TMCP工艺对高性能桥梁钢Q370qE-HPS组织性能的影响研究

为了研究TMCP工艺对Q370q E-HPS高性能桥梁钢组织和性能的影响,达到替代正火工艺的目的,对终轧温度、开冷温度、返红温度及冷却速率等TMCP关键工艺参数与组织、力学性能的关系进行分析。结果表明:采用两阶段控轧控冷工艺生产Q370q E-HPS钢时,随终轧温度升高、开冷温度降低、返红温度升高及冷却速度降低,铁素体晶粒尺寸增大,珠光体含量增加,屈强比降低。通过工艺参数优化,可获得合适尺寸和体积分数的铁素体和珠光体,实现Q370q E-HPS钢良好的强韧性匹配和较低的屈强比。

The Effects of TMCP on Microstructure and Mechanical Properties of High Performance Bridge Steel Q370qE-HPS

In order to study the effects of TMCP on microstructure and mechanical properties of high performance bridge steel Q370qE-HPS and replace normalizing process during the production of the steel, the correlation between the key TMCP process parameters such as finish rolling temperature, start cooling temperature, re-tempering temperature , cooling rate and microstructure, mechanical properties are analyzed.The results show that with increasing finish rolling temperature, decreasing start cooling temperature, rising re-tempering temperature, lowering cooling rate, the ferrite grain size and pearlite constituent increase, yield and tensile ration decreases when producing Q370qE-HPS steel with II Phase controlled rolling and controlled cooling process.By optimizing process parameters, ferrite and pearlite of appropriate size and volume fraction can be maitained, which enables a good matching of strength and toughness and lower yield to tensile ration for Q370qE-HPS steel.