SUS301L不锈钢冷金属过渡焊接接头焊接工艺、微观组织及力学性能

摘要

随着我国轨道交通行业的飞速发展,车体减重对于节省能源意义重大.采用CMT冷金属过渡焊接技术对4-0.8 mm SUS301L-MT不锈钢搭接接头进行了工艺研究,获得最优工艺参数;同时,对焊接接头进行了宏观形貌、微观组织观察、力学性能以及变形测量.结果表明,在最优工艺参数下,焊缝成形美观,无明显缺陷,焊缝区组织主要为奥氏体柱状晶和枝晶状铁素体;焊接接头拉伸剪切最大力达到了22 234.42 N,硬度测试最小值均出现在焊缝区;焊后试板呈现波浪变形,最大Z方向变形量出现在试板边缘.%With the rapid development of the rail transportation industry in our country,the weight reduction of the train body has great significance for energy saving.The 4-0.8 mm lap joints of SUS301L-MT stainless steel are studied by using CMT welding technology,and the optimal welding parameters are obtained;The macroscopic morphology and microstructure observation,mechanical properties and deformation measurement of welded joints are carried out.The results show that under the optimal parameters,the appearance of weld forms well without obvious defects.The microstructure of the weld zone is mainly austenite columnar crystal and dendritic crystal ferrite.Besides,the maximum tensile-shear of welded joints reach 22 234.42 N,and the minimum value of hardness test appears in the weld zone.After welding,the test plate shows wave deformation and the maximum Z direction deformation occurs at the edge of the test plate.