冷轧薄板表面色差原因分析

利用共聚焦显微镜对冷轧薄板的色差表面形貌进行观察,发现条状色差主要是由于带钢表面粗糙度不均匀引起。通过生产现场调研发现,在焊缝连接处色差纹路具有连续性特征,且通过轧机急停取样后发现色差主要是由于连轧机的5#机架引起。分析表明,带钢粗糙度不均与轧制过程中乳化液油膜在工作辊面分布不均相关,而油膜不均与乳化液的喷射方式、轧制速度、乳化液的颗粒度和接触角存在直接关系。通过增加乳化液辅助喷嘴,控制轧制速度,并将轧制油的颗粒度由13μm降低至8μm,油滴接触角由80°降低至63°,色差缺陷得到解决。

Analysis on reasons of surface chromatism for cold.rolled thin sheet

The surface chromatism of cold.rolled thin sheet was observed by real color confocal scanning microscope, and the non.uniform roughness on the surface of sheet resulted in linear chromatism.The texture of chromatism was featured by continuity in the welding zone between two coils.And it is found that the chromatism is caused by the fifth stand of the tandem cold rolling mill after taking samples during emergent braking.The analysis result indicates that the non.uniform roughness of sheet correlates to the uneven distribution of emulsion oil film, which relates to spray method of emulsion, rolling speed, and granularity and contact angle of oil droplets during the cold rolling process.Thus, the rolling speed is controlled by adding auxiliary spray nozzles of emulsion, and the granularity of oil droplets decreases from 13 μm to 8 μm as well as the contract angle of oil droplets decreases from 80° to 63°.Thus, the problem of chromatism is resolved.