Machining requirements
  • Pre and post welding requirements
  • Preparation of the part or component

These are the factors that you can consider before you choose a welding procedure.

So, before you decide on which specific welding process you want to perform, you need to consider and to check on all of these factors.

You might be tagged along with all advantages and benefits, and you might tend to forget about other drawbacks as well.

What are the Most Economical Welding Processes?

While the economical factor of welding processes are based on many factors, the most influential one is the deposition rate.

What Are The Most Economical Welding Processes
Oxy-fuel welding is among the most economical welding procedures, but it’s not the best

So, which ones can you consider as the most practical in terms of this factor?

Here’s a quick list of a welding process or procedure along with its deposition rate:

  • Oxy-Fuel Welding (OFW) – 5 to 10 lbs per hour
  • Gas Tungsten Arc Welding (GTAW) – 3 to 5 lbs per hour
  • Flux-Cored Arc Welding (FCAW) – 8 to 25 lbs per hour
  • Submerged Arc Welding (SAW) – 8 to 25 lbs per hour
  • Shielded Metal Arc Welding (SMAW) – 3 to 5 lbs per hour
  • Gas Metal Arc Welding (GMAW) – 5 to 12 lbs per hour

Therefore, we can say that the most economical and the most practical deposition rate would be either the FCAW or the SAW.

Are There Different Types of Wear?

Discussing wear is too vague – because of the fact that it’s an all-encompassing term, there could be a lot of meaning out of it.

Are There Different Types Of Wear
Adhesive wear – one of the most common types and classifications of wear

As a matter of fact, there are a couple of types and classifications of wear, they include:

  • Corrosion – 5 percent
  • Heat – 5 percent
  • Metallic or Adhesive Wear (Metal to Metal) – 15%
  • Impact – 20%
  • Abrasion – 40 to 50%
  • Other Types of Wear – 5 percent

When you come to think of it, different parts and components of machines and equipment don’t fail only on a single type of wear; they’re worn out when combinations of different types and classifications of wear are involved.

To give you an example, teeth of a mining bucket are subject to impact and abrasion, since they’re used roughly. The classification of wear is a combination of abrasion and impact – it could also involve other types and kinds of wear.

What are the Most Common Types of Wear?

Apart from these different wear classifications, there are types of wear that are the most common, they include:

What Are The Most Common Types Of Wear
Corrosion is one of the most common types of wear and is encountered in a lot of sectors

Metal-to-Metal or Adhesive Wear

This type of wear occurs and happens when two (2) or more metallic surfaces slide and move against each other.

It’s a classification of wear that happens and occurs under pressure, which then uses frictional heat to create a microwelding condition.

Corrosion (Corrosive Wear)

Corrosive wear is the type of wear also known to as chemical wear or oxidation.

It’s usually caused by electrochemical and chemical reactions between both the environment and the surface. The damage from corrosion is from the synergistic attack of wear.

Abrasive Wear

This type of wear is when an abrasive material slides across a metal service. It can be anything from soil, coal, sand, glass, grains, and other minerals that are coarse and harsh in nature.

Therefore, this type of wear only occurs when grainy materials scratch onto a metallic surface.

Impact Wear

Impact wear is a type of wear that occurs when a particular object is hit by another object with force, impact, and percussion.

This type of wear happens because of repetitive exposure to contact that is dynamic.

Are There Different Categories of Hardfacing Alloys to Know Which Specific Alloy to Use?

Yes, you can categorize and separate hardfacing iron-based alloys into four (4) different main categories, they are:

Are There Different Hardfacing Alloys
WALDUN’s two-head hardfacing machine, capable of working on larger workpieces and parts

Austenitic

Austenitic alloys are groups of alloys that are work-hardening manganese stainless and steels. Generally speaking, though, they’re hardened only at the succession of the weld metal worked under repeated impact.

In their true form, they’re soft and their malleable.

Due to this, they’re known to have an excellent level of impact properties that also have moderate abrasion resistance.

Should you be not aware, austenitic manganese steel is usually found in heavy earthmoving and the structural industries. Common applications include shovel teeth, crushers, excavators, railroad tracks, and the like.

Martensitic

Part of the martensitic hardfacing alloys includes all steels that have traits of being hardened.

Usually, the alloys under the martensitic group have Rockwell hardness levels that range between 20 and 65 HRC. Although close to steel, they are different and they too harden when they’re cooled.

Martensitic alloys are the best for abrasive wear, as well as metal-to-metal. In addition to that, they also perform a great deal of impact.

Martensitic alloys that are at 50 HRC and above are the best for abrasion resistance. However, those that are below 45 HRC are for restoration and for build-up before hardfacing.

Metal Carbide in Hard Martensitic Matrix

These are martensitic alloys that have hardnesses ranging from 45 to 60 HRC. They’re tool steel that contain additives from titanium, molybdenum, niobium, and vanadium.

If you’re able to properly apply it, you can be free from any stress cracks that are normal in this category of matrix.

Metal Carbide (Soft Austenitic Matrix)

Since they’re categorized with the “softer” austenitic matrix, you can expect hardnesses of these alloys within 40 to 65 HRC.

These alloys have huge amounts of metal carbides in the softer matrix. Moreover, you can expect that they’re good for abrasion applications that are severe.

It is also worth noting that these alloys that have large amounts of carbon and chromium are closer to either white or cast iron.

Is Cracking on Hardfacing Alloys Normal?

Cracking is normal, but it depends on the hardfacing alloy you’re using.

Is Cracking Normal
Cracking is normal, but it depends on the hardfacing alloy

In the case of chromium carbide alloys, when they’re cooled to moderate and cold temperatures, they check-crack. On the other hand, alloys that are a part of the martensitic and austenitic families don’t.

What is Check-Cracking?

Is it similar to the normal cracking that we experience? Well, in all technicality, checking, or check-cracking, is the cracking that happens to the families of chromium carbide.

You can easily identify them as cracks that run through the length of the bead.

More often than not, they run between 8 mm or 3/8 inches to 50 mm or 2 inches. Check-cracking is the result of the high stress that’s induced by the weld metal contraction during the cooling stage.

More often than not, check cracks appear through the weld bead’s thickness and stop at the base metal – if they’re not brittle.

There also are cases where the base metal is brittle or hard, and in that scenario, you must choose a buffer layer of a tougher and a softer weld metal.

In choosing the most effective for the buffer deposit, the best and the most ideal choice would be to select from the austenitic family.

What is Chromium Carbide Hardfacing?

You’d already have an idea on what it is – from its term alone.

What Is Chromium Carbide Hardfacing
An image of chromium carbide being prepared for integration

It’s the procedure of hardfacing using chromium carbide alloys to parts and materials.

Chromium carbide are iron-based alloys that have high levels of chromium and carbon (chromium > 15%; and carbon > 3%).

Due to this chemistry, they’re able to form hard carbides that are capable of resisting highly abrasive environments.

Frequently, chromium carbide hardfaced deposits check-crack; they do about every ½ inches. What this does is it helps relieve the stress from the welding procedure.

Furthermore, they look better and more desirable in applications that need good slip materials because of their low-friction coefficient.

In general, though, the level of abrasion resistance rises when the levels of chromium and carbon increase, too. However, carbon is sought and is known to be the most influential to the abrasion resistance.

Apart from those two (2), there are other elements that are able to form other borides and carbides that assist in the increase of wear resistance in environments and temperatures with high applications.

Definition of Complex Carbides

Complex carbides are linked and connected to chromium carbide deposits that contain added vanadium, molybdenum, tungsten, as well as columbium.

These elements that are added either form their own carbides or combine their carbides with the chromium carbides they have to add to the abrasion resistance of the carbides.

Complex carbides can contain one element, two elements, three elements – even all of the elements.

The applications of these complex carbides are for severe, as well as high abrasion and heat situations.

What are Martensite Carbides?

Martensite or martensitic carbides are carbides that have a high number of packed carbides that are usually:

  • Vanadium
  • Titanium
  • Niobium

Martensite carbides are the perfect choice for applications that need deposits that are free from cracks, and also those that have the best levels of wear traits.

Furthermore, they’re perfect and ideal for these situations because weld deposits usually reveal similar characteristics of wear resistance that are expected from chromium carbide hardfacing products.

Because of the fact that these alloys are far from cracking, they’re easier to apply and to deposit when it comes to reapplication.

What is an MIG Carbide?

It’s a type where the tungsten carbide particles are sent to PS98’s molten weld puddle directly from a hopper.

After the weld bead cools, the weld deposit would have huge amounts of tungsten carbide particles that are attached in a tool steel matrix that is within the range of 55 to 60 HRC.

Because of the hardness, these carbides are able to protect loader buckets, hammers, bulldozer and grader blades, and other impact and abrasive-prone parts and components.

What are Hardfacing Patterns?

As we try to remember, the goal of hardfacing is to protect the surface of the part or component from all the different types of wear present.

What Are Hardfacing Patterns
An example of a hardfacing pattern for an excavator bucket

That’s why if you are working in an environment with sand or dirt, the hardface you should apply must be weld beads that are spaced between 6.4 mm and 38 mm apart. In addition to that, they also must be perpendicular to the flow of the abrasives.

On the other hand, if you are working in an environment with ore, slag, or rocky earth, the hardface must be weld bead ridges that are parallel or going with the flow of the materials.

What these patterns do is they protect the metallic surface against abrasion by not trapping the material such as dirt, dust, rocks, or soil.

If you are to work on clay content or soil, though, you would need a hardfacing pattern that would trap the soil onto the surface. Then, it would need to form a trapped soil layer, which will not only trap soil, but also keep it protected underneath.

Can You Use Hardness Values to Predict the Abrasion Resistant of an Alloy?

Contrary to popular belief, hardness values aren’t the ones responsible for the abrasion resistance of a particular alloy.

For example, a chromium carbide alloy and a martensitic alloy can have the same hardness. In this case, let’s say it’s 60 HRC. While they have the same hardness level, they perform differently when they’re (1) exposed to high heat, (2) placed under the same abrasive conditions, and (3) when you use and slide them across soil and rocks.

In this regard, chromium carbide alloys are better and more abrasion resistant compared to a martensitic alloy.

However, you’ll be able to count that idea in if you are going to predict and anticipate the wear that alloys can have if they’re within the same family.

For example, a chromium carbide alloy that has a hardness level of 50 HRC will definitely perform better and will be more abrasion resistant than a chromium carbide alloy that has a hardness level of 40 HRC.

To cut it simply, the microstructure of the alloy needs to be considered; and to find that out, it’s best to contact and to inquire to your manufacturer about it.

How is Wear Measured?

As we know, hardness isn’t the only thing that makes a metal “tough” and “durable.”

Apart form hardness, there are a couple of factors that allows wear to be measured. In fact, it will depend on the classification of wear that is involved.

For instance, in abrasive wear, the ASTM Intl. G65 Dry Sand Rubber Wheel Test is the test used to measure how much abrasive a part can get.

What Gas Do You Use in GMAW Hardfacing?

Because this is a more crucial welding process, argon mixtures with a bit of oxygen and/or carbon dioxide and pure argon are the best gases you can use so you arrive at the best results.

However, you’re not just limited to that. In fact, you can also make use of pure carbon dioxide.

What is a Globular Transfer or a Ball Transfer? Why is It Important?

A ball or a globular transfer utilizes gravity to transport large balls of molten electrodes from across the welding arc.

It’s important because this procedure of transferring molten metal drops is smooth. Furthermore, you can find it at the best levels whenever you are going to fuse materials that need a good level of penetration.

Do You Need to Preheat Parts Before Hardfacing?

As we mentioned above, preheating a particular part or component would depend on what it is. Generally, though, all parts that are to be welded needs to be at least at a room temperature to avoid warping.

The temperature needed for preheating will depend and be based on the base metal’s chemistry, as well as the workpiece you’ll work on.

If you’re not sure of whether or not preheating is required, talk to your manufacturer about it and ask if preheating is still needed to start and initiate the work.

When Do You Use Cobalt Hardfacing Alloys?

Cobalt alloys have a lot of carbides on its belt. In addition to that, they’re also excellent when it comes to corrosion resistance, thanks to their good magnetic properties.

Therefore, it’s ideal that you use them in applications that have high and severe temperatures and oxidation instances.

The hardness deposition rates they have range between 25 HRC and 55 HRC; they also have work-hardening alloys.

When Do You Use Nickel Hardfacing Alloys?

On the other hand, it is best and ideal to utilize nickel hardfacing alloys in highly-corrosive atmospheres and environments.

In addition to that, if you are going to work on peculiarly elevated temperatures, utilizing nickel hardfacing alloys would be the best thing to do.

Nickel hardfacing alloys also have properties that allow them to resist friction, as well as adhesion.

Why Is There a Limit of About Three (3) Layers in Some Hardfacing Products?

While hardfacing doesn’t necessarily have any type of limits, there are some prodcuts that are just limited to about three (3) to five (5) layers.

Why Is There A Limit Of Layers
There are certain materials that should follow a limit when it comes to hardfacing

Take chromium carbide for example. Chromium carbide, as a general rule, have certain limitations on the layers you can apply.

Because of its brittle nature, many layers can lead to an orchestra of check-cracking.

For you to know what the best and the most recommended number of layer is, ask your manufacturer for it. They’ll know the exact applications for it and they’ll be able to tell you the max for a hardfacing alloy.

What is a Buffer Alloy or a Build-Up?

These are alloys that are the same as the base or the parent metal when it comes to strength and hardness.

More often than not, they have two (2) primary uses: You apply them to parts and components that are severely worn out to bring the dimensions and the figure back; and you can use them as a buffer for following layers to have a more and a better wear-resistant hardfacing deposition.

Should there be cracks on your workpiece, you can always utilize a manganese product to stop the check-cracks from penetrating through the parent metal.

NOTE: You should always put in mind that a mild steel electrode is never useful for a buffer layer or as a build-up alloy. Why? – Because mild steel electrodes do not have enough strength and durability to be able to support hardfacing. If you try using it, it will immediately and easily collapse under the hardfaced layer, causing it to fail and to exhibit damage.

Can You Hardface Cast Iron?

As part of the base metals and materials that can be hardfaced, yes, you can absolutely perform hardfacing of cast iron.

However, you have to consider preheating the base metal first as well as some interpass temperatures.

Nickel-iron products, as well as Nickel products are the best for the rebuilding of cast iron. Why? – Because the carbon content of cast iron wouldn’t be affected and altered – they’ll remain ductile.

While you’ll find these questions the most asked questions about hardfacing, you shouldn’t just bank on it for all the information you need.

Depending on the manufacturer you’ll trust, you can ask and inquire to them about all the other hardfacing procedures and rules you need to know.

Here with us at WALDUN, we are equipped with the best men and the best experts when it comes to hardfacing.

We have a knowledge-base or a hub of information that you can utilize for you and your business!

Reach out to us and get the best hardfacing solutions you can get!

Hard Facing Welding Rod in Hardfacing

A welding rod is an electrode; and what this means is that it’s what you deposit to the surface of your base metal. Hardfacing Welding Rod In Hardfacing

Hardfacing electrodes or welding rods Without a hardfacing welding rod, you wouldn’t be able to apply or deposit a tougher, stronger, and a more durable material. You can choose from a wide variety of hardfacing welding rods available in the market; it’s not just limited to one (1) kind.

What are the Advantages of Hardfacing?

Why should you perform hardfacing? Does it give you any benefit or advantage at all? What Are The Advantages Of Hardfacing A damaged chute because it doesn’t have hardfacing We’ve gathered some of the most sought after advantages you can have in performing hardfacing:

Decreased Downtime Instances

Adding up an extra layer of protection to your parts and components can help it become durable. Thus, reducing the instances of breakage, damage, and downtime. This is one of the many reasons why a lot of people go with hardfacing.

Longer Lasting and More Durable Parts and Components

What’s the most common reason why some base metals get worn out? – Because of having little-to-no protection. With hardfacing, you not only get extra protection; your parts can also become abrasion and corrosion-resistant, too, making them last longer and become more durable.

Reduced Costs

A significant reduction in cost is one of the most notable benefits of hardfacing. Because of the fact that it allows base metals to be stronger, tougher, and more durable, you will have fewer needs to repair and replace them – giving you relevant reduction in cost.

Better Part Performance

Imagine a chute without any type of hardfacing – do you think they’ll function properly? They absolutely will, for a time. However, if you continue to use it without any sort of protection, it’ll be damaged – and not for long, it can break. If it has a hardfacing coating, you can expect it not to wear down easily. Making it function better and more efficiently.

Reduced Storage Space Needs

Hardfacing protects your parts and components to be worn out; reducing the need for you to store spare and back-up resources. In asking what hardfacing is, these benefits can clearly give you the answers you’re looking for. To let you know, though, these aren’t the only advantages you can get with hardfacing, there are a lot more! But, the endpoint of these benefits and advantages would fall on you gaining more savings and reducing costs!

Thermal Spraying vs. Hardfacing: How Do They Differ?

Hardfacing and thermal spraying aren’t two (2) fruits from a different tree. Thermal Spraying Vs. Hardfacing

Thermal spraying procedure in hardfacing a round workpiece As a matter of fact, thermal spraying is one of the processes used in hardfacing. Hardfacing is the more general term of material deposition over a base metal. Thermal spraying is a kind of hardfacing technique where droplets of semi-molten material are deposited, creating the coating or the hardface.

The Most Common Materials Used in Hardfacing

Now that we’re aware of the fact that hardfacing utilizes tougher and stronger material, what are the most common ones you can use for it? Most Comon Materials Used In Hardfacin

Nickel-based alloys – one of the most common materials used in hardfacing The most common materials you can apply in a hardfacing procedure includes:

  • Nickel-based alloys
  • Chromium carbide alloys
  • Stellite
  • Cobalt-based alloys
  • NOREM Alloy

What is NOREM?

If you got confused with what NOREM is, don’t worry – you’re not alone. NOREM is known as a hardfacing material developed by the Electric Power Research Institute or the EPRI. It’s a cobalt-type hardfacing alloy that is wear resistant and is known to have replaced other cobalt-based. You can find NOREM in nuclear and chemical industries, and sectors of those sorts. As of today, there are a total of eight (8) variants of NOREM, namely:

  • 02
  • 02A
  • 03A
  • 03B
  • 04A
  • 04B
  • 05A
  • 05B

Methods Used to Deposit Hardfacing

There are quite a few techniques and processes you can perform to deposit hardfacing. Methods Used To Deposit Hardfacing

A construction machinery part hardfaced using laser cladding Some of the most common welding processes include:

  • Shielded Metal Arc Welding (SMAW)
  • Oxy-Fuel Welding (OFW)
  • Electro Slag Welding (ESW)
  • Submerged Arc Welding (SAW)
  • Plasma Transferred Arc Welding (PTAW) or Powder Plasma Welding
  • Gas Metal Arc Welding (GMAW)

Apart from welding procedures, you can also perform other techniques, which are:

  • Laser Cladding
  • Thermal Spraying
  • Cold Polymer Compounds
  • Hard Paint

The goal is to be able to deposit the material onto the surface, so any of these processes is good.

Do You Need to Heat Workpieces Before Hardfacing Them?

One of the general rules of hardfacing is that all workpieces must be brought to room temp. Do You Need To Heat Workpieces Before Hardfacing Them Semi-molten material being used for hardfacing However, it’s not something you should abide by 100% of the time. In fact, some metals and alloys are required to be preheated before working on them; this will depend on the chemical composition of that alloy or metal.

Is Hardfacing Limited to Just One (1) Layer?

No, hardfacing can even go up to two (2) to five (5) layers, depending on the product. Is Hardfacing Limited To One Layer Multiple-layer hardfacing on a heavy-earth moving equipment Products that are a part of metal carbide families are just limited to just 2 to 3 layers. On the other hand, though, you can apply an unlimited amount of layers if you use austenitic and martensitic products.

Machines Used for Hardfacing 

Hardfacing isn’t a procedure you can do without any machines or equipment. Machines Used For Hardfacing One-head hardfacing machine offered by Waldun In fact, choosing the right machinery will get the job done easier, faster, and more conveniently. The machines you’ll choose will depend on the results you want to achieve. Nevertheless, here are some examples of machines you can use for hardfacing:

One and Two-Head Hardfacing Machine 

It’s a type of machine where a welding head is present. The one-head contains one (1) welding head, while the two-head has two (2). Furthermore, it has a bed where the workpiece shall be loaded. It’s a good type of machine because it reduces workforce while ensuring the quality of the hardfacing procedure.

PTA or Plasma Transferred Arc Welding Machine 

PTA welding equipment is a sort of thermal process where AR material is applied and deposited to surfaces. Compared to others, they’re considered to be flexible and versatile machines.

Pipe Hardfacing Equipment

Working on pipes is not the same as working on a flat-shaped workpiece. Pipes and tubes need a specific type of machine in order to get the work done – that’s what pipe hardfacing machines are for. It utilizes automatic arc welding and is multifunctional. These aren’t the only machines you can use to perform hardfacing – there are others, in fact, a lot more! These are just equipment widely and most commonly used.

Can You Perform Hardfacing on Excavator Buckets?

Hardfacing has a significant impact in both heavy-earth and construction industries. An Excavator Bucket Hardfaced With Durable And Tough Material An excavator bucket hardfaced with durable and tough material Therefore, performing hardfacing on excavator buckets can yield a lot of positive results, in terms of strength, durability, efficiency, and effectiveness.

Hardfacing Electrode Price

Without an electrode, you wouldn’t be able to perform hardfacing. So, the million-dollar question is, how much do they cost? To be frank, hardfacing electrodes and rods differ in prices. More so, their prices would depend on a lot of factors, including:

  • The element of the hardfacing electrode
  • Tensile strength and hardness
  • Composition

What Types of Wear Can Hardfacing Put an End To?

Depending on your industry and the use of your parts and components, hardfacing can stop many different types of wear. What Types Of Wear Can Hardfacing Put An End To Damaged pipe because it lacks hardfacing The most common ones include abrasion, corrosion, impact, friction, and heat. By performing hardfacing, you wouldn’t have to worry about these types of wear!

Is Cracking on Hardfaced Alloys Normal?

Cracking is a sign of inconsistency and breakage – therefore, it’s not normal if you look at it generally.

Is Cracking On Hardfaced Alloys Normal

Cracking on hardfaced alloy However, there are types and instances where cracking is part of its natural physicality. For instance, chromium carbide alloys show check cracks whenever they’re cooled down to median temperatures; and in this case, it’s normal. But, you always need to see cracking as a type of hint going to damage or breakage.

Can You Perform Hardfacing on New Parts?

Absolutely! As a matter of fact, most companies make this choice in order for the parts to have a longer lifespan, and to be able to function better and properly. The increased wear resistance that it has offers a domino effect on all other benefits. All of the advantages and benefits of hardfacing would also apply if you perform hardfacing on newly manufactured and produced parts and components.

Where Can You Find Good Manufacturers of Hardfacing Welding Machines?

The market is filled with a lot of manufacturers and suppliers of hardfacing materials.

But over the years, no manufacturer exceeded the capacity and the skill that the Chinese have.

China’s dominance in the hard surface welding machine industry overtook all other regions in the market.

If you’re not sure where to look for manufacturers, China might just be your best bet.

Which Manufacturer Can You Bank on With Hardfacing Welding?

Here in China, no other manufacturer of hardfacing welding equipment is trusted but us here at Waldun.

For more than a decade, our clients have continually trusted our skills and capabilities. We’re able to produce a wide variety of hard surfacing welding equipment for our clients.

Whether you need a hardfacing machine or you need your parts to be hard surfaced, Waldun is your best bet!

You can ask us to specify the machine you need; or to draw up specifications on the hardface you’re looking for!

Contact us and get the highest quality of hardfacing welding machines you can find!

  • We offer a free sample of hardfaced materials you need
  • All your orders will arrive in a maximum of 3 weeks
  • Waldun has flexible and reasonable payment plans
  • We can specify your orders to your request!

Don’t hesitate to work with the best! Get the hardfacing service or the hardfacing welding machines you need at a competitive rate!

Let’s review each of them in details.