初晶オーステナイトで凝固するオーステナイト系ステンレス鋼溶接金属の凝固・変態挙動

Cr-Ni系ステンレス鋼溶接金属の凝固・変態に関する研究(第1報)

抄録

Solidification and subsequent transformation behavior of two Fe-Cr-Ni stainless steel welds were investigated by using liquid-tin quenching method. One weld metal solidified as austenitic single phase solidification mode (A mode), and the other as austenitic-ferritic solidification mode (AF mode). In the weld metal solidified as A mode, both Cr and Ni were enriched in interdendritic regions during solidification, where the degree of enrichment of Cr was larger than that of Ni. The microstructural characteristics formed during solidification, concentration profiles of elements and crystallographic orientation, were similarly observed at room temperature. In the case of AF mode solidification, globular ferrite was formed through the eutectic reaction at cell boundaries. The ‹100›_r direction of the primary austenite was found to be parallel to the ‹100›_δ direction of the eutectic ferrite and the both phases were found to grow along the preferential growth directions.