冷轧双相钢表面氧化色形成机理与控制措施

冷轧双相钢氧化色与钢种内部Mn元素的选择性氧化现象相伴而生,氧化色严重的带钢表现出不同的电化学特性,耐蚀性较差。Mn元素的选择性氧化与闪冷段冷却风机位置氧含量密切相关,带钢出水淬槽后水的轻微残留更容易加速腐蚀反应从而加重氧化色。通过炉区退火模拟实验,验证氧含量对带钢表面状态的影响。氧含量较高时,可在带钢表面发现明显的氧化物颗粒。采用高H2冷却模式可以提高混合气体换热系数,减小冷却风机与带钢距离可明显降低冷却风机功率,减轻Mn元素在带钢表面的氧化富集,配合优化淬水槽挤干效果,可良好解决带钢表面氧化色问题。

Mechanism and control measures of surface oxidation color on the cold-rolled dual-phase steel

The oxidation color of cold rolled dual-phase steel was always in accompany with the selective oxidation behavior of the manganese element in the steel.The strip steel with different oxidation color showed different electrochemical characteristics,and the corrosion resistance was poor.The selective oxidation behavior of manganese had strong relationship with the oxygen content in the flash cooling section of the annealing furnace.The residual water on the strip after the water quenching tank could accelerate the corrosion process which deteriorated the oxidation color.Annealing simulation experiment was carried out to research the effect of the oxygen content on the state of the strip surface.Oxide particles on the surface of the strip can be found when the oxygen content is high.Using high hydrogen content mode in the flash cooling section can increase the heat transfer coefficient and smaller distance between the injector and the strip can reduce the the power of the cooling fans and the selective oxidation behavior of manganese by high oxygen content can be reduced.With the optimization of quench tank squeezing effect,the oxidation color of the cold-rolled dual-phase steel can be effectively eliminated.