Metallurgical Processes Occurring During Solidification and Cooling in Stainless Steel Weld Metal
In steel, the cast structure of ingots is largely modified and positively influenced by hot forming and heat treatment operations, with processes of recrystallization, homogenization of segregations and the elimination of harmful precipitations through solution annealing playing a decisive role. In weld metals, such possibilities are rather limited, since welded components can only in rare instances be hot formed, solution annealed or quenched and tempered. In the untreated condition, weld metal normally emerges with a solidification structure and with previously executed passes of multilayer welds being exposed to a short reheating cycle in the course of depositing subsequent weld passes. But due to the steep temperature gradient, the high cooling rate and the short time span this reheating is in no way comparable to the controlled heat treatment processes of steels. Furthermore, only part of a previously laid pass is influenced in this way and the rest is maintained as a solidification structure.
KeywordsWeld Metal Weld Pool Weld Bead Sigma Phase Precipitate Crystal
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