主汽门操纵座弹簧的断裂失效分析

Failure Analysis of a Spring in Manipulating Pedestal of Main Throttle Valve in a Power Plant

对某电厂汽轮机主汽门操纵座弹簧的断裂失效进行了分析。结果表明:弹簧材料化学成分及组织都符合国家标准;导致其早期疲劳断裂的主要原因是弹簧表面的腐蚀坑;腐蚀坑是在弹簧使用前的放置过程中形成的;改善弹簧放置环境和缩短放置时间可以避免腐蚀坑的产生。

The fracture of a spring in manipulating pedestal of a main throttle valve used for steam turbine was studied. Both of composition and microstructure are qualified for the national criterion. The fracture mechanism of the spring is fatigue fracture. The main reason of the early fatigue fracture arose from the surface corrosion of the spring, which occurred during the placement before use. This problem cab be solved by improving the placement environment and shortening the placing time.