Sammendrag
Two-pass weld simulation has been used to investigate the precipitation mechanism of carbides in the coarse grained HAZ of two supermartensitic stainless steels, one high-grade containing titanium and one medium-grade without titanium. Recently, a model for such carbide precipitation was suggested.1 According to this model, a reheating of the HAZ in the martensitic stage is needed to provoke strong carbide formation. In the present work, the peak temperatures of the first and the second heating passes, the holding time during the second (reheating) pass, and the temperature of the holding between the two passes have been varied in order to find the most favorable conditions for the carbide precipitation in the two steels. In addition, measurements of the chromium content across prior austenite grain boundaries have been made for the titanium free steel.
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