Q390C高强结构钢热轧板的开发及工艺优化

Development and Process Optimization of Q390C High Strength Structural Steel Hot-rolled Plate

在Q345C钢的基础上,通过成分设计和控轧控冷(TMCP)工艺优化,开发出一种新型高强结构钢Q390C。采用Gleeble-3500热模拟机测定了Q390C钢的CCT曲线,研究了它的高温热塑性,分析工艺对室温组织的影响规律,以及终冷温度与屈强比之间的关系。二阶段控轧控冷制工艺参数为:粗轧开轧温度1020~1150℃,二次开轧温度920~940℃,终轧温度820~850℃,终冷温度660~680℃,矫直离线后堆冷冷速1~2℃/s,最终产品厚度控制在15~30 mm。通过生产过程控制与优化,Q390C高强结构钢热轧板各项性能指标符合技术要求。

On the basis of Q345C steel, a new type of high strength structural steel-Q390C was developed through composition design and thermo mechanical control process （TMCP） process optimization. CCT curves of Q390C steel were measured by Gleeble-3500 thermal simulation machine. The high temperature thermoplastic was studied, and the effect of controlled roiling and cooling process on microstructure at room temperature, and the relationship between the final cooling temperature and the yield ratio were analyzed. Two stage controlled rolling and controlled cooling process parameters are as follows ：the initial rough rolling temperature is 1020-1150 ℃, the second start rolling temperature is 920-940 ℃, the finish rolling temperature is 820-850℃, the final cooling temperature is 660-680 ℃, and the cooling rate of stack cooling after straightening offline is 1-2 ℃/s. The thickness of final product is controlled between 15 to 30 mm. Through the production process control and optimization, the performance index of hot rolled plate of Q390C high strength structural steel meets the technical requirements.