Influence of pre-strain and carbon content on delayed cracking phenomenon in unstable austenitic steels

Abstract
In this paper, we study the delayed cracking phenomenon that occurs after deep drawing, at various microstructure scales. Parameters such as temperature, drawing ratio, pre-strain and chemical composition are studied. From a macroscopic point of view, the number of cracks increases with decreasing temperature or increasing drawing ratios. The higher the carbon content, the more sensitive to failure the steel is. A pre-strain favors delayaed cracking too. Martensite stress state was determined by XRD. For a given set of parameters, it is heterogeneous in a cup. Moreover it varies with drawing conditions.