某电厂汽轮机高调阀座合金裂纹分析与处理

Analysis and Treatment of Alloy Crack of High Pressure Regulating Valve Seat in a Power Plant

某电厂2号机组高压调节汽阀十字头改造期间,1号高压调节汽阀阀座司太立合金堆焊部位发现3处裂纹、1处脱落。经检验分析,高压调节汽阀阀座司太立合金堆焊部位裂纹是由于熔合线区域应力集中,在长期负荷波动较大的工况运行条件下发生的。文章对汽轮机高压调节汽阀阀座司太立合金裂纹原因进行了分析,对施工方案的选择进行了论证,并提出了预防措施,经过长期运行后,没有出现阀座密封面裂纹、脱落等类似现象。

During the transformation of the crosshead of the high pressure regulating valve of Unit 2 in a power plant,three cracks and one fall-off were found in the stellite alloy surfacing part of the valve seat of No.1 high pressure regulating valve.According to the inspection and analysis,the cracks occur under the operating conditions of long-term load fluctuation due to the stress concentration in the fusion line area.This paper analyzes the causes of cracks on the valve seat of steam turbine,verifies the construction plan and puts forward preventive measures.No similar problems occur afterward in a long period of operation.