中文摘要：

采用脉冲激光焊技术焊接304不锈钢薄板。利用光学显微镜、扫描电镜、万能试验机等分析检测手段,研究304不锈钢焊接接头的微观组织特点及激光功率对接头组织及力学性能的影响规律。结果表明,焊缝中心为细小的等轴晶,焊缝边缘为柱状晶组织,热影响区不明显。随着激光功率的增加,焊缝抗拉强度增大。激光功率为2.6 kW时,焊缝抗拉强度达到最大值491.7 MPa。继续增加激光功率,焊缝组织粗化,焊接接头抗拉强度降低。拉伸试样均在焊缝处发生断裂,焊缝中心是焊接接头最薄弱的部位。

英文摘要：

The 304 stainless steel sheet were joined by using pulsed YAG laser welding. The microstructure characteristics and influence of laser power parameter on microstructures and mechanical properties were observed by optical microscopy,scanning electronic microscopy and universal mechanical testing machine,et al. Experiment results showed that fine equiaxed crystal in the weld center and columnar crystal in the toe of the weld. With the increase of power input, the tensile strength get increase. The highest tensile strength of the welded joints reaches to 491.7 MPa when the laser power is 2.6 kW. The microstructure of the weld joints have coarsening tendency and the tensile strength get decrease when continue to increase the laser power. The stainless steel sheet broke at the welded joints for all tensile test samples. The weld center is the weakest region of the welded joints.