The pickling coil is made of high-quality hot-rolled sheet as raw material, and the oxide layer is removed by the pickling unit, trimmed, and finished. The intermediate product between the plates is an ideal substitute for some hot-rolled and cold-rolled plates. Compared with hot-rolled sheets, the advantages of pickling coils are: 1. Good surface quality, because hot-rolled pickling sheets remove the surface iron oxide scale, improve the surface quality of steel, and facilitate welding, oiling and painting. 2. High dimensional accuracy, after flattening, the plate shape can be changed to a certain extent, thereby reducing the deviation of unevenness. 3. Improve the surface finish and enhance the appearance effect. 4. It can reduce the environmental pollution caused by users' dispersed pickling. Compared with cold-rolled sheet, the advantage of pickling sheet is that it can effectively reduce the purchase cost of users under the premise of ensuring the surface quality and use requirements. Many enterprises put forward higher and higher requirements for high performance and low cost of steel. With the continuous advancement of steel rolling technology, the performance of hot-rolled sheet is approaching that of cold-rolled sheet, so that "replacing cooling with heat" can be technically realized.