针对某厂生产的10B21钢螺纹轴出现延迟断裂现象, 利用直读光谱仪、光学显微镜、维氏硬度计、扫描电子显微镜等分析了其断裂原因。结果表明: 该轴表面硬度过高, 且在其表面渗碳、酸洗等生产工艺中引入了有害氢未能及时去除, 螺纹根部在螺纹段预紧力、齿根应力及局部氢原子富集的协同作用下发生了氢致延迟脆性断裂。

Aimed at the delayed fracture effect of 10B21 steel threaded shaft produced by the plant, the fracture reason was analyzed by means of optical emission spectrometer, optical microscope, Vickers hardness tester and scanning electron microscope. The results show that the surface hardness of the shaft was too high and the harmful hydrogen introduced by the process of surface carburizing and pickling was not eliminated in time, resulting in the hydrogen ductile-brittle fracture of the thread root under the synergistic effect of the screw pretention, thread root stress and local enrichment of hydrogen.