利用Nd∶YAG固体激光器对50CrNiMoVA弹簧钢进行了扫描实验, 并与W2Mo9Cr4VCo8高速钢进行了对接焊。分析讨论了激光工艺参数对焊缝成形的影响, 观察了焊接接头显微组织, 进行了焊接接头性能实验, 并讨论了焊后热处理对焊接接头组织和性能的影响。实验结果表明, 在功率为1000~1100 W、焊接速度为3 m/min、氩气保护气体流速为15 L/min的条件下, 得到的焊缝平滑、无明显缺陷、深宽比大, 且表面成形好, 焊缝强度高, 齿部材料与背部材料结合牢固。焊后经过热处理, 接头的抗弯性能和抗拉伸能力得到明显改善, 弯曲角超过90°, 焊缝沿纵向和横向均未发生开裂。锯切寿命测试结果表明, 接头符合锯带生产要求。

By using Nd∶YAG solid-state lasers, the scanning test of 50CrNiMoVA spring steels is performed, and the butt welding with W2Mo9Cr4VCo8 high-speed steels is also done. The influences of laser process parameters on weld formation are analyzed, the microstructures of welding joints are observed, the welding joint performance tests are carried out, and the effect of heat treatment on the microstructures and properties of welding joints are discussed. The test results show that, when the laser power is 1000-1100 W, the welding speed is 3 m·min-1, and the flow rate of protecting gas Ar is 15 L·min-1, the smooth welding seams without obvious defects and also with a high aspect ratio, a good surface forming, a high strength, and a firm joining between tooth and back materials can be obtained. After welding, the heat treatment makes the bending and tensile properties of joints improve obviously, and the bending angle is larger than 90°. The welding seam does not crack along the longitudinal and transverse directions. The sawing life test result shows that the joints can meet the requirements of saw belt production.