摘要
Abstract
In view of the characteristics of the main steam super pipeline in nuclear power plants,such as large wall thick-ness,deep and narrow groove,large welding deposition volume and high inspection requirements,the difficulties of on-site installation welding construction were analyzed,and quality control measures were proposed from four aspects:welding pro-cess control,welder skill management,operating environment control,and post-weld treatment and inspection control.For welding process control,a slender nozzle was adopted for GTAW root pass with proper manipulation and shielding,and a re-served window was used to monitor the back-side formation of the weld.For welder skill management,welder qualification screening,primary qualification rate assessment,specialized training and performance-based incentive were implemented to ensure the welders'skill level.For operating environment control,wind shielding and dehumidification measures were strengthened.For post-weld treatment,post-heating and stress relief heat treatment processes were strictly controlled,and non-destructive testing was added before heat treatment for early defect identification.With the above control measures,the primary qualification rate of on-site installation welding for the main steam super pipeline in a nuclear power plant reached 100%,which can provide reference for quality control of on-site installation welding of similar thick-walled pipelines.关键词
核电站/主蒸汽超级管道/安装焊接/质量控制/氩电联焊Key words
nuclear power plant/main steam super pipeline/installation welding/quality control/GTAW+SMAW分类
矿业与冶金
