增材制造316L 不锈钢应力 腐蚀研究进展

Stress corrosion cracking (SCO, as an important research direction in the interdisciplinary of material mechanics and corrosion electrochemistry, is one of the main failure modes of stainless steel components. Compared with traditional wrought technology, additive manufacturing (AM) 316L stainless steel has complicated microstructurc and inherent defects including pores and lack of fusion places (LOF) caused by additive manufacturing process, resulting in more complex SCC behavior. Herein, the basic SCC behavior of 316L stainless steel was discussed in detail on the basis of the researches of AM316L stainless steel at home and abroad. The main contents include two stress corrosion mechanisms of hydrogen induced cracking and anodic dissolution. Two behavior of transgranular cracking and intergranular cracking were described. The effects of microstructurc on SCC behavior of AM316L, including twins, different crystal interface, pores, LOF, and element segregation were summarized. The current situation and advantages of three in-situ characterization methods, including electrochemical noise, high-resolution neutron diffraction and three-dimensional morphology characterization were introduced, which arc of great significance to explore the SCC behavior of AM316L. Finally, the prospective future of the research directions of SCC behavior of additive manufacturing stainless steel were proposed, including the research of SCC characteristics under high temperature irradiation environment and the principle of stress distribution and restructuration at crack tips.