薄板坯连铸连轧过程中氧化铁皮变化规律

来源期刊：钢铁2011年第6期

论文作者：吴光亮 孟征兵 李一为 成小军

文章页码：79 - 85

关键词：薄板坯连铸连轧； 氧化铁皮； 薄板连铸坯； 热轧板卷

Key words：thin slab continuous casting and rolling； scale； continuously-cast sheet slab； hot rolled sheet and coil

摘    要：研究了采用薄板坯连铸连轧生产DC04热轧板卷过程中氧化铁皮的变化规律。以采集连铸坯均热前后铸坯上、下表面及热轧板卷附着的氧化铁皮作为试验材料,利用M21X超大功率X射线衍射仪对氧化铁皮的形貌及氧化铁皮粉末XRD物相进行了分析。其结果表明:铸坯进均热炉前,氧化铁皮较薄为100μm,铸坯经过均热炉加热后,氧化铁皮增厚到200~300μm。与氧化铁皮-基体界面比较,氧化铁皮的气体-氧化铁皮界面具有较多的孔洞,甚至裂缝,结构很疏松;氧化铁皮XRD定性分析表明,铸坯入炉前后、上下表面氧化铁皮均含有Fe₃O₄、Fe₂O₃和FeO共3种物相。SEM分析表明,在线热取样和冷取样下,热轧板氧化铁皮与基体之间因体积效应产生的内应力而形成了裂缝,铁皮结构呈现出疏松、多孔特点,有利于带钢表面酸洗。热取样氧化铁皮厚度比冷取样氧化铁皮厚度薄,冷卷尾样铁皮比冷卷头样厚。热取样氧化铁皮厚度与热轧板厚度成正比例关系。卷取温度在600~680℃范围内,热取样氧化铁皮厚度、物相相对含量变化不明显。

Abstract: The variation of scale during thin slab continuous casting and rolling was studied.Hereinafter are the results of analyses on scale characteristics of pre-and post-soaking DC04 thin slab as well as HR coils.Firstly,the scale is 100 μm thick before the slab is charged into soaking furnace,and it turns to be 200-300 μm thick after the slab is heated by the furnace.Secondly,compared to the interface between scale and base material,there are many pores,even cracks and loose structure between scale gas and scale.The XRD analysis on the scale shows that,the scales on both top and bottom surfaces all have Fe₃O₄,Fe₂O₃ and FeO when the slab is charged or discharged.Thirdly,the SEM analysis shows that,cracks occur between scale and base material due to internal stress by volume effect,despite HR sheet sample taken hot or cold.Also,the scale structure is featured as porous and loose,which helps the pickling of strip surface.Fourthly,the scale of hot sample is thinner than that of cold sample,and that from tail of CR coil is thicker than that from head.And,the thickness of hot sample scale is directly proportional to that of HR sheet.With coiling temperature at 600-680℃,there is no significant variation in thickness of hot sample scale and relative contents of phases.