采用火花直读光谱仪、布氏硬度计、扫描电镜和光学显微镜等对断裂45钢垃圾箱吊环的化学成分、硬度、断口形貌和显微组织进行了分析。结果表明: 吊环断裂为脆性断裂; 吊环的显微组织显示材料呈过热状态, 析出片状铁素体和粗大晶粒, 导致材料的冲击韧度下降, 是吊环脆性断裂失效的主要原因。

The chemical components, hardness, fractographs and microstructure of the fractured 45 steel suspension loop were analyzed by optical emission spectrometer, Brinell hardenss tester, scanning electron microscope and optical microscope. The results show that the fracture of the suspension loop was brittle fracture. Microstructure of the suspension loop was lamellate ferrite and coarsing grains, which show that the 45 steel was overheated and the impact toughness of it was decreased, and it was the main cause for brittle fracture of the suspension loop.