Grinding 8K surface is not up to standard/Customers are using stainless steel 0.75*515mm cold rolled coil, grinding 8K surface in deep processing, during the grinding process, because the surface can not achieve 8K effect, file a quality objection complaint to the steel mill. Judging from the cold-rolled substrates on site, there were slight iron oxide scale indentations and scratches on the surface to varying degrees. Upon inspection, the batch of steel coils were sold as black coils, and then flowed into the market after being pickled by local soil. Observation of the 2K cold-rolled surface after 8K grinding from the site. The 8K grinding process with nitric acid and iron oxide red has a relatively low grinding cost. Generally, the mirror effect can be achieved after one pass of processing. For the surface of the coil, communicate with the user: 1. Hot rolling and cold rolling are two different rolling technologies. Hot rolling is the rapid rolling of the billet after heating at high temperature. The cold rolling is to roll the hot rolled NO.1 coil as the raw material at normal temperature, and different rolling processes obtain different strip surface and geometric dimensions. The surface quality, appearance, and dimensional accuracy of cold-rolled strip are better than those of hot-rolled strip, and deep-processing of products is carried out by using cold-rolled steel coils as the substrate to become high-value-added products. 2. For the cold-rolled surface obtained by grinding 8K by hot rolling, if it is the hot-rolled NO.1 coil pickled by the steel mill, not all the plates can achieve the effect of grinding 8K obtained by cold rolling. At present, the ratio of cold-rolled strip steel to 8K grinding of major steel mills on the market is obtained to verify the description. 3. There are higher requirements for grinding 8K cold-rolled sheet surface: the surface of the substrate must not have defects such as rust stains, chatter marks, trachoma, roller marks, scratches, scrapes, creases, peeling, etc. However, secondary quality defects occur in every processing procedure of the product, such as peeling of the surface of the hot rolled NO.1 coil. Vibration marks, roll marks, and scratches are generated during cold rolling and annealing, and improper adjustment of the strip heads of different thicknesses during grinding or foreign objects on the pinch rolls can also cause surface quality problems. Due to the existence of different defects on the surface of the steel strip, it is difficult to eliminate the defects through grinding the surface through grinding or increasing the number of grinding passes. 4. Therefore, customers are purchasing cold-rolled coils as substrates for grinding 8K surfaces or purchasing hot-rolled NO.1 and entrusting cold-rolling and rolling processing. They must have sufficient thought and psychological preparation. If the 8K surface effect is not achieved, the product can be changed to a matte surface. Sales. Rather than grinding to achieve a surface effect of 8K, a quality claim is filed with the steel mill. The steel mill does not accept the complaint about the quality objection and recommends that it be sold as a variety of surfaces such as frosted. As a marketer, you need to understand the needs of end customers, understand the characteristics of different stainless steel products, understand the advantages and disadvantages of stainless steel products in each process, and improve the quality of your business to introduce clear product quality to customers before they can obtain customer Trust and admire.