Determination of recrystallisation phenomenon in type 316 stainless steel VIM-VAR ingots during cogging operations

Abstract. This study is focused on understanding the effects of key process parameters onset recrystallisation coarse, elongated, and dendritic grains as-cast microstructure during ingot-to-billet conversion, consisting successive cogging, upsetting, reheating operations, in type 316 austenitic stainless steel. The microstructural characteristics initial ingot (e.g., size, orientation morphology grains), complex thermo-mechanical path have significant impact behaviours, which make existing material models inefficient precise prediction. These investigations aim at exploring mechanisms their dependency forging parameters. Cogging trails were conducted VIM-VAR steel ingots observations made to identify mechanisms. Finite element simulations coupled with constitutive developed parallel, enable microstructurally informed prediction cogging process. Thus, static discontinuous dynamic recrystallisations occur succession after reaching a threshold level deformation cogging. Grain growth occurred statically recrystallised reheating. importance associated efficiency billet conversion terms grain refinement thus highlighted.