工艺参数对建筑结构钢激光复合焊接头性能的影响

Effects of Process Parameters on Properties of Laser Composite Welded Joint of Building Structural Steel

采用不同的工艺参数对建筑结构钢Q345B进行了搅拌摩擦焊-激光复合焊接试验,并进行了显微组织、力学性能和疲劳性能的检测。结果表明,随激光功率或搅拌头旋转速度增大,接头焊核区平均晶粒尺寸先减小后增大,接头的抗拉强度、断后伸长率、接头系数、疲劳寿命则先增大后减小;采用激光功率2 W、搅拌头旋转速度1200 r/min时,接头焊核区平均晶粒尺寸低至8.4μm,接头系数、疲劳寿命分别高达95.6%、28622次。

The building structural steel Q345 B was friction stir welding-laser hybrid welded with different process parameters, and the microstructure, mechanical properties and fatigue properties of the welded joints were researched. The results show that with the increase of laser power or mixing head rotation speed, the average grain size of the weld nugget zone of welded joint first decreases and then increases. The tensile strength, elongation, fatigue life and joint coefficient of the welded joints first increase and then decrease. When the laser power is 2W and the mixing head rotation speed is 1200 /min,the average grain size of weld nugget zone of welded joint can lower up to 8.4 μm. The joint coefficient and fatigue life are as high as 95.6% and 28622 times.