Phase-field simulation of sensitization behavior in austenitic stainless steel weld metal with delta-ferrite existence

Abstract

The sensitization behavior in austenitic stainless steel weld metal was simulated using the phase-field method. The simulations were performed for two cases that δ-ferrite does and does not exist in austenitic phase. The calculation results revealed that the Cr-depleted zones do not form both in the vicinity of γ/M₂₃C₆ and δ/M₂₃C₆ when δ-ferrite exists. On the other hand the Cr-depleted zones form in the interface of γ/M₂₃C₆ in the austenitic stainless steel when δ-ferrite dose not exist. The suppression of the formation of Cr-depleted zone can be explained by the model that carbon atoms in the austenitic phase are consumed due to rapid growth of M₂₃C₆ in δ-ferrite.