针对西气东输二线项目用厚规格X80钢板技术要求和沙钢炼钢、轧钢技术装备条件，采用低碳、高铌的HTP成分和OHTP（Optimized High Temperature Processing）控轧控冷工艺，进行了22 mm厚X80钢板批量生产和JCOE直缝焊管制管试验。结果表明，OHTP X80钢板无论力学性能、-15 ℃落锤性能，还是JCOE制管后管体屈强比均比HTP钢有明显改善。OHTP X80钢板-80 ℃下夏比冲击吸收能仍处于上平台,CVN值大于270 J，50％FATT低于-100 ℃，-30 ℃下DWTT落锤试验断口剪切面积的比例大于90％，85％DWTT为-34 ℃。

According to the technical requirements of X80 heavy thickness plates for the second westtoeast natural gas transmission pipeline project and the capability of steelmaking and plate mill of Shagang, a HTP chemical design of low carbon and high niobium was adopted and the OHTP of control rolling and cooling for plates was developed. A mass production of 22 mm thickness of X80 plate and manufacturing of LSAW JCOE pipes of 22 mm×1219 mm were carried out. The results show that the mechanical properties, DWTT properties at -15 ℃ of plates and the yield/tensile ratio of the pipes were significantly improved by comparing that of HTP X80 plates. The absorb energy of Charpy Vnotch impact test at -80 ℃ remains at its top platform above 270 J, the 50% FATT is below -100 ℃. At -30 ℃, the DWTT fracture shear area is 90％, and 85％ DWTT value is at -34 ℃.