细晶高强钢S420M的开发生产实践

Development and Production Practice of Fine Grain High Strength Steel S420M

在S420M细晶高强钢开发中采用低C和Nb、Ti微合金化成分设计,选择LD转炉冶炼→LF炉精炼→RH真空精炼→连铸→控轧控冷工艺流程。通过对控轧控冷工艺进行优化调整,生产钢板的组织晶粒尺寸达3~7μm,综合性能良好,屈服强度、抗拉强度、延伸率和低温冲击韧性均远高于用户需求,满足供货技术条件的要求。

In the development of S420M fine grain high strength steel,the composition design of low carbon content,Nb and Ti microalloying is used,the process flow route of LD converter melting,LF refining,RH vacuum refining,continuous casting,controlled rolling and controlled cooling is selected.By optimizing and adjusting the controlled rolling and controlled cooling process,the grain size of the produced steel plate microstructure ranges from 3μm to 7μm with good comprehensive properties.The yield strength,tensile strength,elongation ratio and low temperature impact toughness are all higher than the customers’requirement,satisfy the requirements in supply technical specification.