脱硫电机轴失效分析

Failure Analysis on Desulfurization Motor Shaft

某电厂脱硫电机轴材料为17CrNiMo6钢,在使用中断裂。对断裂的电机轴进行了宏观检查、金相检验、断口分析和拉伸试验。结果表明:脱硫电机轴键槽根部的倒角半径仅为0.1 mm,远小于要求的0.4~0.6 mm,加剧了该部位的应力集中,导致脱硫电机轴运行中在交变弯曲应力和扭转应力的作用下发生疲劳断裂。

A desulfurization motor shaft,made of 17 CrNiMo6 steel,broke in service in a power plant.The broken motor shaft was subjected to macro-check,metallographic examination,fracture test and tensile test.The results showed that chamfering radius of keyway root of the desulfurization motor shaft was as little as 0.1 mm which was significantly less than desirable 0.4 to o.6 mm,and rendered stress concentration more intense at this position,thus resulting in fatigue failure of the desulfurization motor shaft under the action of alternating bending and torsion stresses in operating.