Surface Color Difference Causes of Reaming Steel after Pickling

Color difference defects appeared on the surface of reaming steel HR440/580HE after pickling. The causes of color difference were analyzed by means of chemical composition analysis, microscopic analysis and energy spectrum analysis. The results show that the color difference of the hot rolled plate was due to the diffuse reflection of visible light caused by the distribution of local cluster scale. The more cluster scale, the more serious the diffuse reflection, resulted in the difference of reflection. The visual sense was a banded color difference with different color depths. The residual iron olivine scale on the surface of the hot rolled plate was more difficult to remove than ordinary scale, resulted in different pickling effects and color difference on the surface of pickling plate.