导叶裂纹原因分析及处理方法

天生桥二级电站3号水轮发电机组在首次扩修过后的第一次小修中发现4号、15号导叶裂纹,经过处理后,在接下来的第二次小修中,又发现4号、15号导叶出现裂纹,同时新增了12号导叶裂纹。除15号导叶有一条裂纹为上一次焊缝裂纹外,4号1、5号导叶的其他裂纹为新增裂纹,针对这一情况进行分析和处理。

There are some cracks found on No. 4 and No. 15 guide blades in the first routine repair after the extension of No. 3 water- turbine generator set for the first time in Tian Shengqiao Second Hydroelectric Power Plant, then after the treatment, there are still some cracks found on No. 4 and No, 15 guide blades and new cracks found on No. 12 guide blade during the second routine repair. Except that a crack on No, 15 guide blade is the previous weld crack, other cracks on No. 4 and No. 15 guide blades are the new one. So the analysis and treatment is carried out for this situation.