文献类型：期刊文献

英文题名：Creep behavior and fracture mechanism of an additively manufactured 316L stainless steel with extraordinary creep resistance

作者：Pan, Yujie[1];Hu, Huayan[2];Wang, Kangkang[1];Dong, Naijian[1];Qiu, Rui[1];Wen, Jian-Feng[1,3];Song, Miao[2];Tu, Shan -Tung[1,3]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[2]Shanghai Jiao Tong Univ, Sch Nucl Sci & Engn, Shanghai 200240, Peoples R China;[3]Shanghai Inst Aircraft Mech & Control, Shanghai 200237, Peoples R China

年份：2024

卷号：196

外文期刊名：MECHANICS OF MATERIALS

收录：;EI(收录号：20242316218522);WOS:【SCI-EXPANDED(收录号:WOS:001256464400001)】；

基金：We gratefully acknowledge the financial support of National Natural Science Foundation of China (No.52122506 & 51875203) , National Science and Technology Major Project (J2019 -IV -0010-0078) , Shanghai Gaofeng Project for University Academic Program Development and the Program of Oriental Scholars of Shanghai Universities. HYH and MS were supported by National Natural Science Foundation of China (No.12275176) and China National Nuclear Corporation LingChuang Project. We acknowledge the access to microscopes at the Instrumental Analysis Center at Shanghai Jiao Tong University.

语种：英文

外文关键词：Additive manufacturing; 316L stainless steel; Creep behavior; Creep fracture; Creep resistance; Dislocation cell

摘要：The creep behaviors of laser powder bed fusion (LPBF) additively manufactured (AM) 316L stainless steel (SS) and its recrystallized (Re) counterpart were investigated via uniaxial constant -load creep tests at 600 degrees C with nominal stress levels ranging from 235 to 360 MPa. Anisotropic creep behavior was observed in AM 316L SS, with superior creep resistance but inferior creep ductility in the horizontal sample (loaded perpendicular to the build direction (BD)) compared to the vertical sample (loaded parallel to the BD). This superior creep resistance was likely resulted from shorter dislocation slip distance and the inferior creep ductility was due to faster propagation of cracks along the columnar grain boundaries. Compared with both the Re counterpart and conventional 316L SS, AM 316L SS in this study exhibited an extraordinary creep resistance at various stress levels, with the minimum creep rate being two to three orders of magnitude lower and much longer creep life. This exceptional creep resistance of AM 316L SS was attributed to the presence of dislocation cells that impeded the deformation -induced dislocations. This led to a remarkably low rate of creep deformation and delayed the creep crack initiation, ultimately resulting in a long creep life. The gradual development of the precipitate films enriched with Mo, Si and Cr along high -angle grain boundaries, following prolonged exposure to high temperatures, was found to restrict the creep ductility in AM 316L under low stress conditions. Nevertheless, the study demonstrates that the stable dislocation cells are beneficial in enhancing the high -temperature creep resistance of AM 316L SS.