液压脉动去除护环锻件宏观残余应力

护环是大型汽轮发电机的关键件,其中存在很高的宏观残余应力。护环的宏观残余应力不允许用回火方法去除,高的回火温度会损失护环的力学性能指标。用脉动抽压调整护环宏观残余应力是一个行之有效的办法,既可去除宏观残余应力,又可使护环的力学性能不受损失。 把护环密封进行16次注高压油脉动实验,油压接近100MPa。实验结束后,用切应力环的办法测量宏观残余应力,用大千分尺测量护环环口直径的变化。发现经16次打压后,护环宏观残余应力下降50％,而护环环口尺寸也发生明显改变,最大变化量为3mm,护环的尺寸得以稳定。 介绍了油压脉动去除宏观残余应力的方法,并且提出了“双动力”原理解释去除宏观残余应力的新机制。

To Relieve the Macro Residual Stress in Retaining Ring by Hydraulic Pressure Pulsation Method

Retaining ring is a very important part of heavy steam turbine generator. There is a high macro residual stress in retaining ring. The macro residual stress tempering isn't permitted. because tem-pering at high temperature will damage the mechanical properties of retaining ring. So we have to invent a new method for relieving the macro residual stress in retaining ring. Hydraulic pressure pulsation method is an effective method for relieving the macro residual stress in retaining ring. It doesn't damage the mechanical properties of retaining ring.