针对生产过程中一批23MnNiMoCr54圆环用钢经闪光对焊后焊缝发生低应力断裂的问题,利用扫描电镜和能谱仪对焊缝的断口形貌及微观成分进行了分析。结果表明:在焊缝区域内存在着局部未熔区以及铸造疏松组织和二次裂纹等缺陷,这是导致试样低应力断裂的根本原因。 Aiming at the problem of low stress fracture of a series of 23MnNiMoCr54 ring steel after flash butt welding in the production process, the fracture morphology and microstructure of the weld were analyzed by SEM and EDS. The results show that there are some defects in the weld zone, such as local unmelted zone, as well as the loose structure and the secondary cracks in the casting, which are the basic causes of the low stress fracture of the specimen.