Production process of stainless steel

First, stainless steel crude steel smelting process
At present, the smelting process of stainless steel production in the world is mainly divided into one-step, two-step and three-step methods, as well as new integrated production methods. One-step smelting is: molten iron + AOD (argon oxygen refining furnace); The two-step method is: EAF (electric arc furnace) + AOD (argon oxygen refining furnace). The three-step method is: EAF (Electric Arc Furnace) + AOD (Argon Oxygen Refinery) + VOD (Vacuum Refinery). In addition to several traditional production processes, the current integrated production process, that is, the production process from molten iron directly to stainless steel, has also been adopted by many enterprises, and the production process is: RKEF (rotary kiln electric furnace) + AOD (argon oxygen refining furnace).

Second, stainless steel hot rolling process
The hot rolling process of stainless steel is made of slab (mainly continuous casting billet) as raw material, and after heating, strip is made from roughing mill and finishing mill. The hot steel strip from the last rolling mill of finishing rolling is cooled to the set temperature by laminar flow, and is rolled into a steel coil by the coiling machine, and the cooled steel coil has oxide scale on the outside, showing black, commonly known as "stainless steel black leather coil". After annealing and pickling, the oxidized surface is removed, that is, "stainless steel white skin roll", and most of the hot-rolled products circulating in the stainless steel market are stainless steel white skin roll. The specific stainless steel hot rolling production process is as follows:

Third, stainless steel cold rolling process
After stainless steel hot rolling, some stainless steel hot rolled products are directly used downstream, and some hot rolled products need to continue to be processed into cold rolled before use.

Stainless steel cold rolling, mostly using hot rolled stainless steel hot rolled products with a thickness of 3.0-5.5mm, after the calendering processing of cold rolling equipment, produced into stainless steel cold rolled products. At present, the main production process of stainless steel cold rolling is two categories: stainless steel single-frame cold rolling and stainless steel multi-frame cold rolling. The specific production process is as follows:

After the stainless steel is cold-rolled, it needs to go through annealing and pickling units. Annealing of cold-rolled stainless steel is achieved by eliminating work hardening through the process of recrystallization to achieve the purpose of softening; The purpose of pickling is to remove the oxide layer formed on the surface of the steel strip during the annealing process, and the second is to passivate the surface of the stainless steel to improve the corrosion resistance of the steel plate.