关键词: 汽轮机, 低压缸, 大气释放阀, 爆破片, 铅板

Abstract: Data information is collected on the failure characteristics of abnormal rupture of the rupture disc of low-pressure(LP) cylinder release valve. In combination with the working conditions of LP cylinder, the macro crack analysis, microscopic fracture analysis and material composition analysis are conducted. Meanwhile, the mechanical performance test, metallurgical test and blast simulation test are also carried out. The results demonstrate that the crack of the lead-made rupture disc shall be categorized as fatigue fracture, resulting from the creep sensitivity of pure lead material. Therefore, suggestions such as shortening the replacing time interval of the rupture disc are put forward.

Key words: steam turbine, low-pressure cylinder, release valve, rupture disc, lead plate