焊接速度对激光-电弧复合焊接焊缝成形和低温冲击韧性的影响  

Effect of Welding Speed on Bead Appearance and Low-Temperature Impact Toughness in Laser-Arc Hybrid Welding

作　　者：邹德敏 齐锦刚[2] 赵琳[1] 曹洋[1] Zou Demin;Qi Jingang;Zhao Lin;Cao Yang(Welding Institute,Central Iron&Steel Research Institute,Beijing 100081,China;College of Materials Science and Engineering,Liaoning University of Technology,Jinzhou,Liaoning 121001,China)

机构地区：[1]钢铁研究总院焊接研究所,北京100081 [2]辽宁工业大学材料科学与工程学院,辽宁锦州121001

出　　处：《中国激光》2022年第8期145-154,共10页Chinese Journal of Lasers

基　　金：“十三五”装备预研共用技术项目(41422010105);钢铁研究总院自主投入研发专项项目(事21H62630B)。

摘　　要：开展了440MPa级船用高强钢激光-电弧复合焊接试验,研究了焊接速度对焊缝成形和低温冲击韧性的影响规律。结果表明,焊接速度对焊缝成形具有较大影响:焊接速度较小时,焊接热输入较大,熔池易塌陷;焊接速度较大时,由于激光能量密度不足,激光小孔熔透不稳定,焊缝底部易形成驼峰。随着焊接速度增大,440 MPa级船用高强钢激光-电弧复合焊接焊缝的低温冲击韧性呈先增加后降低的趋势:当焊接速度低于1.0m/min时,焊缝的-40℃冲击吸收功较低,小孔型气孔是主要影响因素;当焊接速度为1.2m/min时,气孔倾向小,焊缝的冲击吸收功达到了175J;当焊接速度增加到1.5m/min以上时,贝氏体含量较大,焊缝的低温冲击吸收功下降。Objective Welding technology is crucial for ship manufacture,accounting for between 30%--50%of shipbuilding costs.To further develop the shipbuilding industry,it is necessary to increase the efficiency and quality of ship welding.Gas shielded welding and submerged arc welding are both frequently employed in ship manufacturing currently.Welding at a slow pace and a high heat input leads to significant welding deformation and low efficiency.As a welding method that incorporates both a laser beam and an arc into one process,laser-arc hybrid welding offers many advantages,including rapid welding speed,low heat input and excellent weld microstructures when the filler wire is utilised.Due to these advantages,laser-arc hybrid welding is a viable choice for manufacturing sectional steel structures in the shipbuilding sector,as it may reduce welding deformation and improve welding efficiency.As a result,laser-arc hybrid welding of 440 MPa grade high-strength marine steel at various welding speeds was performed.The effect of welding speed on the bead appearance and root humping was examined,as well as its effect on the toughness of hybrid welds.Methods Laser-arc hybrid welding of 8 mm thick 440 MPa-class marine high-strength steel was accomplished by employing a welding system comprised of a 6kW fibre laser and a molten metal gas shielded welding machine(Fig.1).The laser wavelength is 1070nm and has a nominal focusing spot of approximately 0.4mm.Between the laser beam and the electrode axis,the angle was 35°.The laser power and defocus distance were 6kW and-3mm,respectively,in the welding direction of the leading laser.A constant filler wire feed rate of 6m/min was utilised.The arc current and voltage were 185A and 22V,respectively,with 98%Ar-2%O_(2) shielding gas.To capture and study the formation of root humping,a high-speed camera was used.Following welding,the porosity in weld metal was determined utilising non-destructive X-ray testing equipment.The metallographic samples were then cut,ground,polished and finally etc

关 键 词：激光技术 激光-电弧复合焊接 低合金高强钢 焊缝成形 底部驼峰 冲击韧性 

分 类 号：TG456.9[金属学及工艺—焊接]