新型高强度管线钢控轧控冷工艺及其组织性能研究

Thermo-mechanical Control Process of Novel High Strength Pipeline Steel and Its Microstructure and Properties

通过合理的组织、成分设计,在实验室成功试制新型高强度管线钢.对控轧控冷工艺参数中加热温度,终轧温度,终冷温度,冷却速度设计四要素三水平正交实验,应用Gleeble-3500热模拟实验机模拟控轧控冷工艺,得到的最佳工艺参数组合进行实验室轧制实验.利用金相显微镜对模拟和实验室轧制试样进行金相组织分析,并进行力学性能检测.结果表明,加热温度1180℃,终轧温度810℃,终冷温度400℃,冷却速度35℃/s时,钢板可获得粒状贝氏体,针状铁素体,下贝氏体,M/A的最佳组织构成与最优的综合力学性能.

In order to meet the requirements of pipe steel used in the oil industry with higher strength,toughness and corrosion resistance,the chemical composition of a novel high strength pipeline steel was designed. By using the Gleeble-3500 thermomechanical simmulator,the parameters of thermo-mechanical control process,including heating temperature,final rolling temperature,final cooling temperature and cooling rate,were tested by the orthogonal experiments with four factors and three levels,then the optimum parameters obtained were used in the rolling experiments conducted in the prototype rolling line. The microstructure and mechanical properties of the steel were studied. The results showed that the microstructure of the specimen rolled under the optimum parameters mainly consisted of the granular bainite,acicular ferrite and lower bainite. The mechanical properties reached the expected standard of novel pipeline steel when it was heated at 1180℃,rolled at 810℃,and finally cooled at 400℃ at the cooling rate of 35℃/s.