stainless steel production process

The term stainless steel refers not only to one type of stainless steel, but to more than 100 industrial stainless steels, each of which performs well in its specific field of application. The key to success is to first understand the purpose and then to determine the correct steel grade. There are usually only six steel grades related to building construction applications, and they all contain 17 to 22% chromium, and the better grades also contain nickel. The addition of molybdenum can further improve atmospheric corrosion, especially the corrosion resistance of Cl-containing atmosphere.

     Stainless steel is often divided into: martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the structure state. In addition, it can be divided into: chromium Stainless steel, chromium-nickel stainless steel and chromium-manganese-nitrogen stainless steel, etc.

Stainless steel production mainly includes crude steel smelting, hot rolling, cold rolling and other links:

1. Stainless steel crude steel smelting process

At present, the smelting process for producing stainless steel in the world is mainly divided into one-step method, two-step method and three-step method, as well as new integrated production methods. The 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 refining furnace) + VOD (vacuum refining furnace). In addition to several traditional production processes, the current integrated production process, that is, the production process from molten iron to stainless steel, has also been adopted by many enterprises. The production process is: RKEF (Rotary Kiln Electric Furnace) + AOD (Argon Oxygen Refining Furnace).

Second, stainless steel hot rolling process

The stainless steel hot rolling process uses slabs (mainly continuous casting slabs) as raw materials, and after heating, strips are made by rough rolling mills and finishing mills. The hot steel strip coming out of the last rolling mill of finishing rolling is cooled to the set temperature by laminar flow, and is rolled into a steel coil by a coiler. . After annealing and pickling, the oxidized surface is removed, which is called "stainless steel white coil". Most of the hot-rolled products circulating in the stainless steel market are stainless steel white coils.

Three, stainless steel cold rolling process

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

For cold-rolled stainless steel, stainless steel hot-rolled products with a thickness of 3.0-5.5mm are mostly used. After being rolled by cold-rolling equipment, cold-rolled stainless steel products are produced. At present, the main production processes of stainless steel cold rolling are two types: stainless steel single-stand cold rolling and stainless steel multi-stand cold rolling.