Most welding methods of automatic welding machines can be used for welding dissimilar metals, but the characteristics of dissimilar metals welding should still be considered when selecting welding methods and formulating process measures. According to the different requirements of the base material and the welded joints, fusion welding, pressure welding and other welding methods are all used in the welding of dissimilar metals, but they all have their own advantages and disadvantages.
Fusion welding is widely used in dissimilar metal welding. The commonly used fusion welding methods for automatic welding machines include electrode arc welding, submerged arc welding, gas shielded arc welding, electroslag welding, plasma arc welding, electron beam welding, and laser welding. Wait. In order to reduce dilution, reduce the fusion ratio or control the amount of melting of different metal base materials, usually electron beam welding, laser welding, plasma arc welding and other methods with higher energy density of the heat source can be used.
In order to reduce the penetration depth, process measures such as indirect arc, swing welding wire, ribbon electrode, and additional non-current welding wire can be adopted. But in any case, as long as it is fusion welding, part of the base metal will always melt into the weld and cause dilution. In addition, intermetallic compounds, eutectics, etc. will also be formed. In order to alleviate such adverse effects, it is necessary to control and shorten the residence time of the metal in the liquid or high-temperature solid state.
However, despite the continuous improvement and perfection of fusion welding methods and technological measures, it is still difficult to solve all the problems in welding of dissimilar metals, because there are many kinds of metals, performance requirements are diverse, and joint forms are different. In many cases, it is necessary Use pressure welding or other welding methods to solve the welding problem of specific dissimilar metal joints.