How many types of stainless steel are there What are the types of stainless steel?

There are so many variety, and it's very complicated. It is recommended that you go to the encyclopedia to see.

The commonly used ones are 201 and 304.

There are many types of stainless steel, which can be divided into several categories according to the organizational structure at room temperature:

1 Austenite type: such as etc.;

2 Martensite or ferrite type: such as etc.;

The austenite type is amagnetic or weakly magnetic, and the martensitic or ferrite is magnetic.

As mentioned above, austenite is non-magnetic or weakly magnetic, while martensitic or ferrite is magnetic, due to improper segregation or heat treatment during smelting, it will cause a small amount of martensitic or ferrite structure in austenite 304 stainless steel. In this way, there will be a weak magnetic property in 304 stainless steel.

In addition, after cold working, the microstructure of 304 stainless steel will also be transformed to martensitic, and the greater the deformation degree of cold working, the more martensitic transformation, and the greater the magnetic property of the steel. Like a batch of steel strips, 76 tubes are produced, and there is no obvious magnetic inductance, and tubes are produced. Due to the large deformation of the bend, the magnetic induction is more obvious, and the deformation of the square rectangular pipe is larger than that of the round pipe, especially the corner part, the deformation is more intense, and the magnetic induction is more obvious.

In order to completely eliminate the magnetic properties of 304 steel caused by the above reasons, the magnetism can be eliminated by high-temperature solution treatment and the restoration of stable austenite structure.

In particular, it should be mentioned that the magnetism of 304 stainless steel caused by the above reasons is not at the same level as that of stainless steel made of other materials, such as 430 and carbon steel, that is to say, the magnetism of 304 steel always shows weak magnetism.

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.

Heat Resistance In intermittent use below 1600 degrees 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.

Heat treatment annealing is carried out 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.

There are three main types of stainless steels, namely austenitic stainless steel, ferritic stainless steel, and martensitic stainless steel.

1. Austenitic stainless steel.

The matrix is dominated by an austenite structure (cy-phase) with a face-centered cubic crystal structure, which is non-magnetic, and is mainly strengthened by cold working (and may lead to a certain magnetism) of stainless steel. The American Iron and Steel Institute is numbered with the 200 and 300 series, such as the 304.

2. Ferritic stainless steel.

The matrix is dominated by a ferrite structure (phase A) with a body-centered cubic crystal structure, which is magnetic, and generally cannot be hardened by heat treatment, but can be slightly strengthened by cold working. The American Iron and Steel Institute designates 430 and 446.

3. Martensite stainless steel.

The matrix is a martensitic structure (body-centered cubic or cubic), magnetic, and its mechanical properties can be adjusted by heat treatment. The American Iron and Steel Institute is marked by numbers 410, 420 and 440. Martensite has an austenitic structure at high temperatures, and when cooled to room temperature at the appropriate rate, the austenite structure is able to transform into martensite (i.e., hardened).

The main factors affecting stainless steel corrosion.

1. The content of alloying elements.

Generally speaking, the chromium content in steel is not easy to rust. The higher the content of chromium and nickel, the better the corrosion resistance, such as the nickel content of 304 material is 8-10%, and the chromium content is 18-20%, so stainless steel will not rust under normal circumstances.

2. The smelting process of the production enterprise will also affect the corrosion resistance of stainless steel.

The large stainless steel plant with good smelting technology, advanced equipment and advanced technology can be guaranteed in the control of alloying elements, the removal of impurities, and the control of billet cooling temperature, so the product quality is stable and reliable, and it is not easy to rust. On the contrary, some small steel mills have backward equipment and backward technology, and in the smelting process, impurities cannot be removed, and the products produced will inevitably rust.

3. The external environment, the climate is dry and the ventilated environment is not easy to rust.

The air humidity is high, and the continuous rainy weather, or the environmental area with high pH in the air is prone to rust. 304 stainless steel, if the surrounding environment is too poor, it will also rust. <>

The types of stainless steel plates are as follows:

Clause. 1. According to the classification of use, there are armor, automobiles, roofing, electricians, spring steel plates, etc.

Clause. 2. According to the classification of steel grades, there are martensitic type, ferritic type, austenitic steel plate, etc.;

Clause. 3. According to the thickness classification, there are four types: extra-thick plate, thick plate, medium plate and thin plate.

Summary. Hello, dear.

Hello, dear.

Generally, according to the metallographic structure, ordinary stainless steels are divided into three categories: austenitic stainless steel, ferritic stainless steel, and martensitic stainless steel. On the basis of these three basic metallographic structures, duplex steels, precipitation-hardened stainless steels and high-alloy steels with an iron content of less than 50% are derived for specific needs and purposes.