电流对ZL114A补焊工艺孔组织及力学性能的影响

Effect of Welding Current on Microstructure and Mechanical Properties of ZL114A Repair Welding Process Holes

利用光学显微镜、扫描电子显微镜、拉伸实验机等设备分别对200A、240A和280A3种不同焊接电流补焊ZL114A合金工艺孔的组织及力学性能进行了研究。实验结果表明,在热影响区随着电流强度的增加,其宽度增加,但晶粒尺寸基本不变,而在熔凝区随着电流强度的增加晶粒尺寸明显增加;在240A时,熔凝区形成的气孔数量最少,并且热影响区中共晶相分布均匀,硬度最高。拉伸实验表明,不同电流强度补焊的ZL114A工艺孔拉伸试样断裂位置均发生在热影响区,但在电流强度为240A时,补焊后的力学性能最接近母材,抗拉强度达到了母材强度的95.0%,所以240A为ZL114A工艺孔最佳补焊电流。

The effects of welding currents of 200 A,240A and 280 A on microstructure and mechanical properties of ZL114 A alloy repair welding process holes were investigated using optical and scanning electronic microscope（ SEM）,tensile testing machine,respectively. With the increase of current intensity,the heat affected zones widen and grain size almost unchanges,but the grain size increases apparently in fusion zone. At 240 A,the amount of pore is the least at fusion zone,and the eutectic phases distribute uniformly in heat affected zone,the hardness reaches the maximum value. The results of tensile test show that the fracture of tensile samples all locate in heat affected zone. At 240 A,the sample tensile strength is closest to that of the base metal,and reaches ninetyfive percent of the base metal tensile strength. So the optimized repair welding current is 240 A.