焦雄 邓朝 董团伟

摘要：随着国产高强钢生产和高强钢焊接等关键技术的突破，并在国内大型水电工程成功应用，显示出了高强钢蜗壳管壁厚度薄，具有良好的低温冲击韧性的优点，但是高强钢碳当量大，对延迟裂纹敏感性较强，选择与其母材化学成分、力学性能相匹配的焊材和操作性强的焊接工艺参数尤为关键，在现场焊接过程中焊接质量很难控制，在高温、高湿的地下电站厂房中施工具有很大的挑战。该文以乌东德右岸地下电站800MPa级高强钢蜗壳焊接为例，分别从高强钢材料选用、焊接工艺选定、焊接过程控制3个方面进行分析论述，实践证明：国产800MPa级钢材质量可靠，制定焊接工艺可操作性强，焊缝焊接质量优良，保证了蜗壳高强度、良好的冲击韧性。可为其他大型水电站高强钢蜗壳施工提供了重要的参考和借鉴价值。

关键词：乌东德 高强钢 焊接技术 工艺参数 质量优良

Application of Domestic 800mpa High Strength Steel and Welding Technology in Power Station

JIAO Xiong1DENG Zhao2DONG Tuanwei1

（1. Hanjiang-to-Weihe River Valley Water Diversion Project Construction Co.， Ltd.， Xi’an， Shanxi Province， 710010 China; 2.China Three Gorges Construction Management Co.， Ltd，Chengdu， Sichuan Province， 610094 China）

Abstract： With the breakthrough of key technologies such as domestic high-strength steel production and high-strength steel welding， and the successful application in domestic large-scale hydropower projects， it shows that the wall thickness of high-strength steel spiral case is thin and has the advantages of good low-temperature impact toughness.But the carbon equivalent of high strength steel is large and the sensitivity to delayed crack is strong. It is particularly critical to select welding materials that match the chemical composition and mechanical properties of the base metal and welding process parameters with strong operability. It is difficult to control the welding quality in the on-site welding process， and it is a great challenge in the construction of underground power plant under high temperature and humidity. Taking the welding of 800MPa high strength steel volute of Wudongde right bank underground power station as an example， this paper analyzes and discusses the selection of high strength steel materials， welding process selection and welding process control respectively. The practice shows that the quality of domestic 800MPa steel is reliable， the welding process is operable， and the welding quality is excellent， which ensures the high strength and good impact toughness of spiral case. It can provide important reference and reference value for the construction of high-strength steel spiral case in other large hydropower stations.

Key Words： Wudongde power station; High strength steel; Welding technology;Processing parameters; Good quality

1工程概況

金沙江乌东德水电站是金沙江下游河段四座水电站（乌东德、白鹤滩、溪洛渡、向家坝）中最上游的梯级电站，左右岸地下电站各安装6台单机容量85万kW水轮发电机组，总装机容量1020万kW，多年平均发电量389.1亿kW·h，正常蓄水位975.0m，总库容74.3亿m。

乌东德水电站右岸地下电站安装的6台单机容量为85万kW的水轮机蜗壳由30个管节组成，总重约685t，通过补偿节与对应的6条压力钢管相连接，蜗壳进口直径为11.5m，除过渡段采用600MPa级高强度钢板制造外，其余部位全部采用国产800MPa级低碳高强……