Metallurgical Phenomena in Secondary Crystallization of Stainless Steels and Weld Metals

Abstract

After the solidification of stainless steel weld metal to primary crystals, mainly of a dendritic structure, during further cooling immediately recrystallization processes occur. New grain boundaries are formed which are no longer dendritic but are mainly globular or cellular in structure. Recrystallization is most pronounced in weld metals that do not undergo further transformation, i.e. weld metals which experience neither δ-γ nor γ-α transformation. These alloying ranges can be seen in Figs. 6 and 9 (pages 8, 10). They cover alloys with high chromium and low nickel contents which possess a high degree of delta ferrite. They are classified as ferritic or semi-ferritic stainless steel weld metals. The second range covers alloys with primary solidification to austenite which are classified as fully austenitic stainless steel weld metals.