在线淬火中厚板表面氧化铁皮的控制与改善

钢板表面的氧化铁皮不仅影响产品外观质量，在轧制和矫直过程中还会导致氧化皮压入缺陷。采用控制轧制和直接淬火（DQ）工艺，研究了不同的淬火温度与终冷温度对低合金高强钢板表面氧化铁皮的影响，分析了钢板表面氧化铁皮结构及其脆化的原因。试验表明，通过增加除鳞道次并不能有效改善氧化铁皮，精轧轧制温度与轧后加速冷却过程对氧化铁皮结构具有显著影响，高冷速条件下通过降低精轧轧制温度与淬火温度，能够得到以FeO为主要成分的氧化铁皮，其具有良好的塑性并且分布均匀，避免了淬火后强力热矫直时氧化铁皮破碎并压入基体的问题，钢板抛丸后表面光洁。

Control and improvement of oxide scale on the surface of heavy and medium plate by direct quenching

The oxide scale on the surface of the plate not only affects the appearance of the product,but also leads to the oxide scale indent defect during rolling and levelling.The structure and cause of embrittlement of the oxide scale on the surface of low alloy high strength plate under direct quenching (DQ) condition were analyzed.The effects of different quenching temperature and final cooling temperature on surface oxide scale were investigated.The results show that the scale can not be effectively improved by increasing the descaling pass.The structure of oxide scale was significantly affected by finishing rolling temperature and accelerated cooling process after rolling.The FeO based oxide scale can be obtained by reducing the finishing rolling and quenching temperatures at high cooling rate,and it has good plasticity and evenly distributed on the plate surface.After shot blasting,the surface of plate was smoothing,which avoided the problem of oxide scale fragmentation and pressing into the matrix during hot levelling process with large levelling force after direct quenching.