Effect of Heat Treatment on Fatigue Performance of 316L Stainless Steel Fabricated by Laser Powder Bed Fusion

Abstract

The 316L stainless steel part built by laser powder bed fusion has attracted much attention in recent years. However, current studies have not systematically revealed the influence of post-heat treatment on fatigue performance. In this study, we utilized two common heat treatment processes (450 °C anneal treatment and 1050 °C solution treatment) for 316L stainless steel and then discussed their influence on fatigue life and crack growth rate. It can be found that both the heat treatment processes led to a decrease in fatigue life. The 1050 °C solution treatment can decrease crack growth rate. This can be attributed to the increase in grain size and decline of carbide at the grain boundary. The former can lead to a longer propagation path. The latter may cause more and deeper secondary cracks along the propagation path, which exhaust more energy.