What s in stainless steel? I m new to stainless steel, and I don t understand a lot, so I find a hig

Dai Nan Zhong Yong Xin is a brand I have seen on Ali, Dai Nan Zhong Yong Xin stainless steel products Ali blog is well written, the story of cooperation between them and customers is written, and there is also professional knowledge of stainless steel.

I have read Dai Nan Zhong Yong Xin stainless steel products Ali blog after feeling that he treats any customer is the same, Zhong Yong Xin uses his popularity on the network and high customer satisfaction, the use of network orders, cluster enterprise production, and then they are responsible for quality management and supervision of the method, has benefited many cooperative customers.

Boss Tang of Yingshang County, Anhui Province is in his thirties, and his production of stainless steel bushings, stainless steel connectors, stainless steel spline shafts, etc., is mainly matched with some fire trucks, lifting lights, remote control lights and other manufacturers.

Boss Tang found "Zhongyongxin" on Alibaba with the keyword "stainless steel bar". Boss Tang first read the blog of Zhongyongxin manufacturer, and then found them for consultation, through conversation, they recognized their company's business philosophy, and also appreciated the personality of their general manager, and thought that the "Zhongyongxin" brand was trustworthy.

During the conversation, Boss Tang also told Zhong Yongxin that he was deceived by a company four years ago and lost nearly 70,000 yuan, so he is very cautious when cooperating with others now. Boss Tang said: "Seeing that your company participated in HC's 2010 Top 10 Outstanding Online Business Selection and successfully advanced for the second time, it seems that your online business is doing well, so I will identify you."

Later, Boss Tang bought a total of one ton of 304 light circles of Zhongyongxin 16 and 304 light circles of 13, signed the contract on the spot, and paid all the money in advance. Boss Tang also said that if he had the opportunity, he would introduce his fellow countrymen to Zhong Yongxin, and his fellow villagers were ready to do stainless steel material business.

It's too broad to explain.

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.

When manufacturing stainless steel, manufacturers must determine exactly what type of stainless steel they want to make. This is important because the grade of stainless steel they want to make affects the proportion of stainless steel materials present in the mixture, such as iron, carbon, nickel, etc. These ratios are not always accurate, and sometimes they are in a range because there is an inevitable risk of variation in the purity of each element in the mixture.

The principle of stainless steel

Stainless steel is essentially the product of a combination of steel and chromium, chromium can become good friends with oxygen, forming chromium oxide, this substance has a smooth and hard surface, and has a strong adhesion to iron, in addition, this chromium oxide can also be automatically repaired after destruction, so stainless steel will always look shiny.

From iron to steel to stainless steel, this technological breakthrough has accelerated the pace of human civilization, and today stainless steel masterpieces, razors, protective nets, sinks, etc. can be seen everywhere around people.

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 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.

Stainless steel is a corrosion-resistant, high-temperature resistant alloy and belongs to alloy metal materials. When the brightness is close to the mirror, it is intense and cold to the touch. It is a relatively avant-garde decorative material with excellent corrosion resistance, formability, compatibility and toughness.

It is used in heavy industry, light industry, daily necessities industry, building decoration and other industries.

It does not rust easily because stainless steel contains chromium, nickel, aluminum, and silicon in addition to iron. When chromium and other elements are added to the steel, the structure of the steel can be more homogeneous, which changes the properties of the steel and makes it difficult for it to penetrate corrosive substances. In addition, an oxide protective film adheres to the surface of the stainless steel, which naturally makes it difficult to rust.

Extended Materials: Key Features.

Weldability Different product uses have different requirements for welding performance. A type of tableware generally does not require welding performance, and even includes some pot enterprises. However, most products require raw materials with good welding properties.

Corrosion resistance. Most stainless steel products require good corrosion resistance, and some foreign businessmen also conduct corrosion resistance tests on the products: heat the aqueous solution of sodium chloride to boiling, pour out the solution after a period of time, wash and dry, and weigh the weight loss to determine the degree of corrosion (Note: When polishing the product, due to the iron composition in the abrasive cloth or sandpaper, rust spots will appear on the surface during the test) When the atomic percentage of the chromium content in the steel is not less than, the electrode potential of the steel will suddenly change from negative potential to positive potential, thus preventing electrochemical corrosion.

Polishing properties. In today's society, stainless steel products are generally polished during the production process, and only a few products, such as water heater and water dispenser linings, do not need to be polished. Therefore, the raw material is required to have good polishing properties.

Heat Resistance Heat resistance refers to the ability of stainless steel to maintain its excellent physical and mechanical properties at high temperatures.

The main factors affecting polishing performance are as follows:

Surface defects of raw materials, such as scratches, pitting, excessive pickling, etc.

Raw material quality problems. If the hardness is too low, it is not easy to polish, and the hardness is too low, the surface is prone to orange peel when drawing.

For deep-drawn products, small black spots and wrinkles will appear on the surface of the area with large deformation, which will affect the performance of BQ.

Stainless steel material:

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 is 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 weak media such as atmosphere and water and oxidizing media such as nitric acid increases with the increase of chromium content in steel, and 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.

Stainless steel materials include: stainless steel strip, stainless steel rod, stainless steel plate, stainless steel wire, stainless steel pipe, product grades: SUS310S, 316L L, etc.;

In a wide range of industrial applications, stainless steel offers satisfactory corrosion resistance. According to the experience of use, in addition to mechanical failure, the corrosion of stainless steel is mainly manifested in: a serious form of corrosion of stainless steel is local corrosion (that is, stress corrosion cracking, pitting corrosion, intergranular corrosion, corrosion fatigue and crevice corrosion).

These localized corrosion accounts for more than half of the failures. In fact, many failures can be avoided through the proper selection of materials.

Stainless steel is a corrosion-resistant, high-temperature resistant alloy and belongs to alloy metal materials. It is not easy to rust because stainless steel contains chromium, nickel, aluminum, and silicon in addition to iron. After adding chromium and other elements to the steel, the structure of the steel can be made more uniform, thereby changing the properties of the steel, making it difficult to invade corrosive substances, and the surface of the stainless steel is attached to a wax loss layer oxide protective film, which is naturally difficult to rust.

2. What are the types of stainless steel materials?

1. Ferritic stainless steel.

Ferritic stainless steel, one of the most common stainless steel materials, is a type of stainless steel that has a ferritic structure in use. This stainless steel has a chromium content of between 11% and 30%. In addition, it also contains small amounts of molybdenum, titanium, niobium and other elements.

In addition to good corrosion resistance, ferritic stainless steel also has good oxidation resistance, excellent stress resistance, good thermal conductivity and a very small coefficient of expansion. However, ferritic stainless steel has poor plasticity, so this stainless steel material is mainly used to make corrosion-resistant parts.

2. Austenitic stainless steel.

Austenitic stainless steel is a stainless steel with a stable austenitic structure, containing 18% chromium and 8% nickel, and also contains small amounts of molybdenum, titanium, nitrogen and other elements. This stainless steel material is a product with good comprehensive properties, which can resist the corrosion of various media. Moreover, austenitic stainless steel has good toughness and plasticity, and its easy-to-cut air-to-air performance is also very good.

At present, austenitic stainless steels are widely used in various industries.

3. Martensitic stainless steel.

Martensitic stainless steel is a hardenable stainless steel material. The biggest feature of this stainless steel material is that its mechanical properties can be changed by heat treatment. At present, this stainless steel material is mainly used for the processing of steam turbine blades, surgical instruments and other products.

Stainless steel is an anti-corrosion and high-temperature resistant alloy, and it is not easy to rust, which has a lot to do with its composition. In addition to iron, stainless steel is composed of chromium, nickel, aluminum, and silicon. After adding chromium and other elements to the steel, it can make the structure of the steel more uniform, thereby changing the properties of the steel, so that the corrosion invasion becomes difficult, and the surface of the stainless steel is attached with an oxide protective film, just like putting on a piece of armor for the steel, it is naturally not easy to rust.

The first to realize the corrosion resistance of stainless steel were two German scientists, Monatz and Borst. Monatz received a patent for the production of stainless steel in Germany in 1911. However, when it comes to the real inventor of stainless steel, Monatz seems to be no match for the British metallurgist Henry Brelley.

During the First World War, Brelley was commissioned by the British ** Military Arsenal to study the improvement work of **. At that time, a large number of guns were needed for war, but due to the limitations of technical conditions, the rifles used by soldiers were extremely loose and easy to wear and tear, and they were prone to rust. So, Brearley wanted to invent an alloy steel that was not easy to wear and rust.

Later, he added various elements to the steel and did a number of experiments. However, many trials have not yielded the desired results. On one occasion, he incorporated chromium into the raw material for steelmaking, and when the new material came out, it had a shiny and attractive appearance.

He happily made this steel into the barrel. It's a pity that this steel texture was too brittle, and in the first shooting tests, it was "crushed".

Brearley found in the rusted scrap metal pile, most of which was rusted, and only a few pieces of steel pipe fragments doped with chromium were still shiny. This discovery surprised Brearley, and he hurriedly retrieved these "treasures" to study in detail.

Henry Brelley found that these hollow bent chrome steels are not easy to cast even in the sun and rain, and they are not "afraid" of acid and alkali like ordinary steel. Because chrome steel was too brittle and expensive to make gun barrels, Brearley introduced this non-rusty steel to a cutlery factory to produce a variety of stainless steel knives, forks, etc., which made stainless steel a sensation in Europe. In 1916, Brelley patented stainless steel, and people respected him as the "father of stainless steel".

Since then, many inventors have also made important contributions. French scientists Guillet and Portevin invented high-temperature, earthquake-resistant austenitic stainless steel, which is used in the food industry. 1911 In 1914, Danzi of the United States invented another major category of stainless steel - ferritic stainless steel.

Now, stainless steel has developed into a large family of alloys, with no less than hundreds of varieties.

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. 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. There are two kinds of stainless steel: ordinary (general) stainless steel and corrosion-resistant steel: steel that can resist erosion in air or weak medium can be called stainless steel, that is, general stainless steel; Steel that resists erosion in certain strong corrosive media is called corrosion-resistant steel.

Stainless steel is not necessarily corrosion-resistant, and corrosion-resistant steel certainly does not rust, and of course it is worthy of the title of stainless steel. Stainless steel not only has strong chemical stability, but also has sufficient strength and plasticity, and has stable mechanical properties at a certain high or low temperature.