Retained Austenite Transformation-Induced Residual Stress Change in Carburized 16MnCr5 Steel

ABSTRACT Carburization, a heat treatment commonly used in industries to improve fatigue performance of components, usually results in untransformed austenite in a transformed matrix of martensite or other phases. The subsequent transformation of the retained austenite due to service loading is complex and can result in the alteration of beneficial residual stresses. The amount of retained austenite decomposed under a few axial loading cases was determined by measuring the retained austenite content before and after loading of through-carburized- and carburized case only (composite)–hardened 16MnCr5 steel samples. Separate case and core stress−strain curves and the retained austenite transformation in the case layer of the composite model were used to predict the stress−strain and the residual stress behavior of the composite samples with a simple compatibility model and a finite element model.