Prodroduction Technology of X80 Pipeline Steel on 2250 Hot Strip Rolling Line in Lianyuan Steel

摘要

2250 hot strip rolling line is one of the most widely hot mills in China.The article introduces composition design and process control of X80 pipeline steel produced by 2250 hot strip rolling production line.Mechanical properties,Microstructure and precipitation behavior of X80 pipeline steel were studied.The results indicate that X80 pipeline steel with a thickness of 18.4mm produced by 2250 hot strip rolling line shows excellent mechanical properties,with an average yield strength of 655MPa and an average tensile strength of 750MPa.The average impact energy is 300J at -20℃,while the average percentage of DWTT shear area is 95％.It is observed that the microstructure of X80 pipeline steel mainly consists of granular bainite and acicular ferrite.The precipitation distributes homogeneously,with an average length of 20nm.