一例紧固螺栓断裂失效的组织分析  

Fracture Failure Analysis for a Fastening Bolt

作　　者：韩锋[1] 张晓义[1] 李旋[1] 

机构地区：[1]北京北冶功能材料有限公司,北京100192

出　　处：《金属材料研究》2013年第2期41-45,共5页Research on Metallic Materials

摘　　要：真空感应熔炼炉炉体上盖紧固螺栓在使用过程中发生断裂。经观察发现螺栓的底座和螺杆分别由两种材料jj^-c而成，通过压焊的方式焊接在一起。由于受焊接时的短时高温的热应力冲击作用，工件的结合处出现过热的组织变化，底座出现了严重的魏氏组织；螺杆的晶粒异常粗大。“过热”产生的粗大晶粒和严重的魏氏组织使材料的力学性能恶化，疲劳极限和塑性显著下降，特别是室温下的冲击韧性明显下降。导致工件无法承受正常的载荷而发生断裂。Vacuum induction melting furnace body superstructure fastening bolt breakage during use, by observation found that the base of the bolt and screw, respectively, from two materials processed, are welded together by pressure welding. Overheat morphology due to transient high temperature welding, the combination of the workpiece at the base appeared serious widmanstatten structure; screw the abnormal grain coarsening. ＂Overheating＂ coarse grain and serious widmanstatten structure, deterioration of the mechanical properties of the material, a significant decrease in fatigue limit and plasticity, especially at room temperature impact toughness decreased. The workpiece would be broken under normal load.

关 键 词：断裂 焊接 过热 魏氏组织 晶粒粗大 

分 类 号：TG142.73[一般工业技术—材料科学与工程]