409L铁素体不锈钢搅拌摩擦焊接接头的组织及力学性能  

Microstructure and mechanical properties of friction stir welded joint of 409L ferritic stainless steel

作　　者：孙语鸿 刘威[1] 李于朋[1] 宫文彪[1] SUN Yu-hong;LIU Wei;LI Yu-peng;GONG Wen-biao(Key Laboratory of Advanced Structural Materials,Ministry of Education,Changchun University of Technology,Changchun 130012,China)

机构地区：[1]长春工业大学教育部先进结构材料重点实验室,吉林长春130012

出　　处：《材料热处理学报》2023年第5期210-216,共7页Transactions of Materials and Heat Treatment

基　　金：吉林省科技厅重点研发项目(20220201031GX)。

摘　　要：采用W-Re合金搅拌工具对4 mm厚409L铁素体不锈钢板进行搅拌摩擦焊(FSW),利用光学显微镜、扫描电镜、电子万能试验机和显微硬度仪等研究了焊接接头的焊缝形貌、微观组织和力学性能。结果表明:采用转速为1000 r/min,焊速为80 mm/min的工艺参数可以获得力学性能良好、无缺陷的409L铁素体不锈钢搅拌摩擦焊接接头。接头焊核区组织为高度细化的等轴铁素体晶粒,平均晶粒尺寸为17.3μm,并形成了大量的小角度晶界,是母材的3.66倍。焊缝的显微硬度分布呈“抛物线”形态,焊核区的硬度最高,为143 HV0.2,焊缝各区域的力学性能均高于母材。焊接接头的拉伸断裂在母材处,断裂形式为韧性断裂。Friction stir welding(FSW)of 4 mm thick 409L ferritic stainless steel plate was carried out with W-Re alloy stirring tool,and weld morphology,microstructure and mechanical properties of the welded joint were studied by means of optical microscope,scanning electron microscopy,electronic universal testing machine and microhardness tester.The results show that the friction stir welded joint of the 409L ferritic stainless steel with good mechanical properties and no defects can be obtained by using the welding process parameters of 1000 r/min rotating speed and 80 mm/min welding speed.The stir zone(SZ)of the joint is composed of highly refined equiaxed ferrite grains with an average grain size of 17.3μm,and a large number of small angle grain boundaries are formed in the SZ,which is 3.66 times of that of the base metal.The microhardness distribution of the weld is in a“parabola”shape,the hardness of the SZ is the highest,143 HV0.2,and the mechanical properties of each zone of the weld are higher than that of the base metal.The tensile fracture of the welded joint is at the base metal,and the fracture form is ductile fracture.

关 键 词：铁素体不锈钢 搅拌摩擦焊 微观组织 力学性能 

分 类 号：TG457.11[金属学及工艺—焊接]