SUS301L薄板不锈钢脉冲激光焊接头的组织特点与硬度分布

Microstructure characteristics and hardness distribution of pulsed laser welded SUS301L stainless steel sheet joint

利用脉冲激光焊进行了SUS301L薄板不锈钢的对接焊接实验,分析了此种焊接方法的工艺特点、接头的微观组织和硬度。结果表明,随脉冲电流和脉冲宽度变化,焊缝表面形貌变化明显,焊缝熔深熔宽随焊接线能量显著变化,焊缝组织主要为奥氏体加少量的铁素体,焊缝边缘主要为柱状晶,其生长方向近似垂直于熔合线,焊缝中心主要为胞状晶,焊接接头横截面具有近似"杯"状的特点,焊接接头的硬度分布呈"W"状。

The pulse laser welding method was used in the butt welding of SUS301 L stainless steel plates in this article. The features in the welding process,and the microstructure and hardness of the joints were analyzed. The results show that the surface morphology of the joints change significantly with varying the laser pulse current and width,and the penetration and width of the welds significantly increase with the increasing the welding heat input. The welding zone is mainly composed of austenite and a small amount of ferrite. There are mainly cellular grains in the weld center and columnar grains at the edge of the welding zone. Notably,the growth orientation of columnar grain is approximately perpendicular to the fusion line. The cross-section of the joint is similar with a'cup'shape and the distribution of hardness presents 'W'shape.