On the stress corrosion crack growth behaviour in high temperature water of 316L stainless steel made by laser powder bed fusion additive manufacturing

This paper reports a comprehensive study of the stress corrosion crack growth behaviour of laser additively-manufactured (AM) 316L stainless steel in high temperature water. A wide range of parameters and their effects were evaluated, including microstructure, heat treatment, stress intensity factor, cold work, crack orientation, oxidizing vs. reducing conditions, and porosity. Stress-relieved material exhibits anisotropic microstructure and preferred crack path along material's build direction. With high-temperature annealing, the material recrystallizes to equiaxed structure and behaves like wrought material. The retained unrecrystallized grains in an annealed AM part may not affect the cracking. Increased porosity may enhance the crack growth rate.