284-paper-低碳钢热轧产品氧化皮的原子力显微镜分析.docVIP

Oxide scale microstructure characteristics of hot-rolled low carbon steel by AFM Jian Li and Xinxing Xiao （RD Center, ） Atomic Force Microscopy (AFM) has been used to study the oxide scale profiles of hot-rolled low carbon steel. High-resolution images show clear double-layered structure of the scales by Magnetic Force Microscopy (MFM). X-ray diffraction (XRD) identified the phase composition of the scale. The most significant finding is that AFM can display image of the grain configuration of wustite. The mechanical properties and pickling periods of the scales depend strongly on the microstructure of the scales. Key words: AFM, hot-rolled, oxide scale 0. Introduction It is known that the oxide scale formed on rolling and rolled process in air comprises three layers, namely, a thin outermost layer of hematite (Fe2O3), an intermediate magnetite (Fe3O4) layer, and a thick inner wustite (FeO) layer. The intervals for oxidation of steel are from half a second to several minutes in a hot rolling process. The three-layered-structure is unstable at lower temperatures. During hot rolling of steel, the scales affect the frictional conditions which results in changes in the required roll forces, power consumption and surface quality. On the other hand, the scale can also influence the heat-transfer behaviour of the strip/wire. Moreover it can also influence the mechanical properties and the pickling time of scales, which affected greatly the succeeding manufacture process. Unfortunately, it is not easy to observe oxide scale behaviour directly under industrial working conditions, neither in laboratory. In order to evaluate the effect of the oxide scale for steel strip (wire), some previous researchers have analyzed the microstructure, as papers in [1-2]. The most commonly tools for studying microstructure of oxide scale are optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). As an emerging important tool for microstructure