The Production of Cold Rolling Imprint and Elimination Measures
Cold rolled steel plate is a common material in the construction industry, and it is widely used. In the process of cold rolling, there will inevitably be some kneading fault ribbon lines produced. From the appearance of the profile, it is a shallow groove line, which is produced by cold rolling. So what is the cause of cold rolling imprint and how to prevent it?
Cold rolling imprint is a type of material defect caused by improper operation during the cold rolling process. In the forming process, due to the defective structure formed by the roller groove, the material is subject to an additional compressive force, causing the material to be trapped and making the material wrinkle and circular imprint. Its forming principle is a combination of plastic deformation and residual stress caused by the work roll system. The contact area increases during the forming process, which causes local plastic deformation to occur and lead to scratches on the surface of the steel plate. Additionally, when some steel plate materials with poor compression performance are used, the contact area will become larger and the friction force between the steel plate and the reverse roll system will increase, leading to wrinkles and circular imprint on the surface of the steel plate.
The prevention of cold rolling imprint should start with improving the quality of the rolling stock. The surface of the round steel should be flat and free of dents, so that when it is rolled, the metal material will not be prematurely broken and therefore will not cause imprints. Moreover, pay attention to the temperature of the round steel when rolling to ensure it is suitable. Too low a temperature will make the steel brittle, making it more prone to imprint, while too high a temperature will cause a large amount of plastic deformation, making the steel plate thinner and easier to break, leading to circular and other marks. At the same time, attention should also be paid to reducing the contact pressure and degree of deformation during the rolling process. Reduced amounts of deformation and pressure will lead to fewer cold rolling presses.
In addition to optimizing the process, measuring instruments can also be used to detect the cold rolling imprint. At present, the commonly used method is optical microscopy mainly used to observe and analyze the punched marks and the circular imprint on the surface of the steel plate. The advantage of using this method is that it is convenient, fast and has high accuracy. The operator can easily find the deepest part of the circular imprint, which can clearly reflect the forming quality of the steel plate. However, this method also has a certain detection limit, so it cannot be used for the detection of small circular imprints or those with a shallow depth.
If there are already circular imprints, it is necessary to eliminate them. The most common method is mechanical polishing. This method involves the use of a special polishing wheel with a grit of 1500-2000 to remove the circular imprint. This method is mainly used when the mark is not too deep and not spread over a large area. If it is a deeper or large surface circular imprint, chemical pickling or electrolytic cleaning can be used to effectively remove it. The advantage of this method is that even a deep circular embossed mark can be effectively removed, saving a lot of processing time and the cost is also relatively low.
To sum up, cold rolling imprint is a common defect of the cold rolled steel plate in the production process. Its elimination measures include improving the quality of the rolling stock, optimizing the process, using measuring instruments to detect, and adopting chemical or mechanical methods for elimination.
参考翻译：
冷轧压痕的产生及措施消除
冷轧钢板是建筑行业中常见的材料，广泛使用。在冷轧过程中，不可避免地会产生一些揉合故障缎带线。从轮廓外观上看，是浅槽线，这是由冷轧造成的。那么，冷轧压痕的原因是什么，如何防止它呢？
冷轧压痕是由冷轧过程中不当操作而产生的一种材料缺陷。在成形过程中，由于辊槽形成的缺陷结构，使材料受到额外的压缩力，导致材料被陷入，使材料出现皱纹和圆形压痕。其形成原理是塑性变形和工作辊系统引起的残余应力相结合。在成形过程中，接触面积会增加，从而导致局部塑性变形发生，从而在钢板表面产生划痕。此外，当使用具有较差压缩性能的一些钢板材料时，接触面积会变大，猛钢板与反辊系统之间的摩擦力会增加，从而导致钢板表面出现皱纹和圆形凹痕。
防止冷轧压痕应从改善轧制原料的质量开始。圆钢的表面应平整无凹陷，这样在轧制时，金属材料就不会提前断裂，从而不会造成压痕。而且，还要注意圆钢在轧制时的温度，确保温度合适。温度过低会使钢变脆，易产生压痕，而温度过高使钢板形变量大，使钢板变薄，更容易断裂，导致出现圆形及其他痕迹。同时，还要注意在轧制过程中减少接触压力和变形度，减小变形压力量会减少冷轧压痕。
除优化工艺外，还可以使用测量仪器来检测冷轧压痕。目前，常用的方法是光学显微镜，主要是用来观察分析钢板表面的压痕和圆形压痕。该方法的优点是便捷、快速、精度高，操作者可以轻松发现圆形压痕最深处，可以清楚反映钢板
