本文对6mm厚的SS400碳钢进行了等离子弧焊试验,分析了SS400碳钢等离子弧焊接性,并且对焊缝进行X射线检验、力学性能及金相组织分析。试验结果表明,在选定的焊接工艺参数条件下,焊接接头性能满足要求;且焊缝成形良好。X射线检测焊接接头内不存在裂纹、未熔合、未焊透和条形缺陷;抗拉强度符合标准要求,均达到母材σb;焊缝、HAZ与母材组织均为珠光体+铁素体。 In this paper, a plasma arc welding test was carried out on 6mm thick SS400 carbon steel, the plasma arc welding of SS400 carbon steel was analyzed, and the X-ray examination, mechanical properties and microstructure analysis of the weld were also carried out. The test results show that the performance of the welded joint meets the requirements under the conditions of the selected welding parameters; and the weld formation is good. X-ray testing welded joints without cracks, unfused, incomplete penetration and bar defects; tensile strength in line with the standard requirements, have reached the base metal σb; weld, HAZ and base metal are pearlite + ferrite .