微米级选区激光熔化316L不锈钢拉伸变形中Σ3^(n)特殊晶界的分布  

Study on special grain boundary distribution ofΣ3^(n) in micron selective laser melting of 316L stainless steel during tensile deformation

作　　者：张楠 张海武[2] 王淼辉 杜兵 张平[1] 张志豪[3] ZHANG Nan;ZHANG Haiwu;WANG Miaohui;DU Bing;ZHANG Ping;ZHANG Zhihao(China Machinery Institute of Advanced Materials Co.Ltd.,Zhengzhou 450001,China;China Academy of Machinery Science and Technology,Beijing 100044,China;University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中机新材料研究院(郑州)有限公司,郑州450001 [2]机械科学研究总院,北京100044 [3]北京科技大学,北京100083

出　　处：《焊接学报》2023年第1期33-39,I0004,共8页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助(项目号51975240);北京市自然科学基金资助(项目号2222093)。

摘　　要：利用电子背散射衍射(EBSD)技术研究了微米级选区激光熔化制备316L不锈钢横向拉伸试样和法向拉伸试样在8%、18%和28%拉伸应变下的晶界特征分布.结果表明,随着拉伸应变的增加,横向试样和法向试样的Σ3晶界比例显著增加,Σ9+Σ27晶界比例明显降低.Σ3晶界有效隔断了一般大角度晶界的贯通性.通过微矩形截面法对Σ3特殊晶界的共格/非共格特征进行测定,其中,横向试样在18%拉伸应变下以Σ3IC为主,约占60%,而法向拉伸试样在同样条件下以Σ3C为主,约占73%.进一步分析指出,非共格Σ3IC晶界的迁移并与Σ9晶界的汇合是促进拉伸应变过程中Σ3特殊晶界比例升高的原因.In this paper,electron back scatter diffraction(EBSD)technique was used to study the grain boundary characteristic distribution of 316L stainless steel transverse tensile samples and normal tensile samples prepared by micron selective laser melting under 8%,18%and 28%tensile strain.The results show that with the increase of tensile strain,the proportion ofΣ3 grain boundaries of transverse and normal samples increased significantly,while the proportion ofΣ9 andΣ27 grain boundaries decreased significantly.The connectivity of general high angle grain boundary network was effectively interrupted byΣ3 grain boundaries.The coherent/incoherent characteristics of special grain boundaries were measured by micro rectangular section method.When the transverse specimen was under 18%tensile strain,the special grain boundaries were mainlyΣ3IC,accounting for about 60%.Under the same conditions,the special grain boundaries of normal tensile specimen were mostlyΣ3C,accounting for about 73%.Further analysis pointed out that the migration of incoherentΣ3IC grain boundaries and the interaction withΣ9 grain boundaries were the reasons for the increase of the proportion ofΣ3 special grain boundaries during the tensile strain.

关 键 词：选区激光熔化 316L 塑性变形 Σ3^(n)晶界 

分 类 号：TG456.7[金属学及工艺—焊接]