LNG用9Ni钢控轧控冷工艺的热模拟研究

Study on Thermal Simulation of Controlled Rolling and Cooling of 9Ni Steel Used in LNG

采用Gleeble 3800热模拟实验机测定了9N i钢的CCT曲线,进行不同终轧温度变形试验,分析了不同冷却速度对组织的影响,研究了不同终轧温度与组织、晶粒度、性能的关系。结果表明：轧后冷却速度大于5℃/s为马氏体组织,小于3℃/s为贝氏体组织,9N i钢的终轧温度选择800~850℃,晶粒细小,综合力学性能良好。

CCT curves of 9Ni steel was tested by using the thermodynamic simulator Gleeble 3800,different finishing temperature after final deformation tests were experimented,different cooling rate on microstructure were analysed,the relations between different final deformation temperature and microstructure,grain size,performance were researched.The results show that martensite is available when cooling rate over 5 ℃/s or more after rolling,bainite is available less than 3 ℃/s,finishing rolling temperature′s scope keeps 800~850 ℃ is appropriate,the grain size is fine,the comprehensive mechanical properties of steel achieved good.