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Classification of stainless steel commonly used in the civil market industrial field

Classification of stainless steel commonly used in the civil market industrial field

Time:2022-03-17 Source:China Wuxi JiaNuo Special Steel Co.

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Stainless steel is short for stainless steel, acid-resistant steel. In the field of metallurgy and materials science, according to the main performance characteristics of steel, a series of iron-based alloys with a chromium content of 12% or more, the main performance is corrosion resistance and corrosion resistance, called stainless steel. Generally known as stainless steel, in the atmosphere, water vapor and fresh water and other weak corrosive media do not rust not resistant to corrosion, in acid, alkali and other strong corrosive environment is called stainless steel. And corrosive environments. Acid-resistant steel. The two steels differ in corrosion resistance due to different compositions, the former has a low degree of alloying, generally not acid-resistant, the latter has a high degree of alloying, both acid-resistant and corrosion-resistant.

There are many types of stainless steel with different properties, and the general classification method is as follows.

Classification by steel structure

Classified by steel structure, such as ferritic stainless steel, martensitic stainless steel, austenitic stainless steel, duplex stainless steel, precipitation hardening stainless steel and other five categories.

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They are classified according to the main chemical composition of the steel or certain characteristic elements of the steel.

Chromium stainless steel, chromium-nickel stainless steel, chromium-nickel-molybdenum stainless steel, ultra-low carbon stainless steel, high molybdenum stainless steel, high purity stainless steel, etc.

Classification by American standard

The first digit of the grade indicates the series, the last two digits indicate the steel grade, and the additional letters indicate the grade modification. The 200 series is an austenitic stainless steel, but some of the nickel is replaced by manganese and nitrogen. The 300 series is a nickel-stabilized austenitic steel. The 400 series is a chromium stainless steel that contains no nickel or no more than 2.5% nickel.

Classified by performance characteristics and steel applications

Acid-resistant (nitric acid grade) stainless steel, sulfuric acid-resistant stainless steel, pitting-resistant stainless steel, stress corrosion-resistant stainless steel, high-strength stainless steel, etc.

Classified by the functional characteristics of steel

Low temperature stainless steel, non-magnetic stainless steel, free-cutting stainless steel, superplastic stainless steel, etc.

Today’s common classification method is based on the structural properties of steel and the chemical composition of steel properties, and a combination of both. For example, according to the organizational properties of steel is divided into ferritic steel, martensitic steel, austenitic steel, duplex steel, precipitation hardening steel five categories, according to the chemical composition of steel is divided into two categories. Grades of chromium stainless steel and chromium-nickel stainless steel; the combination of the two methods is divided into ferritic chromium stainless steel, martensitic chromium stainless steel, austenitic chromium-nickel stainless steel (including austenitic chromium-manganese (nitrogen) stainless steel) and austenitic. – There are five types of ferritic duplex stainless steels and precipitation hardening chromium-nickel stainless steels.

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