闪光焊FeCrAl合金管材的接头组织及性能

Microstructure and property of flash welded joint of FeCrAl alloy tube

采用闪光焊对FeCrAl合金进行对接接头焊接,通过扫描电子显微镜及能谱仪等手段研究了焊接接头的显微组织特征、不同区域氧化物颗粒的分布情况及力学性能.结果表明,闪光焊焊接FeCrAl合金所得焊接接头显微组织主要为等轴晶,在焊缝和热影响区氧化物未出现明显聚集及向晶界偏聚的现象,且在晶内和晶界都可以呈现弥散分布的特征;焊接接头抗拉强度值达到594 MPa,为母材强度的90.5%;接头断裂在焊缝区,整体呈现脆性断裂模式;焊缝晶粒的粗化导致焊缝区硬度降低,最终引起焊接接头出现软化.

The butt joints of FeCrAl alloy were welded by flash light welding. The microstructure, distribution of oxide particles and mechanical properties of the welded joints were investigated by scanning electron microscope and energy dispersive spectrometer. The results show that: the microstructure of FeCrAl alloy welded by flash light welding is mainly equiaxed grain. No obvious oxides are aggregated and segregated in the grain boundary of weld metal and heat-affected zone. Most oxides are dispersed in the grain and grain boundary. The tensile strength of the welded joint reaches 594 MPa,which is 90.5% of the strength of the base metal. The joint is fractured in the weld zone and presents the brittle fracture mode as a whole. The grain coarsening of the weld metal makes the hardness decrease, which leads to the softening of the welded joint.