退火热处理对不同构建方向上激光选区熔化316L不锈钢的各向同性增强机理  

Mechanism of Isotropic Enhancement of Selective Laser Melted 316L Stainless Steel Under Different Build Directions by Annealing Heat Treatment

作　　者：蒯立群 鲁干 鲁金忠[1] 罗开玉[1] Kuai Liqun;Lu Gan;Lu Jinzhong;Luo Kaiyu(School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)

机构地区：[1]江苏大学机械工程学院,江苏镇江212013

出　　处：《激光与光电子学进展》2024年第23期315-329,共15页Laser & Optoelectronics Progress

基　　金：国家重点研发计划“增材制造与激光制造”重点专项(2023YFB4606000)。

摘　　要：系统地研究了不同退火热处理工艺对不同构建方向上激光选区熔化(SLM)316L不锈钢拉伸性能的影响。结果表明,不同构建方向的SLM试样存在显著的拉伸性能各向异性。经过950℃退火热处理0.5 h,0°、45°和90°试样的延伸率显著提高了20.21%、31.54%和16.93%,而极限抗拉强度略微降低了7.05%、3.35%和2.19%。同时,0°、45°和90°试样的胞状晶粒的平均尺寸分别减少了34%、51%和46%,平均位错密度分别减少了5.71%、10.00%和43.62%。此外,不同构建方向的SLM试样均发生了不同程度的再结晶。细晶强化、低位错密度和再结晶的协同作用促使不同构建方向的SLM试样的韧性和各向同性都得到了显著提高。最后,揭示了退火热处理对不同构建方向的SLM 316L不锈钢各向同性的增强机制。This study systematically investigated the effects of different annealing heat treatment processes on the tensile properties of selective laser melted(SLM)316L stainless steel in different build directions.The results show that significant tensile property anisotropy is present in the SLM specimens in different build directions.The elongation of the 0°,45°,and 90°specimens significantly increase by 20.21%,31.54%,and 16.93%,respectively,whereas the ultimate tensile strength values slightly decrease by 7.05%,3.35%,and 2.19%,respectively,after annealing heat treatment at 950℃ for 0.5 h.In addition,the average sizes of the cellular grains of the 0°,45°,and 90°specimens are reduced by 34%,51%,and 46%,respectively,and the average dislocation densities decrease by 5.71%,10.00%,and 43.62%,respectively.Recrystallization occurs in the SLM specimens in different build directions.The synergistic effects of fine grain strengthening,low dislocation density,and recrystallization contribute to the significant improvements in toughness and anisotropy of the SLM specimens in different build directions.Finally,the enhancement mechanism of annealing heat treatment on the anisotropy of the SLM 316L stainless steel in different build directions is revealed.

关 键 词：激光选区熔化 316L不锈钢 退火热处理 拉伸性能 各向异性 

分 类 号：TN249[电子电信—物理电子学]