Tensile and creep behavior of 316L austenite stainless steel at elevated temperatures: experiment and crystal plasticity modeling

In a high-temperature environment, creep rupture is the major failure mode of metallic materials. 316L austenite stainless steel has been widely used in nuclear reactors for its extraordinary creep strength and corrosion resistance. In this work, the uniaxial tensile deformation and creep behavior of 316L austenite stainless steel at elevated temperatures are investigated. Firstly, the result shows that 316L austenite stainless steel has an obvious temperature-dependent dynamic strain aging at a specific temperature range (723 K–923 K) with a strain rate of 1.3×10 −3 s −1 . Furthermore, at elevated temperatures, dislocation climb is the main creep mechanism of 316L austenite stainless steel and can affect dislocation mobility. Then, a dislocation-based crystal plasticity model is established to describe the relationship between the macroscopic mechanical responses and the underlying microscopic dislocation behaviors. Especially, the dislocation climb leads to the annihilation of monopolar dislocations and the formation of dislocation dipoles and helps monopolar dislocations surmount obstacles. Finally, the developed constitutive model is verified to simulate the uniaxial tensile and creep responses of 316L austenite stainless steel at elevated temperatures. The established model is expected to provide a theoretical basis for evaluating the high-temperature creep properties of metallic materials.