Q550高强钢的冷却工艺和组织性能研究

Q550高强钢广泛应用于各类工程机械,其轧制工艺窗口窄,力学性能对轧制工艺非常敏感.为了优化实际生产的轧制工艺参数,本研究设定了3种工艺,通过调整Q550高强钢轧制过程和冷却过程的工艺参数,共得到了3种不同室温组织,对比其室温拉伸、弯曲、-20℃冲击性能检验结果发现,与铁素体+珠光体混合组织相比,上贝氏体组织提高了屈服...

Study on cooling process and microstructure of Q550 high strength steel

Q550 high strength steel is widely used in the construction machinery. However, the rolling process of Q550 high strength steel is relatively limited by the deformation and its mechanical properties are quite sensitive to rolling parameters. In order to optimize the rolling parameters for industrial production, three processes were designed by adjusting the parameters of rolling process and cooling process of Q550 high strength steel. Three different room temperature structures were obtained. By comparing the results of room temperature tensile and bending tests as well as the impact properties at -20℃, it was found that compared with those of the ferrite+pearlite mixed structure, the yield strength and tensile strength were improved by the upper bainite structure, but elongation was significantly reduced. For the granular bainite structure, improved strength and plasticity were increased and the impact toughness was significantly improved. Therefore, the comprehensive property of strength and toughness of the room temperature granular bainite structure was the best. This research laid a good foundation for further improvement of Q550 production rolling process.