二次冷轧基板的特性及其对镀铬铁表面形貌的影响

Characteristics of double-reduced black plate and its influence on surface morphology of chromium coating electroplated on it

采用扫描电镜和电化学分析方法研究了不同轧辊使用阶段所生产的二次冷轧基板的特性及其对镀铬铁表面形貌的影响。结果表明,二次冷轧基板表面的轧制纹可以明显地呈现在镀铬铁表面:在轧辊使用初期,二次冷轧基板表面存在较多细小的轧制纹,导致镀铬铁表面镀层存在较多针孔;在轧辊使用中期,二次冷轧基板表面轧制纹均匀,所得镀铬铁表面形貌较好;在轧辊使用后期,二次冷轧基板表面出现破损。在相同清洗条件下,乳化液或轧制油易残留在二次冷轧基板表面的细小轧制纹中,而在轧制纹均匀的表面则易被清除,因此,轧辊使用初期生产的二次冷轧基板在碱洗前后的自腐蚀电位和容抗弧半径差值较小,而对于轧制纹相对均匀的轧辊中期、中后期或后期生产的基板,其差异较大。

The characteristic of double-reduced black plate produced in different roller using stages and its influence on the surface morphology of chromium-plated iron plate were studied by scanning electron microscopy and electrochemical analysis method. The results indicated that the rolling lines on the surface of double-reduced black plate can clearly appear on the surface of chromium-plated iron plate. At the early stage of use of roller, there are many fine and small lines existing on the surface of double-reduced black plate leading to many pinholes on the surface of chromium-plated iron plate; at mid-stage, the rolling lines on the surface of black plate are uniform and the surface morphology of the obtained chromium-plated iron plate is good; at later stage, the surface of substrate is damaged. Under the same rinsing conditions, the emulsion and rolling oil used are easily remained in fine and small lines on surface of double-reduced black plate, but it is eliminated easily from the surface of uniform rolling lines. Therefore, the differences between corrosion potentials and between radii of capacitive impedance arc of double-reduced black plate produced at early stage of use of roller before and after alkaline rinsing are small, while the differences of which produced at middle-stage and middle-to-late stage as well as later stage with relatively uniform rolling lines are large.