Intergranular corrosion metals processing

Other methods of metal powder manufacture are also employed for specific metals. Selective corrosion of carbide-rich grain boundaries in stainless steel, a process called intergranular corrosion, also yields a powder. 

From the corrosion viewpoint, welding is a particularly troublesome treatment. Because welding involves the local heating of a material, it can lead to phase transformations and the formation of secondary precipitates. It can also induce stress in and around the weld. Such changes can lead to significant local differences in electro-chemical properties, as well as the onset of such processes as intergranular corrosion. Therefore, the weld filler metal should be as close in electro-chemical properties to the base metal as technically feasible, and the weld should be subsequently stress relieved. 

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