The Principle of Stainless Steel not Rusting

Stainless steel elbow stock raw materials mainly include steel ingots, billets, steel and other raw materials, different raw materials in is use occupies an important position. Steel is the ingot, billet or steel through pressure processing into the required variety of shapes, sizes and properties of the material. Due to the high viscosity of Stainless steel elbow material, poor chip breaking performance, so in the stainless steel elbow tapping process using a tap is prone to chip scraping workpiece threads or tap chipping and other phenomena, affecting processing efficiency and thread quality. All metals react with oxygen in the atmosphere to form an oxide film on the surface. Unfortunately, the iron oxide formed on plain carbon steel continues to oxidize, causing the rust to expand and Z eventually form holes. The surface of stainless steel elbows can be secured by plating using paint or oxidation-resistant metals (for example, zinc, nickel and chromium), but, as is well known, this protection is only a thin film. If the protective layer is broken, the steel below will begin to rust.

If we are talking about processing stainless steel pipe fittings then it is different, because it is a metallurgical process, from the inside out. The secret of stainless steel pipe fittings is the addition of chromium metal in the carbon steel, and the content is not low, at about 12%, after he comes into contact with the air chromium will react with oxygen to form a dense passivation film on the surface of the carbon steel, which can effectively and continuously protect the stainless steel pipe fittings. And this layer of passivation film is super thin, can see the natural luster of the steel surface, making stainless steel pipe fittings have a very unique surface characteristics. But there is no guarantee that this protective film will not be destroyed, once the damage to the exposed steel will react with oxygen, will re-form a passivation film, continue to serve his job. Theoretically, stainless steel pipe fittings will not rust, but in practice, the surface of many different degrees of wet and dry environment rust is also normal.