Stainless Steel

An alloy of iron and chromium, which may contain nickel, molybdenum, among other elements. This alloy has physicochemical properties superior to common steels. Its main feature is high resistance to atmospheric oxidation. Their families classified according to their microstructure are: austenitic, martensitic, hardened by precipitation and duplex.

Forms

FOR SURVEILLANCE INSTRUMENTAL
Redwave Bars
Plates

FOR SURVEILLANCE CANULATED
Cannulated Bars

Alloy elements, specifically chromium, have excellent corrosion resistance compared to carbon steels. They're actually oxidizing steels. That is, the chromium present in the alloy oxidizes in contact with air oxygen, forming a very thin and stable film of chromium oxide - Cr2O3 - which forms on the surface exposed to the medium. It is called a passive layer and has the function of protecting the steel surface from corrosive processes. For this, a minimum amount of chromium of about 11% by mass is required. This film is adherent and waterproof, isolating the metal below it from the aggressive medium. Therefore, care should be taken not to reduce the chromium content of stainless steels locally during processing. This process is known in metallurgical as passive. Because it is very thin (about 100 angstrons), the film has little interaction with light and allows the material to continue presenting its characteristic brightness.

History

Stainless steel was discovered by Harry Brearley (1871-1948), who began working as a worker in a steel producer at the age of 12 in his homeland, Sheffield, England.

In 1912, Harry began to investigate, at the request of the weapons manufacturers, a metal alloy that presented a greater resistance to wear that occurred inside the firearm pipes as a result of the heat released.
For the gas.

At first, his research consisted of investigating a league that presented greater erosion resistance. However, when performing the chemical attack to reveal the microstructure of these new steels with high levels of chromium that he was researching, Brearley noted that nitric acid (a common reactive for steels) had no effect.

Brearley did not obtain a metal alloy that resisted wear, but obtained a corrosion-resistant metal alloy. The immediate application was intended for the manufacture of cutlery, which until then were manufactured from carbon steel and easily corroded due to the acids present in food.

Types of stainless steel

Austenitics (corrosion resistant):