Effect of Heat Treatment on Interface Behavior and Fatigue Property of 316L/2Cr13 Multilayered Steel

Abstract

In this study, multilayered stainless steel (MLS) composed of the austenitic stainless steel 316 L and the martensitic stainless steel 2Cr13 is prepared by the cumulative rolling method. Specifically, changes in interface and fatigue properties before and after the heat treatment are verified by scanning electron microscope, tensile test, and fatigue test. In the results, it is revealed that common grains appear at the interface after the heat treatment. Although the overall mechanical properties are improved, the interfacial bonding strength is increased and the plasticity is greatly improved after heat treatment, the fatigue properties are greatly decreased simultaneously. The main cause is that during the rolling process, large deformation leads to grain fragmentation as well as the generation of a large number of subgrains, resulting in higher dislocation density and increased deformation resistance. Therefore, the fatigue performance of MLS in as‐rolled state is better than that of MLS in the heat‐treatment state. In addition, fatigue fracture analysis indicates that cracks usually initiate at the 2Cr13 layer or at the interface between the 316 L layer and the 2Cr13 layer. Ultimately, in this study, the quadratic relationship between tensile strength and fatigue limit is analyzed through fatigue ratio to predict fatigue limit.