B1800HS/DP1180电阻点焊接头组织研究

B1800HS/DP1180电阻点焊接头组织研究 Study on the proprieties of B1800HS/DP1180 resistance spot welding joints 凌华 LING Hua 1 first-author 孙浩 SUN Hao 2 郭亚洲 GUO Yazhou 1 樊良伟 FAN Liangwei 1 刘成杰 LIU Chengjie 3 韦习成 WEI Xicheng 2 上海汽车集团股份有限公司乘用车分公司 上海汽车集团股份有限公司乘用车分公司 SAIC Motor Passenger Vehicle Company SAIC Motor Passenger Vehicle Company 上海大学材料科学与工程学院 上海大学材料科学与工程学院 School of Materials Science and Engineering ,Shanghai University School of Materials Science and Engineering ,Shanghai University 宝山钢铁股份有限公司中央研究院汽车用钢开发与应用技术国家重点实验室(宝钢) 宝山钢铁股份有限公司中央研究院汽车用钢开发与应用技术国家重点实验室(宝钢) Research Institute,Baoshan Iron & Steel Co.,Ltd.,State Key Laboratory of Development and Application(Baosteel) Research Institute,Baoshan Iron & Steel Co.,Ltd.,State Key Laboratory of Development and Application(Baosteel) 以B1800HS/DP1180电阻点焊接头为研究对象,利用超景深显微镜观察焊缝宏观形貌,采用光学显微镜分析焊缝显微组织,并用维氏显微硬度计测试接头硬度分布。结果表明,热冲压淬火后的B1800HS组织为细小的板条马氏体。点焊接头熔核良好,其熔核呈非对称状,组织为粗大的板条马氏体,熔核直径6 500.32μm,熔核深度1 868.17μm,热影响区宽度692.63μm,电极压痕深度216.04μm,均符合日本和德国工业标准。接头最薄弱处为亚临界热影响区,其组织为回火马氏体,硬度最低,为271 HV0.3,裂纹通常在此处产生。 In this paper, B1800 HS/DP1180 resistance spot welding joint is taken as the research object. The macroscopic morphology of the weld was observed by ultra-depth micro-scopy. The microstructure of the weld was studied via optical microscope（OM） and the hardness distribution of the joint was measured by the Vickers microhardness tester. The results show that the microstructure of B1800 HS is fine lath mart-ensite. The nugget of the spot welded joint is good and asymmetric and the microstructure is thick lath martensite. The nugget diameter is 6 500.32 μm. The nugget depth is 1 868.17μm, the width of the heat affected zone is 692.63 μm and the electrode indentation depth is 216.04 μm,which conforms to the industrial standards of Japan and Germany. The weakest part of the joint is the subcritical heat affected zone,the microstructure is tempered martensite and the hardness is the lowest,271 HV0.3,where cracks are usually produced. 热冲压 B1800HS DP1180 电阻点焊 热影响区 hot stamping B1800HS DP1180 resistance spot welding heat affect zone TG453.9;U466 上海汽车工业科技发展基金项目(1827) 2022-03-08 8 50