Research On The Corrosion Resistance Of Pure Magnesim Sheets Produced By Rolling

Under the theme of environment protection,as the representative of the lightweight metal, magnesiμm(Mg) and its alloys have been widely used in the areas of military industries and civil products for its good comprehensive performance. Magnesiμm(Mg)has gained great attention in the biomedical field too, because of its non-toxic and the characteristic of the Young’s modulus is close to the bones of hμman body. Therefore,magnesiμm has great market potential in the biomedical field.In this paper, certain thickness of pure magnesiμm was prepared by cross rolling(including cold rolling and hot rolling) and normal rolling(including cold rolling and hot rolling). The optimal scheme of pure magnesiμm plate process was obtained by comparing microstructure and the properties of these sheets to select. These sheets’ corrosion resistance and the corrosion mechanism was analyzed by means of electrochemical experiments(Tafel curves and AC impedance spectroscopy) and immersion test to in artificial simulated body fluid.In order to obtain the 2 mm sheets, we took two steps, first: we used φ18mm rod to get the 5 mm thick plates through four times rolling. second: on the basis of 5 mm thick plates, we got the final 2 mm thick sheet by cross rolling(including cold rolling and hot rolling) and normal rolling(including cold rolling and hot rolling). The results are lists as follows by analyzing the microstructure and the properties of these sheets: Compared to the normal rolling, cross rolling can, to a certain extent, decrease the anisotropic. In the same way of rolling conditions, compared with hot rolling, cold rolling can significantly reduce the grain size, so that they can increase mechanical properties of the sheet to a great extent, especially the elongation. So under this experimental condition, from the perspective of decreasing anisotropy and increasing the elongation,cross cold rolling is optimal.The effects of grain boundary, twin and texture on corrosion resistance were discussed by analyzing these 5 mm thick plates. By means of electrochemical test and immersion experiment,we can draw the conclusion that the main corrosion type is pitting corrosion, For the present investigation conditions, the smaller the grain size, the higher the content of grain boundary, and the faster the corrosion rate, The higher the content of twin, the faster the corrosion rate. The texture types of these final sheets are basal texture. This texture type can, to a certain extent, increase the corrosion resistance of the sheets. Considering all these factors, we can get final corrosion law of these sheets:The corrosion rate of normal cold rolled sheet is faster than that of the normal hot rolled sheet,in the same way, the corrosion rate of cross cold rolled sheet is fasterthan that of the cross hot rolled sheet, the corrosion rate of the cross rolled sheet is faster than that of the normal rolled sheet.