电焊机2024，Vol.54Issue(4)：63-70,8.DOI:10.7512/j.issn.1001-2303.2024.04.09
核电机组主蒸汽安全阀阀瓣密封面堆焊层开裂原因分析及预防措施
Cause and prevention measures for Cracking of Surfacing Layer on Sealing Surface of Main Steam Safety Valve Disc in Nuclear Power Units
汤恒 1银帮耀 1王琪 1邓江勇1
作者信息
- 1. 广西防城港核电有限公司,广西 防城港 538001
- 折叠
摘要
Abstract
During the overhaul of a certain nuclear power plant,the VVP116VV safety valve was disassembled and in-spected,and it was found that there were more than 20 crack defects in the welding layer on the sealing surface of the valve disc.Analyze the reasons for the cracking of the valve disc sealing surface surfacing layer through methods such as macro-scopic examination,chemical composition analysis,metallographic examination,hardness testing,residual stress analysis,scanning electron microscopy fracture analysis,and energy spectrum analysis.The results indicate that there is a problem of high dilution rate in the surfacing layer of the valve disc sealing surface.Analysis suggests that it is related to improper con-trol of the surfacing process(excessive welding heat input,improper heat treatment control).The main reason for the crack-ing of the surfacing layer is the high residual stress in the surfacing layer caused by excessive welding heat input.Improper control of interlayer temperature during the welding process and insufficient post weld heat treatment may be contributing factors to the cracking of the surfacing layer.According to the result of cause analysis,the disposal suggestions are given to provide reference for similar problems of other units.关键词
核电机组/主蒸汽安全阀/密封面/钴基堆焊/Stellite21合金/开裂Key words
nuclear power units/main steam safety valve/sealing surface/cobalt based surfacing/stellite21 alloy/cracking分类
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汤恒,银帮耀,王琪,邓江勇..核电机组主蒸汽安全阀阀瓣密封面堆焊层开裂原因分析及预防措施[J].电焊机,2024,54(4):63-70,8.
