采用光纤激光焊接方法进行重载数控铣床SAE8620H钢双联齿轮的焊接试验,并进行显微组织、力学性能、疲劳性能和X光无损检测与分析。结果表明,该接头成形性好、无明显焊接缺陷、力学性能和疲劳性能均较好,接头的抗拉强度、屈服强度、伸长率和疲劳寿命分别达到母材的96.8%、97.2%、94.0%和91.5%。 The welding experiment of SAE8620H steel double gear of heavy duty CNC milling machine was carried out by fiber laser welding method, and the microstructure, mechanical property, fatigue property and X-ray non-destructive testing and analysis were carried out. The results show that the joint has good formability, no obvious welding defects, good mechanical properties and fatigue properties. The tensile strength, yield strength, elongation and fatigue life of the joint reach 96.8%, 97.2%, 94.0 % And 91.5%.