All metal and atmospheric oxygen in the reaction, formed in the surface oxide film. Unfortunately, in the ordinary carbon steel formed on the oxidation of iron oxide to continue, kept expanding rust, eventually forming holes. Can use paint or resistant to oxidation of the metal (for example, zinc, chromium and nickel) on plating to ensure that the surface of carbon steel, but, as we know, the protection is only a thin film. If the cover was damaged, the following steel began to rust.
The corrosion resistance of stainless steel depends on chrome, but because of the chromium is one part of the steel, so the protection method is not the same. In the chromium content up to 10. 5%, atmospheric corrosion resistance of steel increased significantly, but the chromium content is higher, although still can improve the corrosion resistance, but not obvious. Reason is that with chromium alloying of steel processing, change the type of surface oxide became similar to that of pure chromium oxide is formed on the metal surface. This tight adhesion of the surface of the rich chromium oxide protection, to prevent further oxidation. This kind of extremely thin oxide layer, you can see on side impact beams the surface of the steel through natural luster, make the surface of the stainless steel has a unique. And, if damaged surface, exposed by the steel surface and atmospheric response to repair itself, to form the "passive film," continued protection. Therefore, all stainless steel has a common characteristic, namely the chromium content in 10. More than 5%.
Stainless steel pipe connection is diversiform, common type of pipe fittings with compression type, pressure type, living type, push, push the thread, flange connection socket welding type, living type, welding and welding with traditional connection way of derived series connection. The connection mode, according to its principle, its applicable scope is also different, but most are cold drawn tubes convenient installation, firm and reliable. Joint seal or gasket material, most choose to meet the requirements of national standard of silicone rubber, NBR and epdm and so on, from the user's worries.
Conformity of broken tube connection steps: according to the required length cut pipe, tube broken, not too hard, to prevent the loss of circular pipes. Remove burrs: after pipe cutting, burr removal should be clean, in order to avoid cut seal ring. Scribing sign: in order to make steel tube inserted into the fitting socket completely, must be conducted in the length of the pipe to insert tag line drawing. Assembly: the sealing ring should be properly installed in the fitting u-shaped slot, a tube inserted into the fitting socket, wait for the pressure. A convex pressure welding, pressure welding, pipe fittings on mold the concave groove, jaw perpendicular to the pipe axis. Check: after the completion of beam impact tubes the pressure, the use of special gauge to check pressure size.