国产核电用大直径P91无缝钢管的研发

Development of Large-sized P91 Seamless Steel Pipe Used for Domestic Nuclear Power Plant

介绍了国产核电用大直径P91无缝钢管的制造工艺及产品性能。通过控制管坯加热温度避免δ铁素体组织的产生,设计优化热轧成型工艺,采用大变形二辊斜轧穿孔、均整精轧及在线定径的一火成材工艺,合理设计热处理制度及模拟焊后热处理温度等控制措施,开发生产出第四代核电主蒸汽管道用大直径P91无缝钢管。经过对钢管头、中、尾分别取样进行试验评定,结果显示,该P91无缝钢管性能良好、金相组织均匀、稳定,不仅具有良好的高温持久性能,而且还具有优异的低温冲击韧性,交货状态和模拟焊后热处理状态下各项性能均满足ASME核电标准和600 MW示范快堆工程主蒸汽管道系统用SA-335 P91无缝钢管的技术协议要求。利用等温线外推法,计算出交货状态500℃10万小时下的高温持久强度为228 MPa,模拟焊后热处理状态下500℃10万小时下的高温持久强度为224 MPa,两者均满足核电ASME第Ⅲ卷D5 Table HBB-I-14.6F考核强度(212 MPa)的要求,产品已应用于第四代核电核岛主蒸汽管道项目。

The manufacturing process and the product performance of the large-sized P91 seamless steel pipe as used for domestic nuclear power plant are described in this paper.By controlling the heating temperature of the pipe billet to avoid the formation of 5 ferrite structure,optimizing the forming process of hot rolling,using large deformation two-roll diagonal rolling,uniform finishing rolling and on-line sizing one-fire forming process,rationally designing the heat treatment system and simulating the heat treatment temperature after welding,the large diameter P91 seamless steel pipe for the main steam pipe of the fourth generation nuclear power plant was developed and produced.After testing and evaluation by sampling the head middle and tail of the steel tube,the result is displayed,the P91 steel pipe has uniform and stable performance and microstructure,not only has excellent hi-temperature creep rupture property,but also has excellent low temperature impact toughness.All the properties meet the requirements of ASME nuclear power standard and technical agreement requirements of SA-335 P91 seamless steel pipe for the main steam piping system of 600 MW commercial fast reactor project,the high temperature lasting strength is 228 MPa under the condition of delivery at 500°C for 100,000 hours,and 224 MPa under the condition of simulated post-welding heat treatment,both of which meet the requirements of the inspection strength(212 MPa)of ASME Section Hi D5 Table HBB-I-14.6F,the product have been used for the main steam pipeline of the nuclear island of the fourth generation nuclear power plant.