压缩螺旋弹簧的断裂分析

Fracture analysis of a compress spiral spring

通过观察断口的宏观痕迹、微观形态以及金相组织，并辅以测定表面宏观残余应力、硬度梯度等试验，对一动力机械上的圆柱形压缩螺旋弹簧的断裂原因进行了较为细致的分析．结果表明，此批弹簧断裂是由磨削加工不当在磨剂端面下亚表层产生了氢致沿晶开裂带，弹簧服役承载时在正应力的作用下发生了氢滞后脆性断裂．改进磨削工艺后弹簧脆断现象完全消除．

The fracture reason for a compress spiral spring with cylindrical shape working on a power machinery is analyzed by observing the macroscopic traces and micro morphology of the fracture and metallographic structure, combined with measuring the residual stress and hardness test. The results show that the fracture for the spring results from intergranular crack strips induced by hydrogen on the subsurface because of an inappropriate grinding machining. The results also show that the spring occurred brittle fracture arising from tensile stress. With an improvement of the grinding technology, the brittle fracture of the spring will disappear completely.