Effects of Various Post-Weld Heat Treatments on Austenite and Carbide Formation in a 13Cr4Ni Steel Multipass Weld

摘要: Multipass welding procedures are common methods for 13Cr4Ni steels' fabrication and repairs. Compared to a single-pass weld procedure, the weld microstructure in multipass is more heterogeneous due complex local thermal cycles imposed by adjacent passes. Furthermore, final microstructure mechanical properties of these steels very sensitive their history which increases heterogeneities. Thus, post-weld heat treatments performed reduce heterogeneities produce relatively homogenous weld. It has been found that best option improve forming “room temperature stable austenite” phase treatments. This study focuses on effects austenite carbide formations related evolutions microhardness distribution. The shows nanometer-size carbides form at martensite lath interfaces sub-block boundaries, then higher temperatures lamellae appear locations. Results also show highest percentage achievable single-stage tempering was obtained 610 °C. When treatment lower than 610 °C, longer holding time produces softer steel while harder steel. Still, double-stage effective lowest hardness all