A105锻钢球阀激光深熔焊接工艺优化及组织性能研究

Study on Process Optimization and Microstructure and Properties of A105 Laser Welding

采用正交试验对5 mm厚A105锻钢管件激光深熔焊接工艺参数进行优化,确定了各工艺参数对各响应量的影响程度及最优焊接工艺,对该最优工艺参数下焊接接头组织和力学特性进行研究。结果表明:在激光功率2.0 kW,焊接速度7 mm/s,离焦量-1 mm,保护气体流量20 L/min焊接参数条件下焊接效果最好,可以实现5 mm厚A105锻钢的高速稳定激光对接自熔焊接,焊接接头成形良好;激光功率对各响应量的影响最大,熔深和抗拉强度随激光功率的增大而增加;焊缝区域(WZ)晶粒尺寸较小,焊缝金属主要由板条状马氏体构成,其硬度高于母材(BM);热影响区(HAZ)较窄,出现粗细晶粒分层现象;焊接接头硬度分布不均匀,在焊缝熔合区(FZ)有着最高硬度408.8 HV;焊缝的强度优于母材。

Orthogonal test on 5 mm thick A105 forged steel pipe fittings laser self-melting welding process parameters optimization,to determine the degree of influence of each process parameter on the response of the amount and the optimal welding process,the optimal process parameters under the organization of the welded joints and mechanical properties of the study.The results show that:under the conditions of laser power 2.0 kW,welding speed 7 mm/s,defocus-1 mm,shielding gas flow 20 L/min welding parameters,the welding effect is the best,and the high-speed and stable laser butt fusion welding of 5 mm thick A105 forged steel can be realized,and the welded joints are well shaped;the laser power has the greatest influence on the response quantities,and the depth of fusion and tensile strength increase with the increase of laser power;the weld zone(WZZ)and the weld area(WZZ)are the most affected by laser power,and the weld joint organization and mechanical properties are investigated.increase;the weld zone(WZ)grain size is smaller,the weld metal is mainly composed of lath martensite,and its hardness is higher than that of the base material(BM);the heat-affected zone(HAZ)is narrower,and there is a phenomenon of coarse and fine grain delamination;the hardness of the welded joints is not uniformly distributed,and there is a maximum hardness of 408.8 HV in the fusion zone(FZ)of the weld joints;and the strength of the weld joints is better than that of the base material.