How to choose the welding wire and flux for surfacing repair?
In the process of surfacing repair of materials or workpieces, it is not only necessary to select the appropriate welding process, but also to select the appropriate welding wire and flux, so as to obtain the ideal surfacing repair quality. So what is the principle of selection of welding wire and flux used for surfacing repair?
The first is about the selection principle of welding wire for surfacing repair, which is mainly selected according to the type of steel to be welded and the performance requirements of the welded joint, and matched with the appropriate flux. Generally speaking, for low-carbon steel and low-alloy high-strength steel, welding wires that match the strength of the base metal should be selected according to the principle of equal strength.
When surfacing repair of heat-resistant steel and stainless steel, the main focus is to consider the consistency or similarity of the chemical composition of the weld metal and the base metal to meet the requirements for heat resistance and corrosion resistance; for low-temperature steel, it is mainly based on Weld low temperature toughness to match welding wire.
The second is the choice of welding flux for surfacing repair, mainly considering the reasonable matching of flux and surfacing repair welding wire, but also comprehensive consideration of weld strength, plasticity, impact toughness and crack resistance, such as low carbon steel welding structure commonly used H08A and H08MnA welding wires correspond to high-meng, high-silicon and low-fluorine fluxes and low-manganese and manganese-free fluxes.
In addition, the selection of welding wire and flux for surfacing repair is the same as other welding materials, and the welding construction conditions should also be considered comprehensively, including the plate thickness, groove form, welding position, post-weld heat treatment and welding operation conditions, etc., combined on this basis Welding productivity, production cost and other factors are selected. In this way, different combinations of welding wire and flux can be repaired by surfacing, and deposited metals with different properties or different compositions can be obtained.