柔性轧制Q390C和Q420C钢板生产实践

目前市场对中厚板的订单具有个性化和多样化的特点，而对于不同强度级别的钢板，化学成分设计往往是不同的，这样会增加不同钢坯冶炼之间衔接的时间及化学成分控制的难度，导致冶炼成本增加，工序复杂化。结合市场需求与生产实际，采用同一Q390低合金高强度钢板坯，通过不同的控轧控冷工艺，对Q390C和Q420C两种强度级别热轧钢板进行了试制。结果表明，通过控轧控冷技术，可以充分发挥细晶强化作用，采用同一Q390低合金高强度钢板坯实现了Q390C和Q420C两个强度级别热轧钢板的柔性生产。试制生产的两种钢板，强塑性及0 ℃冲击功均满足标准要求，Q420C钢板屈服强度达441 MPa以上，抗拉强度达579 MPa以上。采用柔性轧制技术，降低了Q420C高强钢板的生产成本。

Production practice of flexible rolling technology for Q390C and Q420C plates

At present,the market orders for medium and heavy plates are personalized and diversified.For plates of different strength levels,the chemical composition design is often different,which will increase the connection time between different steel making, the difficulty of chemical composition control, and increase smelting costs and complicate processes.Combined with market demand and production reality,the same Q390 low alloy high strength steel slab was used,and through different controlled rolling and cooling processes,the hot rolled plates of two strength levels of Q390C and Q420C were trial produced.The results show that through the controlled rolling and controlled cooling technology,the fine grain strengthening can be fully exerted.The same Q390 low alloy high strength steel slab is used to achieve the flexible production for two strength levels of Q390C and Q420C plate.The strength,plasticity and impact energy at 0 ℃ of produced plates meet the standard requirements.The yield strength of Q420C plate is more than 441 MPa and the tensile strength is more than 579 MPa.The production cost of Q420C high strength plate is reduced by flexible rolling technology.