露点对DP590双相钢表面氧化行为的影响

DP590双相钢在连续退火过程中不可避免地发生合金元素氧化现象,使用扫描电镜(SEM)、X射线能谱仪(EDS)、X射线光电子能谱仪(XPS)以及辉光放电光谱仪(GDS)对在不同露点温度下进行退火处理的DP590钢进行表征分析。结果表明:在退火过程中,随着露点温度的升高,DP590钢由外氧化转变为内氧化,钢板表面氧化程度呈现先增大后减小的趋势,数值模拟结果指出DP590钢内外氧化临界转变露点为-8.26 ℃,与试验结果相符合。DP590钢表面氧化物以锰的氧化物为主,随着露点温度的升高,Mn元素和O元素在DP590钢表面的富集峰值变化表现为先增大后减小,Si元素和Al元素的富集峰值则呈现逐渐降低趋势。XPS数据显示钢板表面形成的氧化物主要以MnO、Mn-Si-O氧化物和Si-O氧化物的形式存在。

Effect of dew point on surface oxidation behavior of DP590 dual phase steel

Oxidation of alloy elements is inevitable in continuous annealing process of the DP590 duplex steel. The DP590 steel after annealing at different dew points was characterized and analyzed by means of scanning electron microscope (SEM), X-ray energy spectrometer (EDS), glow discharge spectrometer (GDS), and X-ray photoelectron spectrometer (XPS). The results show that during annealing process, as the dew point temperature increases, the DP590 steel changes from external oxidation to internal oxidation, the oxidation degree of the steel plate surface shows a trend of first increasing and then decreasing. The numerical simulation results indicate that the critical transition dew point of internal and external oxidation of the DP590 steel is -8.26 ℃, which is consistent with the test results. The surface oxide of the DP590 steel is mainly manganese oxide. With the increase of dew point temperature, the enrichment peaks of Mn and O elements on the surface of DP590 steel increase first and then decrease, while that of Si and Al elements show a gradually decreasing trend. The XPS data show that the oxides formed on the surface of DP590 steel mainly exist in the form of MnO, Mn-Si-O oxide and Si-O oxide.