The classification of stainless steel grades, what are the commonly used stainless steel grades

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Generally 201 202 304 316 These 202 and 304 are used more.

316 and 317 stainless steels (see below for the properties of 317 stainless steel) are molybdenum-containing stainless steel grades. The molybdenum content in 317 stainless steel is slightly higher than that in 316 stainless steel. Due to the molybdenum in the steel, the overall properties of this steel grade are better than those of 310 and 304 stainless steels, and under high temperature conditions, when the concentration of sulfuric acid is below 15 and above 85, 316 stainless steel has a wide range of uses.

316 stainless steel also has good chloride attack properties, so it is commonly used in marine environments.

The maximum carbon content of 316L stainless steel can be used in applications that cannot be annealed after welding and where maximum corrosion resistance is required.

Corrosion resistance. The corrosion resistance is better than that of 304 stainless steel, and it has good corrosion resistance in the production process of pulp and paper. And 316 stainless steel is also resistant to the erosion of the ocean and the aggressive industrial atmosphere.

In intermittent use with heat resistance below 1600 degrees Celsius and continuous use below 1700 degrees, 316 stainless steel has good oxidation resistance. In the range of 800-1575 degrees, it is best not to act 316 stainless steel continuously, but when 316 stainless steel is used continuously outside of this temperature range, the stainless steel has good heat resistance. 316L stainless steel has better resistance to carbide precipitation than 316 stainless steel, and can be used in the above temperature ranges.

The heat treatment is annealed in the temperature range of 1850-2050 degrees, followed by rapid annealing, followed by rapid cooling. 316 stainless steel cannot be overheated for hardening.

Welding: 316 stainless steel has good welding properties. All standard welding methods can be used for welding. When welding, according to the application, 316CB, 316L or 309CB stainless steel packing rod or welding rod can be used for welding.

For optimal corrosion resistance, the welded sections of 316 stainless steel need to be annealed after welding. If 316L stainless steel is used, post-weld annealing is not required.

Austenitic stainless steel) mainly includes:

321, (1cr18ni9ti) also known as 18-8

304 ，(0cr18ni9 )

304l , 00cr19ni10 )

306 , 0cr17ni12mo2 )

316l , 00cr17ni14mo2 )

mo2ti。

Main difference: 321 contains titanium.

316 containing molybdenum.

304 contains neither titanium nor molybdenum.

Mo2Ti contains both molybdenum and titanium.

The performance of 316L is the best, and the performance of 321 304 is average.

201: Manganese instead of nickel stainless steel, with a certain acid and alkali resistance, high density, polishing without bubbles, used in the case, decorative tubes, industrial pipes and other shallow stretch products.

202: It belongs to low-nickel and high-manganese stainless steel, with nickel and manganese content of about 8%, under weak corrosion conditions, it can replace 304, and is cost-effective, mainly used in building decoration, highway guardrails, municipal engineering, glass handrails, highway facilities, etc.

304: general-purpose stainless steel, with good corrosion resistance, heat resistance, low temperature strength and mechanical properties, high toughness, used in food industry, medical industry, industry, chemical industry, home decoration industry.

304L: Low carbon 304 stainless steel, used in corrosion resistance and formability of equipment parts.

316: MO is added, which has excellent high temperature corrosion resistance, and is used in seawater equipment, chemical industry, food industry, and paper industry.

321: Excellent high-temperature stress breaking performance and high-temperature creep resistance.

430: Heat fatigue resistance, the coefficient of thermal expansion is smaller than that of austenite, and it is used in household appliances and architectural decoration.

410: high hardness, toughness, good corrosion resistance, large thermal conductivity, small expansion coefficient, good oxidation resistance, used in the manufacture of atmosphere, water vapor, water and oxidizing acid corrosive parts.

Stainless steel is usually divided into a variety of models such as S, 310S, etc. Among them, S and 310S belong to austenitic stainless steel, which does not contain magnetism and can resist corrosion of a variety of media, and belongs to martensitic stainless steel, which has magnetism and high strength, but poor plasticity and weldability.

1. What is stainless steel.

Stainless steel is the abbreviation of stainless acid resistant steel, and the steel grade that is resistant to weak corrosive media such as air, steam, and water or has stainless steel is called stainless steelThe steel that is resistant to chemical corrosion media (acid, alkali, salt and other chemical corrosion) is called acid-resistant steel.

Stainless steel is often divided into martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the microstructure. In addition, it can be divided into chromium stainless steel, chromium-nickel stainless steel and chromium-manganese-nitrogen stainless steel according to the composition.

There are many models of stainless steel, and the common ones are mainly as follows:

Type: A basic grade with lower corrosion resistance than Type 304. This type is resistant to corrosion, such as nitric acid, sulfur gas, and many organic and food acids.

Type: This type has a lower chromium content and adds aluminum. After cooling from high temperatures, this chemical helps prevent hardening. Typical applications include heat exchangers.

Type: One of the cheapest grades of stainless steel due to the reduced chromium content. This type can only be used for interior or exterior parts in non-critical corrosive environments. Typical applications include silencers.

Type: This molybdenum content increases, which improves corrosion resistance. Typical applications can include automotive trim parts and fasteners.

Type: FOR has been added to this grade to improve its corrosion and heat resistance. The most typical applications include deep-drawn parts.

Type: Improved scaling resistance due to increased chromium content. Applications can include furnace and heater components.

Type: Even higher chromium content is added to further improve corrosion and scale resistance at high temperatures. This grade has excellent oxidation resistance in sulfuric acid environments.

Type: One of the most commonly used (austenitic) stainless steel grades. Its high content of chromium and nickel makes it the first choice for the manufacture of processing equipment for the chemical (light chemicals), food, dairy, and beverage industries. This grade has an excellent combination of strength, corrosion resistance and fabric properties.

Type: This stainless steel grade contains 18 chromium, 14 nickel and added molybdenum. These combine to improve its corrosion resistance.

In particular, molybdenum is used to help control pitted corrosion of corrosion. This grade resists fouling at temperatures up to 1600 F. Type 316 is used in chemical processing, pulp and paper industry, food and beverage processing and distribution, and in highly corrosive environments.

It is also used in the marine industry due to its corrosion resistance.

Type: Molybdenum content higher than 316, used in highly corrosive environments. The molybdenum content of this grade must be greater than 3. Scrubber systems commonly used in air pollution control devices to remove particulate matter and/or gases from industrial exhaust gas streams.

Type: Titanium content is at least five times the carbon content. This is done to reduce or eliminate chromium carbide precipitation due to welding or exposure to high temperatures. Used in the aerospace industry.

Stainless steel model division basis

1. According to the material, it is divided into: 200 series (201 and series l l and 310s).

2. According to the length of the steel pipe, it is divided into: standard size (6m) and customized size (according to customer requirements).

3. Divide according to the shape of the stainless steel pipe.

Stainless steels can generally be divided into: ferritic stainless steels, austenitic stainless steels, martensitic stainless steels, and some duplex stainless steels.

Stainless steel is usually divided into a variety of models such as S, 310S, etc.

The types of stainless steel include martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel, precipitation hardening stainless steel, stainless steel plate and steel strip for pressure equipment, etc.

Martensitic steel: due to its high carbon content, it has high strength, hardness and wear resistance, but the corrosion resistance is slightly worse. Ferritic steel: Because of its high chromium content, it has good corrosion resistance and oxidation resistance, but poor mechanical and technological properties.

Austenitic steel: This type of steel has good plasticity, toughness, weldability, corrosion resistance, non-magnetic or weak magnetic properties.

The types of stainless steel are divided into martensitic steel, ferritic steel, austenitic steel, precipitation hardening stainless steel, etc., according to the composition of chromium stainless steel, chromium-nickel stainless steel, and chromium-manganese-nitrogen stainless steel. The model number in China is represented by element symbols and numbers, such as 3cr13. In the U.S., it's represented by numeric symbols, such as .

According to the American notation method, stainless steel models are commonly represented by digital symbols, including 200 series, 300 series, and 400 series.

The more commonly used classification of stainless steel is divided into martensitic steel, ferritic steel, austenitic steel, austenitic-ferritic (duplex) stainless steel and precipitation hardening stainless steel according to the microstructure.

Stainless steel has weldability, corrosion resistance, heat resistance, corrosion resistance, etc.

There are 5 types of stainless steels commonly found in the market, namely martensitic, ferritic, duplex, austenitic and precipitation hardening steel.

1. Martensitic stainless steel.

Stainless steel, whose mechanical properties can be adjusted through heat treatment, is a hardenable stainless steel of the same type. Typical grades are CR13 type, such as 20Cr1, 30Cr13, 40Cr13, etc.

2. Ferrite.

Stainless steel, whose mechanical properties can be adjusted through heat treatment, is a class of stainless steel that can be hardened in layman's terms. Typical grade is CR13.

3. Duplex stainless steel.

Duplex stainless steel (or 4462 stainless steel) is an extremely corrosion-resistant grade of stainless steel.

4. Austenite.

Stainless steel with austenitic structure at room temperature. When the steel contains about 18% Cr, 8% Ni and 10%, and C, it has a stable austenite structure.

5. Precipitation hardening stainless steel.

It is a stainless steel with austenitic and ferrite finger hail structures, which each accounts for about half of the structure. In the case of low C content, the CR content is 18% to 28%, and the Ni content is 3% to 10%.

The above content refers to Encyclopedia - stainless steel material.