Recovery-Assisted Abnormal Grain Evolution of Selective Laser-Melted 316L Stainless Steel at Intermediate Temperatures

Selective laser-melted 316L stainless steel (SLM 316L SS) holds significant potential for application in the energy and chemical sectors owing to its commendable mechanical properties and corrosion resistance. However, the intricate process of microstructure evolution in SLM 316L SS at intermediate temperatures, encompassing the feasible range of service temperatures, needs to be more adequately comprehended. This research endeavors to elucidate the grain size and distribution alterations between 750 °C and 850 °C. Abnormal grain growth before recrystallization and re-refinement phenomena were observed, which deviated from conventional expectations. The texture was found to play a crucial role in former, while recovery-induced dislocation rearrangement and recrystallization nuclei formation contributed to the latter process. These findings provide new insights into the thermodynamic behavior of SLM 316L SS at medium to high temperatures. Graphical Abstract: (Figure presented.)