脉冲激光焊缝的焊点重叠率与凝固特征关系的研究  

Relationship Between Overlap Rate of Weld Spots and Solidification Characteristic for Pulsed Laser Welding

作　　者：洪永昌[1] 张武[2] 

机构地区：[1]安徽工业大学工商学院,安徽马鞍山243002 [2]马鞍山钢铁股份有限公司汽车板推进处,安徽马鞍山243002

出　　处：《热处理》2014年第4期13-18,共6页Heat Treatment

摘　　要：采用SW-500型Nd:YAG固体脉冲激光器对厚度1.0 mm的M170P汽车用薄钢板进行了焊接性试验。研究了脉冲激光工艺参数对焊缝表面脉冲激光焊点重叠率的影响,分析了焊缝的凝固特征。结果表明,焊缝表面脉冲激光焊点的重叠率主要受焊接速度和脉冲频率的影响,当脉冲激光焊点重叠率为70%左右时,焊缝具有良好的表面成形性。采用"适度熔透"模式形成的焊缝,其横向截面形状基本呈倒梯形,纵向截面的凝固特征线整体弯曲度较小,呈等距离分布;而采用"过度熔透"模式形成的焊缝,其横向截面形状呈双曲线形或梯形,纵向截面凝固特征线中间的弯曲度较大,类似鳞片状分布。A test for weldability of 1 mm thick M170P thin sheet for automobile was perforemed by SW-500 Nd： YAG solid pulsed laser. The effect of pulsed laser process parameters on overlap rate of pulsed laser weld spots at the welding seam surface was investigated. The solidification characteristics of the welding seam was analyzed. The results show that the overlap rate of the pulsed laser weld spots at the welding seam surface is mainly affected by the welding speed and pulse frequency, and that when the overlap rate of pulsed laser welding spots is large as about 70%, the welding seam offers good surface formability. Furthermore, the cross section of the welding seam developed by ＂moderate penetration＂ is approximate to an inverted trapezoid, and the solidification characteristic lines of the longitudinal section offer less crooked and equidistant distribution on the whole, whereas the cross section of the welding seam developed by ＂over-penetration＂ is a hyperbola-type or trapezoid, and the solidification characteristic lines of the longitudinal section is relatively crooked and approximate to squamous in the middle.

关 键 词：激光 固体脉冲激光器 脉冲频率 焊点重叠率 焊缝 凝固特征线 

分 类 号：TG115.6[金属学及工艺—物理冶金]