【作者】 刘芳；

【导师】 李玉平； 韩培德；

【作者基本信息】 太原理工大学 ， 材料科学与工程， 2014， 硕士

【摘要】 不锈钢因其良好的机械性能和极高的耐腐蚀性被广泛应用于建筑业、工业等许多领域,但热轧过程中不锈钢因高温氧化表面极易生成一层致密的、连续的、与基体牢固结合的结构比较复杂的氧化皮。如果酸洗不彻底氧化皮极易被压入不锈钢,氧化皮的存在不但影响不锈钢制品的外观质量和使用性能,而且影响不锈钢工件的后续加工,甚至会造成不锈钢表面耐蚀性降低。本文针对酸洗剂中Cl-浓度对热轧430、443铁素体不锈钢酸洗表面质量的影响展开研究,采用金相显微镜、扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)、辉光放电光谱仪(GDS)等检测手段系统分析了热轧430、443铁素体不锈钢板材经不同C1-浓度的酸洗剂酸洗后表面氧化皮的组成、结构。为了弄清楚热轧430、443不锈钢板材酸洗表面对钝化处理后不锈钢板表面钝化膜组成的影响,本文对钝化处理后430、443铁素体不锈钢试样表面钝化膜的组成、成分也进行了分析。酸洗剂中Cl-浓度对热轧430铁素体不锈钢酸洗表面氧化皮分析结果表明：C1-浓度对430不锈钢表面氧化皮的去除影响显著；本实验条件下,当Cl-浓度较高(配方Cmg/1)时,可较为彻底去除与430不锈钢表面牢固结合的致密氧化物；对应于该试验条件下钝化处理后所获得的热轧板表面钝化膜分析表明,Cl-含量也会影响到钝化处理后430不锈钢表面钝化膜的质量,当Cl-浓度为配方Cmg/l时,430热轧板表面钝化膜Fe/Cr比低且致密度高。C1-浓度为配方Cmg/1时对热轧443铁素体不锈钢酸洗表面氧化皮结构和组成的分析结果表明：该Cl-浓度下经酸洗的443不锈钢表面中尚有微量断续的残留致密氧化物存在,这些氧化物以铬类型氧化物为主,表明443不锈钢表面氧化皮较430不锈钢更难以去除；对应于该条件下所获得的热轧板表面钝化膜来看,430不锈钢表面钝化膜的Fe/Cr比较低,为致密的铬氧化物。更多还原

【Abstract】 Stainless steels are used extensively in many fields such as building and manufacturing etc. for their good mechanical properties and high corrosion resistance. However, it is easy to produce continuous, compact and adherent complex oxide scale structure on the surface of stainless steel due to high-temperature oxidation during hot-rolling processing. The residual oxide scale will be pressed into the surface, which not only affects the appearance quality and properties of parts but also influences the subsequent processes of stainless steel and accelerates the corrosion of stainless steel.This paper researched compositions and structures of the oxide scale of hot-rolled430and443ferritic stainless steels on the pickling process by the different concentrations of Cl-. Metallographic microscope, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and glow discharge spectrum (GDS) were employed to analyze these characteristics. Moreover, the compositions and structures of passive film formed on the surface of the hot-rolled430and443ferritic stainless steels were analyzed in order to find out compositions of passive film.Effect of concentrations of Cl-on the pickling process for the oxide scale of hot-rolled430ferritic stainless steel was analyzed. The results indicated that the concentrations of Cl-in pickling agent significantly impact the removal of oxide scale. When the concentration of Cl-is Cmg/l, the oxide scale which is strongly adherent to the underlying metal can be more fully removed. The concentrations of Cl-also influence the quality of the passive film. A dense and corrosion resistant passive film on the hot-rolled430stainless steel can be generated by pickling process with above-mentioned concentration of Cl-.The compositions and structures of the oxide scale of hot-rolled430and443ferritic stainless steels on the pickling process were analyzed. The results showed that there is trace amounts of discontinuous residual oxide in the443stainless steel matrix and oxide interface which mainly is Cr oxides when the concentration of Cl-is Cmg/1. It was turned out that the oxide sclale of the hot-rolled443stainless steel which is strongly adherent to the underlying metal is more difficult removed than the oxide scale of the430stainless steel. A dense and corrosion resistant passive film which is Cr oxides on the430stainless steel can be generated by pickling process with above-mentioned concentration of Cl-.更多还原