General technical requirements for pipeline steel
Modern pipeline steel is a low-carbon or ultra-low carbon micro-alloyed steel. It is a product with high technical content and high added value. The production of pipeline steel has applied almost all new technological achievements in the field of metallurgy in the past 20 years. The current development trends of pipeline engineering are large pipe diameters, high-pressure rich gas transportation in high-cold and corrosive service environments, and thick-walled submarine pipelines. Therefore, the current performance requirements for pipeline steel mainly include the following aspects:
(1) High strength. The strength indicators of pipeline steel mainly include tensile strength and yield strength. While requiring high strength, there are also requirements for the yield strength ratio (ratio of yield strength to tensile strength) of pipeline steel, which is generally required to be in the range of 0.85~0.93.
(2) High impact toughness. Pipeline steel requires materials with sufficiently high impact toughness (crack initiation and crack arrest toughness). For the base metal, when the toughness value of the material meets the requirements for crack arrest, its toughness can generally also meet the requirements for preventing crack initiation.
(3) Low ductile-brittle transition temperature. Harsh regional and climatic conditions require pipeline steel to have a sufficiently low ductile-brittle transition temperature. D state cut.
