热轧高强钢DP780的激光焊接接头组织及性能研究  

Research on the microstructure and properties of hot-rolled high strength steel DP780by laser welding

作　　者：王威[1,2] 黄继华[2] 张永强[1] 贾松青[1] 刘兴全[1] 张宝 

机构地区：[1]首钢技术研究院,北京100043 [2]北京科技大学材料科学与工程学院,北京100083 [3]北京首钢冷轧薄板有限公司,北京101304

出　　处：《电焊机》2014年第9期81-86,共6页Electric Welding Machine

摘　　要：采用12000W的CO2激光器,通过激光焊接+激光热处理的工艺对热轧高强钢DP780进行激光填丝焊接试验研究,利用光学显微镜、显微硬度计、万能试验机、抗凹试验机等分析测试手段,研究DP780-DP780自焊和DP780-SPHC过渡焊的焊接接头宏观、微观组织特点及接头力学性能的差异。试验结果表明:不同匹配方式的焊缝组织均由板条马氏体和贝氏体构成,DP780-DP780时焊缝中心到两侧母材的金相组织、显微硬度值分布均匀,焊接接头的力学性能优于母材;DP780-SPHC时焊缝中心到两侧母材的金相组织、显微硬度值均有较大差异,接头的力学性能略高于SPHC母材。A CO2 laser with an output power of 12 000 W was used to join the hot-rolled high strength steel DP780 in laser penetration butt welding process.The technology of laser welding and heat treatment.The differences in the characteristics and mechanical properties of joint macro,microstructure of weld joint of DP780-DP780 welding and DF780-SPHC were investigated by means of optical microscope ,micro hardness tester, universal testing machine,dent resistance testing machine and other analytical tests.The results showed that the weld metal mainly included lath martensite and bainite.The microstructure and microhardness from welding center to both sides of the parent material in welded joints of DP780-DP780 were uniform distribution, and mechanical properties of welded joints were better than the base metals.The larger differences in the microstructure and microhardness from welding center to both sides of the parent material in welded joints of DP780-SPFC,and the mechanical properties of welded joints were slightly higher than that of SPHC base metal, energy inputs and wire melting speed by welding experiment,it shows that this system can be applied to sheet metal welding.

关 键 词：激光焊接 热轧高强钢 DP780-DP780自焊 DP780-SPHC过渡焊 

分 类 号：TG456.7[金属学及工艺—焊接]