Development of Higher Ductility and Lower Strain Aging Sensitivity X90/X100 Pipeline Steel

High grade pipeline steel which is based on multi-phase microstructure concept has excellent mechanical properties, such as large uniform elongation, low yield ratio and low strain aging sensitivity. The results of industrial trial show that the multi-phase X90/X100 pipeline plate steels and longitudinal submerge arc welded linepipe have excellent advantages of lower yield ratio, larger uniform elongation, and less fluctuation of both yield and tensile strength, and the X90/X100 pipes also have a lower strain aging sensitivity. The excellent mechanical properties of multiphase X90/X100 linepipe can meet the restrict requirement for the future more safety and high efficiency design and construction of pipeline project.