低碳贝氏体钢激光-电弧复合焊接工艺及组织性能研究  

Laser-Arc Hybrid Welding Process and Microstructure and Properties of Low Carbon Bainite Steel

作　　者：梁盈 蔡创 陈辉[1] 张志毅 LIANG Ying;CAI Chuang;CHEN Hui;ZHANG Zhiyi(College of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;CRRC Qingdao Sifang Co.,Ltd.,Qingdao 266111,China)

机构地区：[1]西南交通大学材料科学与工程学院,四川成都610031 [2]中车青岛四方机车车辆股份有限公司,山东青岛266111

出　　处：《热加工工艺》2022年第3期48-53,59,共7页Hot Working Technology

摘　　要：采用10kW激光器对10mm厚低碳贝氏体钢进行激光-电弧复合焊接,探究激光功率、送丝速度、焊接速度对成型的影响规律,优化焊接工艺,分析研究激光-电弧复合焊接接头各微区组织、硬度、拉伸、冲击性能。结果表明,优化的工艺参数区间为:激光功率4.0〜4.3 kW,送丝速度13〜13.5 m/min,焊接速度14〜15 mm/s;焊缝组织主要为板条贝氏体、针状铁素体和少量马氏体,热影响区组织以板条和粒状贝氏体为主,还有较少M-A组元、铁素体、马氏体;由于焊接热循环作用,硬度存在明显差异,热影响区硬度最高,其次是焊缝,两者均高于母材;焊接接头拉伸破坏都发生在远离焊缝的母材,断裂位置出现明显的颈缩现象,焊接接头拉伸性能好;相对于母材,各微区冲击韧性明显降低,热影响区较好,焊缝最低。总体而言,焊缝区强度高、韧性低,热影响区强度低、韧性高。A 10 kW laser was used for laser-arc hybrid welding of a low-carbon bainite steel with a thickness of 10 mm.The influence of laser power,wire feeding speed and welding speed on the forming was investigated.The welding process was optimized,and the microstructure of each region,hardness,tensile and impact mechanical properties of the joint were studied.The results show that the optimized process parameters can be determined as laser power of 4.0-4.3 kW,wire feeding speed of 13-13.5 m/min,welding speed of 14-15 mm/s.The microsturcture of the weld metal is mainly lath bainite,acicular ferrite and a small amount of martensite,the microstructure of the heat affected zone is mainly lath and granular bainite,and a few M-A components,ferrite,martensite.Due to the heat cycle of welding,there is a significant difference in hardness.The hardness of the heat affected zone is the highest,followed by the weld,both of which are higher than that of the base metal.The tensile failure of the welded joint is at BM away from the weld,and there is obvious necking phenomenon at the fracture location,the welded joint has good tensile properties.Compared with that of the base metal,the impact toughness of each micro zone is significantly reduced,that of the heat affected zone is better,and the weld has the lowest impact toughness;overall,the weld zone has high strength and low toughness,while the heat-affected zone has low strength and high toughness.

关 键 词：低碳贝氏体钢 激光-电弧复合焊接 微观组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]