Surface machining effect on material behavior of additive manufactured SUS 316L

Microstructural change of the additive manufactured (AMed) SUS 316 L part via surface machining and its effects on mechanical properties are analyzed. The laminated surface layer is formed with higher hardness and higher strength comparing to the inside due to the distortion of grains through repeated melting and rapid solidification. Through the microstructure analysis of inverse pole figure and grain boundary information maps on the surface before and after surface machining, we found out how the surface layer affects the material behavior. The surface machined simple-stepped-model (SSM) specimen showed an increase in deformation by about 5.6–8.9% compared to as-built one. Moreover, in the case of the additive manufactured SSM specimen with a small corner radius, the amount of deformation increased after machining. Therefore, we believe that when the design of mechanical parts that are manufactured by AM process should be considered the surface machining effect studied in this work.