Packaging steel strip manufacturer: production process of cold rolled strip steel

Packaging steel strip manufacturer: production process of cold rolled strip steel
　　 The most general technological process for cold-rolled strip production; centered on the cold strip mill, from hot-rolled coils to continuous pickling, cold rolling (strip cold rolling mill), electrolytic cleaning, annealing, and temper rolling System-finishing (cutting line, rewinding line) and other operations.
　　1. Continuous pickling
　　Continuous pickling is a process in which hot-rolled coils are continuously passed through a hydrochloric acid tip or a sulfuric acid tank to remove the scale on the surface. In addition, in order to improve the operation rate and yield of the subsequent process, several hot-rolled sheet coils are welded together and rolled into a large coil.
　　2. Cold rolled
　　The cold rolling mill is an equipment that milks hot-rolled coils to the thickness of the finished product at room temperature. Rolling oil is used as a lubricant between the roll and the strip, and as a coolant for the roll. Usually four-high multi-stand continuous cold rolling (tandem mill) and single-stand reversing mill are used for cold rolling. The former is used for high-efficiency and high-yield varieties; the latter has low productivity and is suitable for multiple varieties and special materials.
　　3. Electrolytic cleaning
　　Electrolytic cleaning is a process to remove the rolling oil remaining on the surface of the cold-rolled steel sheet. In the process of the strip passing through the electrolytic cell continuously, electrolytic cleaning is used to degrease.
　　4. Annealing
　　Because the crystal structure after cold rolling has high hardness and poor workability, it is necessary to recrystallize through annealing process to improve its crystal structure. Annealing is one of the processes that greatly affects the performance of cold-rolled strip steel. According to the specifications and uses of the finished product, the annealing method (tight coil, loose coil) and annealing system (annealing temperature, annealing time, heating rate, etc.) are determined.
　　5. Smooth rolling
　　 Lightly cold-roll the annealed steel strip to eliminate the yield platform while improving the flatness of the finished product and controlling the surface finish. These are the purposes of leveling. The leveling mill adopts 1-2 four-high rolling mills, and the reduction rate is usually about 1%.