QP1180高强钢薄板激光焊接接头的组织与成形性能  

Microstructure and Formability of Laser Welding Joint of QP1180 High-Strength Steel sheet

作　　者：李学军 黄坚[1] 潘华[2] 陈新平[2] 华学明[1] Li Xuejun;Huang Jian;Pan Hua;Chen Xinping;Hua Xueming(Shanghai Key Laboratory of Materials Laser Processing and Modification,Shanghai Jiao Tong University,Shanghai 200240,China;Baoshan Iron & Steel Co.,Ltd.,Shanghai 201900,China)

机构地区：[1]上海交通大学上海市激光制造与材料改性重点实验室,上海200240 [2]宝山钢铁股份有限公司,上海201900

出　　处：《中国激光》2019年第3期64-71,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFB0304400)

摘　　要：在不同焊接参数下对QP1180高强钢薄板进行激光焊接试验,对接头的显微组织、显微硬度、拉伸性能及杯突成形性能进行了分析。研究结果表明:在热影响区的回火区(软化区)形成了回火马氏体组织,导致该区存在明显的软化;提高焊接速度和降低热输入可显著降低软化程度;软化区受到两侧强体的约束而得以强化,导致拉伸后最终断裂在母材处,强度与母材相当;提高焊接速度和增加焊缝偏移可显著提高杯突值,高焊接速度下的焊板垂直于焊缝开裂,具有高杯突值,低焊接速度下的焊板沿软化区平行于焊缝开裂,具有低的杯突值;随着焊缝偏移的增大,杯突值增大,偏移至30 mm时,杯突值达到母材水平。Laser welding experiments for QP1180 high-strength steel sheet are carried out at different welding parameters,and the microstructure,microhardness,tensile properties and bulge properties of the welding joint are investigated.The results show that tempered martensite is formed in tempered zone(soft zone)of heat affected zone,leading to the softening in this zone.Increasing welding speed and reducing heat input can significantly reduce softening degree.The soft zone is strengthened by the constraints,leading to the fracture in base metal,and the strength of the soft zone is equivalent to that of the base metal.Increasing welding speed and weld line offset can obviously improve the bulge test value of the welding sheet.The welding sheet obtained at high welding speed fractures perpendicular to the weld and has high bulge test value,and the welding sheet obtained at low welding speed fractures parallel to the weld along the soft zone and has low bulge test value.Bulge test value improves gradually as the weld line offset increases and approaches to that of the base metal when the offset reaches to 30 mm.

关 键 词：激光技术 超高强QP钢 激光焊接 显微组织 成形性能 

分 类 号：TG456.7[金属学及工艺—焊接]