摘要
采用激光-TIG电弧复合填丝焊接6.6 mm厚的D406A超高强度钢,发现焊缝内部存在一定量气孔缺陷.利用扫描电子显微镜(SEM)、X射线探伤等方法进一步分析了焊缝内气孔形貌、分布特征及其形成机制,发现气孔内壁出现大量的C,O元素富集现象,根据线扫描分析与理论计算相结合,推测焊缝中气孔类型主要为CO气孔.在此基础上,进一步探讨了焊接工艺参数对气孔率的影响规律,通过适当增大激光功率、减小送丝速度、增大保护气流量和提高焊接速度可以有效减少气孔,使气孔率降低到1%以下,为抑制D406A超高强钢激光-TIG电弧复合填丝焊接接头气孔提供理论基础.
Laser-TIG arc hybrid welding with filler wire was applied to weld 6. 6 mm thick D406 A ultrahigh strength steel plate. And pore defects were found in the weld. The morphology,distribution and formation mechanism of pore in the weld were analyzed by scanning electron microscopy(SEM) and Xray inspection. A large amount of C and O elements can be found on the inner wall of pore. According to the linear scanning analysis and theoretical calculation,the pore in the weld was mainly caused by CO. Based on this finding,the influence of welding parameters on porosity was further discussed. By increasing the laser power properly,reducing the wire feeding speed and in-creasing the gas flow rate and welding speed,the porosity can be effectively reduced to less than 1%. The theoretical basis was provided for inhibiting the pore in D406 A ultrahigh strength steel after laser-TIG arc hybrid welded joint with filler wire.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2017年第12期114-118,共5页
Transactions of The China Welding Institution
