What are the materials made of stainless steel? What material is stainless steel made of

In layman's terms, stainless steel is steel that is not easy to rust, but in fact, some stainless steel has both stainless steel and acid resistance (corrosion resistance). The stainless steel and corrosion resistance of stainless steel are due to the formation of a chromium-rich oxide film (passivation film) on its surface. This rust and corrosion resistance are relative.

The test shows that the corrosion resistance of steel in the atmosphere, water and other weak media and oxidizing media such as nitric acid increases with the increase of chromium water content in steel, when the chromium content reaches a certain percentage, the corrosion resistance of steel undergoes a sudden change, that is, from easy rust to not easy to rust, from non-corrosion resistance to corrosion resistance. There are many ways to classify stainless steel. According to the microstructure classification at room temperature, there are martensitic type, austenitic type, ferrite and duplex stainless steel; According to the classification of the main chemical components, it can basically be divided into two systems: chromium stainless steel and chromium-nickel stainless steel; According to the use, there are nitric acid resistant stainless steel, sulfuric acid resistant stainless steel, seawater resistant stainless steel, etc., and according to the type of corrosion resistance, it can be divided into pitting corrosion resistant stainless steel, stress corrosion resistant stainless steel, intergranular corrosion resistant stainless steel, etc.; According to the functional characteristics, it can be divided into non-magnetic stainless steel, free-cutting stainless steel, low-temperature stainless steel, high-strength stainless steel and so on.

Due to its excellent corrosion resistance, formability, compatibility and strength and toughness in a wide temperature range, stainless steel has been widely used in heavy industry, light industry, daily necessities industry and building decoration industry.

Stainless steel is based on ordinary carbon steel, adding a group of steel with a mass fraction of chromium (WCR) greater than 12 alloying elements, which can maintain metallic luster under the action of air, that is, it has the characteristics of no rust. This is due to the fact that this type of steel contains a certain amount of chromium alloy elements, which can form a strong oxide film (passivation film) on the surface of the steel that does not dissolve in certain media, so that the metal is isolated from the external medium without chemical reaction. In this kind of steel, in addition to containing more chromium (Cr), some are also matched with the addition of more other alloying elements, such as nickel (Ni), so that it has good chemical stability in air, water, and vapor, and has enough stability in many kinds of acid, alkali, salt aqueous solution, even in high or low temperature environment, it can still maintain its corrosion resistance.

Stainless steel is made of ordinary steel, nickel and other materials. The raw material of stainless steel is ordinary carbon steel, and on this basis, other chemical elements are added, such as chromium, the content of which is more than 12%, and the material of stainless steel is formed by production. Its main feature is that it is not easy to rust, it is not easy to corrode under the action of the atmosphere, and it maintains the luster of the metal.

Features:

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 is also a special stainless steel for pressure vessels "GB24511 2009 Stainless steel plate and steel strip for pressure equipment".

Stainless steel is mainly composed of iron, chromium and nickel, in addition, there are: carbon, manganese, silicon, molybdenum, titanium, niobium, titanium, manganese, nitrogen, copper, cobalt, etc. Different varieties of stainless steel have different chemical elements.

The raw material of stainless steel is ordinary carbon steel, on the basis of which other chemical elements are added, such as chromium, stainless steel also contains Ni, Ti, Mn, N, Nb, Mo, Si, Cu and other elements.

Stainless steel is defined in GB T20878-2007 as stainless steel, corrosion resistance as the main characteristics, and the chromium content is at least, and the carbon content is not more than the maximum. 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 steel.

If you want stainless steel not to rust, you should pay attention to the environment not too humid, clean it regularly, and avoid contact with acidic and alkaline items for some stainless steel materials. For food-grade tableware, it is best to choose a model of 304 or 316, so as to ensure that it does not rust and will not cause damage to our human body.

Structural components

The corrosion resistance of stainless steel decreases with the increase of carbon content, therefore, the carbon content of most stainless steels is low, and the maximum is not exceeded, and some steels even have a C (carbon content) lower than e.g. 00Cr12).

The main alloying element in stainless steel is CR (chromium), and only when the CR content reaches a certain value, the steel is corrosion-resistant. Therefore, stainless steel generally has a cr (chromium) content of at least. Stainless steel also contains elements such as Ni, Ti, Mn, N, Nb, Mo, Si, and Cu.

The above content refers to Encyclopedia - Stainless Steel (Metal Material).

Stainless steel is a corrosion-resistant and high-temperature resistant alloy, which belongs to alloy metal materials. It has a brightness close to the mirror surface, hard and cold to the touch, and is a relatively avant-garde decorative material, with excellent corrosion resistance, formability, compatibility and toughness and other series characteristics, which are used in heavy industry, light industry, daily necessities industry and building decoration and other industries.

Summary of stainless steelStainless steel is the abbreviation of stainless acid-resistant steel, and the steel grades that are resistant to weak corrosive media such as air, steam, and water or have stainless steel are called stainless steel, and the steel grades that are chemically resistant to acid-corrosion such as acid, alkali, and salt are called acid-resistant steel. The corrosion resistance of stainless steel decreases with the increase of carbon content, therefore, most stainless steels have a low carbon content and the maximum does not exceed.

The requirements for welding performance vary depending on the use of the product. A type of tableware generally does not require welding performance, even including some pot enterprises. However, the vast majority of products need raw materials with good welding performance, such as second-class tableware, thermos cups, steel pipes, water heaters, water dispensers, etc.

The raw material of stainless steel is ordinary carbon steel.

The raw material of stainless steel is ordinary carbon steel, and other chemical elements, such as chromium, are added, and the content is more than 12, which is the stainless steel material for production molding. The main characteristics of stainless steel are that it is not easy to rust, it is not easy to corrode under the action of the atmosphere, and it maintains the brightness of the metal. Of course, stainless steel is not easy to rust, and it is also divided into other types.

Due to different chemical elements, the classification will be different, the common ones are stainless steel, corrosion-resistant stainless steel, stainless steel is not necessarily corrosion-resistant, and corrosion-resistant steel will definitely not rust. Comparatively speaking, stainless steel has strong stability, strength and plasticity. The stainless steel of ordinary carbon steel, when the steel contains about 18, Ni8 10, and C, it has a stable austenite structure.

Stainless steel plate purchase skills:

1. Distinguish the material.

The commonly used materials of colored stainless steel plates on the market are divided into equal models, which are made by processing and coloring. Among these models, the 316 has the best corrosion resistance, and the worst is the 201, and the difference is also relatively large. Therefore, some black merchants often use 201 with bad material instead of 304 and 316, and some will use water plating coloring process to replace the vacuum ion plating coloring process, so that many building decoration projects install stainless steel plates, and the surface has the problem of color falling off, rust and even breakage.

2. Surface coloring process.

The stainless steel surface coloring process will affect the height of the industry, mainly the water plating coloring process and the vacuum coloring process, the former gives people an unreal and unrefined feeling, just like spraying on it, and it will also produce wastewater pollution, which is low. The latter is relatively environmentally friendly and does not produce toxic or polluting substances.

3. Observe the metal surface.

Since the colored stainless steel plate is mainly used for architectural decoration, the ornamentality is very important. When inspecting the goods, the owners need to check the surface carefully, and see if there is any color difference, as well as scratches, sand holes, peeling water marks and other problems.

Summary. In addition, ferritic stainless steel. The chromium content is improved, and the resistance to chloride stress corrosion is better than that of other types of stainless steel.

Austenitic stainless steel. The chromium content is greater than 18%, and it also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. It has good comprehensive performance and can resist corrosion of a variety of media.

Austenitic-ferritic duplex stainless steels. It combines the advantages of austenitic and ferritic stainless steels with superplasticity.

Martensitic stainless steel. High strength, but poor plasticity and weldability.

Stainless steel is available in several materials.

Typing pro.

Hello answer, the stainless steel on the market is martensitic stainless steel, ferritic stainless steel, duplex stainless steel, austenitic stainless steel, and precipitation hardening stainless steel.

And our daily 304 316 is Austrian-style stainless steel pro.

It is not magnetic.

Suitable for food industry, industrial equipment, etc.

In addition, ferritic stainless steel. The chromium content is improved, and the resistance to chloride stress corrosion is better than that of other types of stainless steels, austenitic stainless steels. The chromium content is greater than 18%, and it also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements.

It has good comprehensive performance and can resist corrosion of a variety of media. Austenitic-ferritic duplex stainless steels. It combines the advantages of austenitic and ferritic stainless steels with superplasticity.

Martensitic stainless steel. High strength, but poor plasticity and weldability.

I hope mine can help you.

Stainless steel material, I believe everyone is familiar with, it is often used in our lives and buildings, it has a good corrosion resistance effect, and the service life is also very long. There are many types of stainless steel materials on the market, what are the materials? How to buy?

Let's take a look at the relevant knowledge right away.

1. What are the types of stainless steel materials?

There are five types of stainless steel materials on the market, namely martensitic stainless steel, ferritic stainless steel, duplex stainless steel, austenitic stainless steel, and precipitation hardening stainless steel. Among them, etc. are austenitic stainless steels, which are not magnetic; And so on martensitic stainless steel, some people call them stainless iron, with high magnetic properties. In life, we mainly use 304 stainless steel, which is suitable for food industry, industrial equipment and so on.

Second, how to identify stainless steel materials.

1. Identification with magnets.

Chromium stainless steel is magnetic, and can be attracted to magnets in any state; Chromium-nickel stainless steel is non-magnetic when annealed, and may be magnetic after cold working; And high manganese steel, with high manganese content, is absolutely non-magnetic.

2. Identification of color.

The color of the pickled stainless steel surface is different, for example, the color of chromium-nickel stainless steel is silver-white jade, the color of chromium stainless steel is gray-white, and chromium-manganese-nitrogen stainless steel is similar to chromium-nickel. Unpickled stainless steel surface color: chrome-nickel steel is brownish-white, chrome steel is brownish-black, chromium-manganese nitrogen is black.

3. Identification with copper sulfate.

First remove the oxide layer on the stainless steel, and then put a drop of water, if wiped with copper sulfate, the stainless steel will not change after wiping; If it is purple-red, it proves that it is high manganese steel, and if it is magnetic, it is ordinary steel or low alloy steel.

Conclusion of the article: What are the types of stainless steel materials and identification methods are introduced here, I hope it will be helpful to you. If you want to know more about related knowledge, please continue to pay attention to the Qeeka Home information platform, and more exciting content will be presented to you in the future.

Stainless steel materials include martensitic stainless steel, precipitation hardening stainless steel, ferritic stainless steel, duplex stainless steel, and austenitic stainless steel. Among them, duplex stainless steel, which has the characteristics of both austenitic and ferritic stainless steel. Stainless steel can be divided into four categories, namely stainless steel, acid-resistant stainless steel, heat-resistant stainless steel, and low-temperature stainless steel.

Basal tissue classification.

1. Ferritic stainless steel. Chromium content 12% 30%. Its corrosion resistance, toughness and weldability improve with the increase of chromium content, and its chloride stress corrosion resistance is better than that of other types of stainless steel.

2. Austenitic stainless steel. The chromium content is greater than 18%, and it also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. It has good comprehensive performance and can resist corrosion of a variety of media.

3. Austenitic-ferritic duplex stainless steel. It combines the advantages of austenitic and ferritic stainless steels with superplasticity.

4. Maraging stainless steel. High strength, but poor plasticity and weldability.

Stainless steel equipment can be used to cause damage, defects and other substances that affect the surface, such as dust, floating iron powder or embedded iron, hot tempering color and other oxide layers, rust spots, grinding burrs, welding arc marks, welding spatter, fluxes, welding defects, oils and greases, residual adhesives and paints, chalk and marker marks, etc. The vast majority are ignored or poorly done because they ignore their harmful effects.

However, they are potentially harmful to oxidizing protective films. Once the protective film is damaged, thinned or otherwise altered, the stainless steel underneath will begin to corrode.