Stainless steel classification:
1, according to the main chemical composition can be divided into chromium stainless steel, chromium nickel stainless steel, chromium manganese nitrogen stainless steel, chromium nickel molybdenum stainless steel and ultra-low carbon stainless steel, stainless steel, high pure molybdenum high such as stainless steel;
2, according to the performance characteristics of steel and USES classification, such as resistant to nitric acid (nitric acid level) stainless steel, stainless steel, sulfuric acid resistance, resistance to corrosion resistant materrial stainless steel stainless steel, high strength stress stainless steel, etc.
3, according to the functions and features of steel classification, such as low temperature stainless steel, no magnetic stainless steel, cutting stainless steel, stainless steel superplastic etc.
Four, the United States classification methods: 200, 300, 400 series product features and use. (201, 202, 300, 301, mostly used to decorate material similar material).
The 200 series: austenitic stainless steel. Features: contain Ni amount low is easy to rust. Derusting: use light cream, water light cream, bright and clean water, and rust: protect membrane liquid water, protect membrane fluid.
USES: as stainless steel strip steel, used to decorate material, stainless steel doors and Windows, stainless steel stair armrest, to guard against theft, etc.
The 300 series: austenitic stainless steel. Features: contain Ni volume is high, corrosion resistance. USES: used in industry, chemical equipment, dyeing and printing equipment, etc.
The 400 series: horse austenitic stainless steel, ferrite. Features: do not contain Ni, easy to rust. Rust, tableware, cutting tool, cutting tools for the more.
5, usually in metallographic composition classification
(A) austenitic stainless steel: austenitic stainless steel body with 200 and 300 series of digital sign. The microstructure for austenitic. It is in the high chromium stainless steel added to the appropriate nickel (nickel quality score is 8% ~ 25%) and form.
1 Cr18Ni9Ti (321), 0 Cr18Ni9 (302), 00 Cr17Ni14M02 (316 L)
Advantages: easy welding, plasticity is good (not easy to break), deformation, good stability (is not easy to rust), easy passivation. Faults: but to solution containing chlorine ion (CL-medium particularly sensitive, easy to happen stress corrosion.
Ferrite (F) stainless steel: the 400 series of digital said. Its internal microstructure for ferrite, its chromium quality score in the 11.5% to 32.0% range. With the improvement of chrome content, the acid and performance improved, join molybdenum (Mo), which can improve the acid corrosion and stress corrosion resistance ability. 00 Cr12, 1 Cr17 (430), 00 Cr17Mo, 00 Cr30Mo2, Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28, etc
Advantages: including chromium volume is high, thermal conductivity, better stability, heat dissipation good sex. Faults: but the mechanical properties and the process performance is poor.
Application: mainly used for stress not big acid structure and be antioxidant steel used, for example, kitchen is provided, the exhaust pipe (motorcycle back).
Martensite (M) stainless steel: the 400 series of digital said. Its microstructure for martensite. This kind of steel in the quality of chromium concentration was 11.5% ~ 18.0%, but the quality of carbon scores can be as high as 0.6%. The higher the carbon content, improving the strength and hardness of the steel. In this kind of steel with a small amount of nickel can to make martensite, at the same time and improve the corrosion resistance. 1 Cr13 (410), 2 Cr13 (420), 3 Cr13 (), 1 Cr17Ni2 ()
Advantage: high carbon content, high hardness. Weakness: this kind of steel plasticity and welding the gender is poorer. USES: mold, underground pipelines, cutting tool, cutting tools, tableware, bolts, nuts.
Duplex stainless steel
(dual) ferritic-martensite steel stainless steel:
(dual) martensite stainless steel-carbide steel:
(dual) austenitic/ferritic (A to F) stainless steel: the microstructure for austenite plus ferrite. Ferrite is less than 10% of the volume fraction of stainless steel, is in the austenitic steel on the basis of the development of the material.
(dual) austenitic-martensite (A-M) stainless steel:
Advantages: easy to forming and welding, high strength (C can reach 100 a 150) and hot strong sex good,
Faults: but because of containing cr low in heat treatment and have chrome carbide separation, so the corrosion resistance than standard austenitic stainless steel lower.
USES: now this kind of steel is mainly used in aviation industry and the rockets missile production, general machinery manufacturing application is not common, and in the classification and put them on high strength steel for
Precipitation sclerosis (PH) stainless steel: according to the organization forms can be divided into three groups: precipitation sclerosis half austenitic size, shape and precipitation sclerosis markov austenitic stainless steel precipitation sclerosis shape.
The steel of the organizational characteristics is in solid solution or annealing state has the austenite plus volume is divided into 5% ~ 20% of ferrite organization.
Advantages and application: this kind of steel has very good forming performance and good weldability, and can be used for high strength of the material in the nuclear industry, aviation and aerospace industry, been applied.