通过QC活动提高800MPa级钢岔管洞内焊缝一次探伤合格率

Improvement of grade 800MPa steel bifurcated pipe tunnel weld primary flaw detection qualification rate through QC activity

江苏溧阳抽水蓄能电站钢岔管为目前国内抽水蓄能电站中体型最大的钢岔管,也是首例800MPa级钢材在洞内原位组装、焊接、水压试验项目。在解决3号大岔洞内焊接施工焊缝一次探伤合格率偏低问题过程中,通过QC活动,找出产生质量问题的具体原因;在1号大岔管洞内焊接施工中,寻找出切实可行整改方法,成功提高了岔管洞内焊缝探伤一次合格率。经专家咨询会论证,1号大岔通过加强施工过程质量控制,免做水压试验,为同行业类似工程施工提供了借鉴依据和参考经验。

Jiangsu Liyang pumped storage power plant steel bifurcation pipe has the maximum body type in domestic pumped storage power stations at present.It is also the first case of grade800MPa steel materials in tunnel insitu assembly,welding and hydraulic test projects.When the problem of low primary flaw detection qualification rate of No.3big bifurcation tunnel welding construction welds is solved,concrete reasons of quality problems are discovered through QC activities.Solutions are adopted in a targeted mode during No.1big bifurcation tunnel welding construction.Actual and feasible improvement methods are discovered for successfully improving primary flaw detection qualification rate of bifurcated pipe tunnel welds.Water pressure test is avoided in the No1big bifurcation through strengthening quality control in the construction process according to demonstration of expert consultion conference,thereby providing reference basis and reference experience for construction similar projects in the same industry.