露点对预氧化还原QP钢表面选择性氧化的影响  

Effect of dew point on the selective oxidation of oxidized-reduced QP steel sheet

作　　者：汤文杰[1] 金鑫焱[2,3] 胡广魁 TANG Wenjie;JIN Xinyan;HU Guangkui(Cold Rolling Plant,Baoshan Iron&Steel Co.,Ltd.,Shanghai 200941,China;Research Institute,Baoshan Iron&Steel Co.,Ltd.,Shanghai 201999,China;State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel),Shanghai 201999,China)

机构地区：[1]宝山钢铁股份有限公司冷轧厂,上海200941 [2]宝山钢铁股份有限公司中央研究院,上海201999 [3]汽车用钢开发与应用技术国家重点实验室(宝钢),上海201999

出　　处：《宝钢技术》2021年第2期1-9,共9页Baosteel Technology

摘　　要：以0.2%C-1.8%Si-1.8%Mn成分的QP钢为研究对象,采用预氧化还原模拟试验,在露点分别为-40℃和+10℃的N_(2)-5%(体积分数)H_(2)气氛中制备了预氧化还原试样,使用GD-OES分析了表层5μm深度范围Fe、Si、Mn、O的元素深度分布,使用SEM观察了表面形貌,使用TEM观察了FIB制备的截面试样微观形貌。结果表明:预氧化试样表面氧化铁/基板界面位置已存在Si、Mn富集,经过还原退火后,还原铁/基板界面位置的Si、Mn富集进一步增加。提高退火气氛露点促进了Si、Mn在钢板次表层形成内氧化;减少了还原铁/基板界面位置的Si、Mn外氧化;改变了还原铁/基板界面位置的氧化物组成和结构,由Si-O和Mn-Si-O的双层结构变为Mn-Si-Fe-O复合氧化物结构。Oxidation-reduction experiments were conducted on 0.2%C-1.8%Si-1.8%Mn QP steel and the effect of dew point on the selective oxidation of oxidized-reduced QP steel sheet was investigated.Oxidized samples were reduced in N_(2)-5%(vol)H_(2)atmosphere with dew point of-40℃and+10℃,respectively.GD-OES was used to measure the elemental depth profiles of Fe,Si,Mn and O in the depth range of 0-5μm.The surface morphologies were observed by SEM,and the cross-section morphologies of the FIB prepared specimens were observed by TEM.It was found that a thin layer of Si and Mn oxides already occupied the scale/substrate interface in oxidation step and was enhanced in reduction step.With the increasing of dew point from-40℃to+10℃,the internal oxidation of Si and Mn in the subsurface was increased,and the external oxidation of Si and Mn at the reduced iron/substrate interface was decreased.Both the composition and microstructure of the external oxides at the reduced iron/substrate interface were determined by dew point.A two-layer oxides composed of Si-O and Mn-Si-O were changed to Mn-Si-Fe-O complex oxides.

关 键 词：QP钢 预氧化还原 露点 选择性氧化 

分 类 号：TG142.1+2[一般工业技术—材料科学与工程]