316L不锈钢扩散焊接头组织性能分析  

Diffusion bonding of 316L stainless steel

作　　者：胡若琪 纪康康 王颖[1] 王东坡[1] 杨振文[1] HU Ruoqi;JI Kangkang;WANG Ying;WANG Dongpo;YANG Zhenwen(Tianjin University,Tianjin Key Laboratory of Advanced Joining Technology,Tianjin,300350,China)

机构地区：[1]天津大学,天津市现代连接技术重点实验室,天津300354

出　　处：《焊接学报》2023年第5期1-6,I0003,共7页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51875400);天津市科技计划项目(19ZXJRGX00100).

摘　　要：印刷电路板式换热器具有多层薄壁、微通道的结构,如何实现其高质量连接的问题亟待解决.316L不锈钢因其优异的力学性能、焊接性能与耐腐蚀性能,常用于印刷电路板式换热器的制造.文中采用真空扩散连接的方法实现了316L奥氏体不锈钢的连接,并探究了最优工艺参数,建立了工艺参数—界面组织—力学性能之间的关系.结果表明,随焊接温度升高和保温时间的延长,接头焊合率、变形率上升,晶粒尺寸增长,硬度下降,抗拉伸剪切强度先升高后降低.1000℃–60 min–10 MPa为最优参数,此时接头抗剪强度最高,为626 MPa.该参数下的断裂方式为塑性断裂,断口呈典型的韧窝花样.创新点:(1)明确了316L不锈钢真空扩散连接的最佳工艺参数.(2)明确了焊接温度和保温时间对316L不锈钢真空扩散连接显微组织、力学性能的影响规律.The printed circuit heat exchanger(PCHE)has a multilayer,thin-walled,micro-channel structure.Solving the problem of achieving its high-quality connection is urgently needed.316L stainless steel is commonly used to manufacture PCHE due to its excellent mechanical properties,weldability,and corrosion resistance.In this study,vacuum diffusion bonding was used to connect 316L stainless steel.The optimal process parameters of the diffusion bonding process were explored,and the relationship between the process parameters,interface structure,and mechanical properties was established.With increasing bonding temperature and holding time,the bonding rate,grain size,and deformation rate of the joints continue to increase,while the hardness continues to decrease.The tensile shear strength initially increases and then decreases.A temperature of 1000℃,time of 60 min,and pressure of 10 MPa are the optimal parameters,giving a maximum joint strength of 626 MPa.The fracture morphology of the bonded joint was a dimple pattern with features of ductile fracture.Highlights:(1)The optimal process parameters of 316L stainless steel vacuum diffusion bonding were clarified.(2)The effects of welding temperature and holding time on the microstructure and mechanical properties of 316L stainless steel vacuum diffusion bonding were clarified.

关 键 词：316L不锈钢 真空扩散焊 界面组织 抗拉伸剪切强度 

分 类 号：TG[金属学及工艺]