Development of High Performance Pipeline Steel

The development of high performance pipeline steel in recent years in the world is reviewed. The modern high performance pipeline steel has been developing for high strength, heavy wall, high deformability and HIC-resistance. For the investment reduction of long distance natural gas pipeline project, the X100 and X120 grades ultra-high strength pipeline steels were developed and the demonstration pipeline lines of X100 and X120 were successfully constructed. Based on “strain-based design”, high deformability grade X65-X100 high strength pipeline steel with dual-phase microstructure were developed, which can be laid in seismic region, cold region and soil and water loss region. The steel grade for offshore pipeline and HIC-resistance pipeline has been stepped from X65 to X70, and the X70 pipes with a wall thickness up to 34 mm have been applied in offshore pipeline project. The new ultra-low carbon, high niobium and chromium high strength pipeline steel X80 produced by HTP has high performance and lower cost by using chromium instead of molybdenum which were used in the X80 pipeline project in USA.