What can occur when welding dissimilar metals?

When welding dissimilar metals, one significant concern is the risk of differential thermal expansion and potential cracking. This arises because different metals can expand and contract at different rates when subjected to heat. If two metals with varying coefficients of thermal expansion are improperly welded together, the stress caused by the differing expansion can lead to cracks, particularly as the weld cools and solidifies.

In situations where dissimilar metals are being joined, close attention to the welding parameters and the materials' properties is crucial. Effective methods, such as preheating and post-heating treatments, may be employed to alleviate these stresses and minimize the risk of cracking.

In contrast, while enhancing corrosion resistance, eliminating residual stresses, or improving aesthetics could be benefits associated with some types of welding processes, they do not directly address the issues presented by differential thermal expansion. Such advantages may not always apply, especially in cases of dissimilar metal welding, where the focus should remain on managing the physical and chemical compatibility of the metals being joined.