激光填粉焊接B340LA高强钢工艺特性研究  

Process Characteristics of Laser Powder Filling Welding of B340LA High-Strength Steel

作　　者：李洁 张屹[1,2] 梁志超[1,2] 陈聪 Li Jie;Zhang Yi;Liang Zhichao;Chen Cong(State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,Hunan,China;Hunan Provincial Key Laboratory of Intelligent Laser Manufacturing,Hunan University,Changsha 410082,Hunan,China)

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,湖南长沙410082 [2]湖南大学智能激光制造湖南省重点实验室,湖南长沙410082

出　　处：《激光与光电子学进展》2023年第17期301-308,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51975205);湖南省自然科学基金(2021JJ40068)。

摘　　要：激光焊接B340LA高强钢是汽车轻量化设计制造的重要技术难题。采用Fe30金属粉末作为填料开展了B340LA高强钢激光填粉焊接工艺试验,研究了对接间隙、焊接速度和填粉速度对焊缝质量的影响规律,发现在优化工艺参数条件下,可以得到焊缝形貌平整,焊缝强度高于母材的优质焊缝。结果表明,对接间隙是影响表面余高和塌陷的最重要工艺参量,随着对接间隙的增大,焊缝形貌下凹量增大,当对接间隙为0.15 mm时,焊缝出现塌陷。焊接速度对焊缝表面余高和塌陷影响较小,随着焊接速度的增加,焊缝形貌平整,未出现塌陷现象。填粉速度对抗拉强度的影响较大,随着填粉速度的增加,焊接件的组织大范围细化,抗拉强度增加。当填粉速度<8.27 g/min时,焊接接头断裂在焊缝位置;当填粉速度≥8.27 g/min时,焊接接头断裂在母材,此时焊接接头强度高于母材。该研究成果丰富了激光焊接基础理论,为车用B340LA高强钢激光焊接提供技术支撑。Laser welding of B340LA high-strength steel is crucial for lightweight designing and manufacturing of automobiles.In this study,Fe30 metal powder was employed as a filler to perform B340LA high-strength steel laser powder filling welding,and the effect of the butt gap,welding speed,and powder feeding rate on weld quality was investigated.Furthermore,a high-quality weld with smooth weld morphology and better weld strength compared to base metal was obtained under optimized process parameters.Moreover,the butt gap was the most important process parameter affecting surface clearance and collapse,and the concave amount of the weld profile increased as the butt gap increased.However,when the butt gap was 0.15 mm,the weld collapsed.Welding speed had little effect on weld surface reinforcement and collapse.As the welding speed increased,the weld morphology became flat,and no collapse was observed.Furthermore,the powder feeding rate significantly influenced the tensile strength.As the powder feeding increased,the microstructure of the weldments was refined at a wide range,and the tensile strength increased.When the powder feeding rate was less than 8.27 g/min,the fracture of the welded joint occurred at the weld.However,when the powder feeding rate was≥8.27 g/min,the welded joint broke at the base metal,and the strength of the welded joint was higher than that of the base metal.The research results enrich the basic theory of laser welding and provide technical support for B340LA high-strength steel laser welding of vehicles.

关 键 词：激光技术 激光焊接 工艺特性 焊缝形貌 抗拉强度 高强钢 

分 类 号：TG456.7[金属学及工艺—焊接]