Brief introduction of the whole process of pickling of packaging steel strip

Brief introduction of the whole process of pickling of packaging steel strip
　　Hot-rolled coils are cold-rolled billets, because the final rolling temperature of hot-rolled coils is about 800℃ or higher, so iron scale is formed on the surface. One of the purposes of cold-rolled strip steel is to obtain good surface properties. Therefore, the iron oxide scale must be removed before cold rolling. This is the first purpose of the pickling operation. The tasks completed by the pickling can be summarized as follows:
　　 1. Remove surface oxide scale
　　 There are physical (mechanical) methods and chemical methods to remove surface oxide scale. For the treatment of cold-rolled billets, chemical methods that can increase the surface properties are generally used, that is, pickling is used. The most used acids are hydrochloric acid and sulfuric acid. Recently, most of the hydrochloric acid line is used, which has a short processing time and good quality. There are also two methods in which the chemical method is the main method and the physical method is supplemented.
　　2, the coil is enlarged
　　 In order to increase the operation rate and increase the yield rate in the next process, history has effectively used the storage space of the factory and used 2-3 hot-rolled coils to be welded together to increase the cold-rolled coils. The welding machine generally adopts a flash butt welding machine with a short operating time and a firm welding part.
　　3. Oiling
　　The purpose of oiling is to prevent rust, to prevent scratches and to provide auxiliary lubrication during rolling, and to pre-coat a layer of oil on the pickled steel strip.
　　4. Disc type edge trimming machine (edge u200bu200btrimming)
　　 According to the requirements of the order, the width of the strip is cut, and in order to avoid rolling accidents caused by the change of the width of the hot-rolled coil, the edge is cut.
　　5. Management of properties of hot-rolled coils
　　 The inspection of the properties (surface defects, plate shape, coil shape, etc.) of hot-rolled coils is to improve the quality of raw materials, and then improve the quality of finished products.
　　The pickling line is located between the hot rolling process and the cold rolling process. In terms of mutual quality management, it can be said to be a very important line.