1, stainless steel is deoxidized in smelting stage. First, manganese (electrolytic manganese sheet is 99.7%, which has the national standard) and ferrosilicon are used for primary deoxidization. The primary deoxidization can remove most oxygen in molten steel, for example, it can reach 70-90%, and the chief culprit of casting defect rate is often those "silent" and "stubborn" 65438+.
2. For those stubborn oxygen, the primary deoxidation process is powerless. Temperature and deoxidation ability determine that the primary deoxidizer completes the task, and the final deoxidation process completes this fatal blow to residual oxygen. The final deoxidizer is generally a so-called composite deoxidizer with two or more components. A large number of practices show that when the compound deoxidizer containing many elements enters the molten steel, it not only plays its own role in coordination, but also is congested with each other. Compared with fighting alone, it can significantly increase its own deoxygenation efficiency. Therefore, this idea of 1+ 1=3 is a very important design factor when designing composite deoxidizer products. Of course, there are other important indexes of compound deoxidizer, which seem insignificant and actually indispensable.