Dissimilar Metal Welding
All welding processes have a component of dissimilar metal welding about them.
The fact that metals have to be joined is an admission that they are most probably from two different sources. By far the greatest tonnage of welding would be in joining the same general type of material - perhaps the most common situation would be in structural steel where two low-medium carbon steel components are welded together. Even in this simple case there can still be a problem if one piece is at the high end of the carbon range and the other is at the low end.
A more demanding case is where there are two quite different materials that have to be joined. This paper is designed as a review of the practice of dissimilar metal welding of this latter class of join.