This Stainless Steel 321 Wires must be absolutely clean and free from all oil, paint, grease, and shop soil when charged into the furnace. The furnace atmosphere for forging or open annealing in our Stainless Steel 321 Wire should be slightly reducing, containing at least 2 % of carbon monoxide. A slight positive pressure should be maintained in the furnace of this Stainless Steel 321 Coil Wire to prevent air infiltration. When our Stainless Steel 321 Wire is heated in a reducing atmosphere, a thin, adherent green – black film of oxide will be left on the surface of the material. In heating for hot working, this Stainless Steel 321 Wire should be brought up to temperature, allowed to soak a short time to ensure uniformity, and withdrawn. In oxidizing atmospheres of our Stainless Steel 321 Wires , a heavy black scale is produced that is very difficult to remove. Every precaution should be taken in heating this 321 Stainless Steel Wire so that only the green – black film is formed. There is excellent resistance in our 321 Stainless Steel Wire, which is similar to that of other nickel – chromium alloys, is a function of its composition.