Stainless steel, which is an iron alloy, is a group of steel that contains 10.5% -1.2% chromium. The chromium element in stainless steel, which is distinguished from other steel groups with its stainless feature, provides protection from oxygen by covering the surface of the material with the oxide layer it forms on the surface. The oxide layer, which is also waterproof, is too thin to be seen with the eye.
Stainless steels are divided into five groups in terms of their structure and properties.
1-Ferritic stainless steels: The carbon ratio of the steels in this group is low and their corrosion resistance is medium. The strength of ferritic stainless steels that are not easily shaped cannot be increased by heat treatment and they show magnetic properties.
Ferritic stainless steels are generally used in decorative applications, hot water tanks, exhaust parts, automobile chassis parts and kitchen tools.
2-Martensitic stainless steels: The hardness of this group of steels with high strength is equally high and their brittleness is also high. In order to minimize the brittleness of these steels, the hardness can be reduced and brought to the desired strength level by annealing during the production phase. The corrosion resistance of martensitic stainless steels that can be heated is medium. This group of steels are generally used in cutting and piercing materials such as knives and surgical instruments.
3-Austenitic stainless steels: Since the stainless steels, which contain nickel element, turn into austenitic structure at room temperature, the shaping process of the steel gets easier. The mechanical strength of this group of steels, which have high strength and high corrosion resistance, can be increased by cold forming, at the same time partial magnetic properties can be gained. The use area of this steel group, which cannot be heat treated, is the machine manufacturing industry, food processing equipments and architectural applications.
4-Duplex stainless steels: This steel group, which contains both ferritic and austenitic structures together, provides both high strength and high hardness. Duplex stainless steels, which also provide toughness properties, have easy forming properties. These steels, which are salt resistant in nature, are used in sea and salt water environments, in the manufacture of heat exchangers and in the petrochemical industry.
5- Precipitation hardened stainless steel: This is the chromium-nickel alloy and heat-treated steel group containing elements such as aluminum, titanium and copper that provide precipitation hardening. Stainless steels, which have many properties and types such as strength, heat treatment and chip removal feature, are quite wide and their use can be encountered in every moment of life.