1.Crude stainless 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 method is: molten iron + AOD; the two-step method is: EAF + AOD. The three-step method is: EAF+AOD+ VOD. 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 companies. The production process is:RKEF+AOD.