This is because austenitic stainless steel contains chromium, which reacts with oxygen to form a passivation film, and nickel, which improves the oxide film's adhesion formed by chromium. The oxide film made of chromium forms a new film immediately, even if it is scratched and disappears. The oxide film can be removed by special processing, but in that case, the corrosion resistance will be reduced.

Even so, stainless steel also rusts?

There is an environment where even stainless steel, which is hard to rust, will rust. Then, in what cases stainless steel rusts, the environment where stainless steel rusts are summarized below.

1. Get rust

If you touch a metal that has already rusted for a long time, it will react with oxygen in the air, and only that part will rust. In addition, stainless steel is not rusted, but rust adheres to the oxide film of stainless steel, resulting in a "rusted" state.

2. Rust due to scratches

It may be scratched and then rusted before the oxide film regenerates. Under the oxide film, it is easy to rust like iron. Therefore, only the scratched part will rust.

3. Rust that occurs in response to chlorine-based substances

Even stainless steel is vulnerable to chlorine, and the oxide film may be destroyed by seawater or chlorine bleach that is often used during cleaning. Red rust easily adheres before the oxide film is regenerated, and even stainless steel with excellent corrosion resistance will rust.

Special surface-finished stainless steel material reduces processing costs!

A major feature of stainless steel is that it does not rust easily, and it is used in various products. It is often used as a material for exposed parts of products such as covers and frames. Since it is the exposed part of the product, the appearance may be required, and properties such as resistance to rust. Examples of processing used there are surface finishes such as hairline finish and mirror surface/buffing. Stainless steel seamless tube suppliers are the best suppliers of stainless steel.

Hairline finish is a surface finish that polishes a metal surface with linear scratches as thin as hair. The hairline finish slightly reduces the stainless steel surface's metallic luster, giving it a multi-layered appearance.

On the other hand, buffing is a surface finish that enhances gloss by polishing the metal surface. The degree of gloss of buff polishing varies depending on the buff used. Still, in general, when it exceeds 700, it becomes almost the same gloss and reflection as a mirror, and this level of polishing is called mirror finish. Stainless steel pipe fittings manufacturers in India solves your problem related to stainless steel.

In the case of  Duplex 2205 Flanges, plate materials that are originally surface-finished, such as hairline finish and mirror surface/buffing, are distributed as special materials.

2507 Sheet SUS304-# 400

SUS304-Striped steel plate

It is a typical example, and it is possible to reduce the processing cost by using a plate material that has been originally surface-finished.