中国激光, 2009, 36 (s1): 147, 网络出版: 2009-06-18
K418涡轮盘与42CrMo涡轮轴异种金属激光焊接
Dissimilar Metal Laser Welding of Cast Ni-Based Superalloy K418 Turbo Disk and Alloy Steel 42CrMo Shaft
摘要
研究了镍基高温合金(K418)涡轮盘与合金钢(42CrMo)轴异种金属的激光焊接。通过光学显微镜(OM)、扫描电镜(SEM)分析了焊缝区域组织。结果表明, 侧吹保护气流量大, 焊缝收尾处易形成鼓包缺陷; 由于K418与42CrMo热物性的差异, 焊缝易偏向K418且焊缝与K418交界易剥离; 焊缝与母材交界组织为具有一定方向的枝晶组织。在扫描电镜下焊缝区域观察到了颗粒状的Laves相。由于K418和42CrMo混合比例和冷却速度的差异导致焊缝不同区域颗粒状的Laves相的致密度不同。
Abstract
Dissimilar metal laser welding of cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft was studied. Microstructure of the welded seam was characterized by optical microscopy (OM) and scanning electron microscopy (SEM). Results showed that side-blow shielding gas was warped in the melt pool with excessive flow rate of shielding gas by progressively reducing of heat input of laser. Bubble defect of seam ending can be inhibited by optimizing flow rate of side-blow shielding gas. Microstructure of the weld and base metal interface is mainly composed of dendrites whose growing direction is nearly parallel to the negative heat-transfer direction. Distribution of Laves phase have discrepancy in different region of the welded seam because of different mixing proportion of K418 and 42CrMo,and different solidifying velocity in different region of the melting pool.
庞铭, 谭建松, 王建平, 吴波, 解志民, 胡定云, 虞钢. K418涡轮盘与42CrMo涡轮轴异种金属激光焊接[J]. 中国激光, 2009, 36(s1): 147. Pan Ming, Tan Jiansong, Wang Jianping, Wu Bo, Xie Zhimin, Hu Dingyun, Yu Gang. Dissimilar Metal Laser Welding of Cast Ni-Based Superalloy K418 Turbo Disk and Alloy Steel 42CrMo Shaft[J]. Chinese Journal of Lasers, 2009, 36(s1): 147.