Metal and atmospheric oxygen of
321 stainless steel seamless pipe in response to the appearance will constitute an oxide film. However, in the general carbon steel pipe on the composition of the continuous oxidation of iron oxide, so that corrosion continues to expand, resulting in holes. So that good stainless steel seamless pipe is damaged, we can use paint or oxidation of metal such as zinc, nickel and chromium plating to cover the appearance of carbon steel, but, as we expected, this maintenance only is a layer of maintenance film, assuming that the maintenance layer is damaged, steel will start to be corroded. The corrosion resistance of stainless steel depends on the chromium, chromium is a part of the composition of steel, chromium on the steel treatment, the appearance of the oxide type will be changed to similar to pure chromium metal on the surface oxide. This tightly adhered chromium-rich oxide maintains the appearance and avoids further oxidation.
The heat treatment process includes heating, heat preservation, cooling, etc., in order to reduce the metal deformation during the forming process of hardening and other deficiencies, so that the deformation of the pipe after processing to restore the performance, to improve its performance.
Now the most common heat treatment tools include electric furnace and reverberatory furnace; common control mode for the automatic temperature control.
Different
304 stainless steel tube fittings on the heat treatment requirements are different, and not all deformation of the tools to be heat treatment, usually low carbon steel pipe fittings the final temperature of not less than 723 ℃, then you can not heat treatment, if Below this temperature or temperature above 1000 ° C should be heat treated.
