What is stainless steel?

How is stainless steel manufactured? How durable is the material, can it loose its rust resistance?

Stainless steel is the term (designation, expression) for steel alloys with largely varying (diverging) properties (characteristics, features, pers: traits). It is a common property of all stainless steels (For all stainless steels it applies, is applicable, holds true) that they contain (consist of, include) at least 12% chromium.

By the chemical processes between the chromium included in the steel and the oxygen molecules in the air a thin chromium oxide layer develops at the surface. This layer (the latter) protects the steel from rust and other types of corrosion.

This layer functions like a protective coat(ing) (cover) or a different surface treatment such as electroplating. If, however, common steel gets into contact with oxygen and water, iron oxide develops (is formed, established) -- that means rust.

Stainless steel on the contrary doesn't need any surface treatment since it establishes its own protective coat. Although the chromium oxide layer gradually wears out in the course of time (gradually), it rebuilds under normal conditions due to the reaction of the chromium with the oxygen in the air.

Due (Thanks, Grace) to this characteristic (property, feature), stainless steel can be ground, abraded and scratched without rusting. Therefore (for this/that reason, that's why, thus, hence) it is well-suited (very suitable, it lends itself to, is suitable for, is appropriate for) for kitchen appliances and washing machines.

On the other hand (yet, however, though) stainless steel is not completely (entirely, perfectly) rust proof (rust resistant). When it gets in contact with sea water or acids, is dug in the earth or wrongly processed (machined, treated), it starts (commences, begins) -- just like conventional steel -- to rust and corrode. The cause (reason) for this is that under such conditions (circumstances) the chromium oxides cannot be formed (developed, built) and can't stick to (adhere to, attach to, settle on) the steel surface.

When manufacturing (production: commercial term) stainless steel, iron is alloyed with chromium, frequently also with nickel and manganese. An alloy is a mix (blend) of metals created (formed) by melting.

The most conventional type of stainless steel is the so-called 18-8-steel consisting of an iron alloy containing 18 percent chromium and eight percent nickel. It is used (utilized) for kitchen equipments (appliances), washing machines and screws.