研究了铸造镍基高温合金（Ｋ３）激光焊接时工艺参数对焊缝熔深及熔宽的影响．讨论了焊缝及热影响区产生热裂纹的机制及防止措施．结果表明，采用合适的激光焊接工艺可得到有较高强度、没有裂纹和气孔等焊接缺陷的接头． The effect of process parameters on weld penetration and weld width during casting of nickel-base superalloy (K3) was studied. The mechanism and prevention measures of hot cracks in weld and heat affected zone are discussed. The results show that using suitable laser welding technology can obtain a joint with higher strength, no welding defects such as cracks and pores.