Stainless steel (Stainless Steel) is the abbreviation of stainless steel and acid-resistant steel.

Stainless steel that is resistant to weak corrosive media such as air, steam, and water is called stainless steel, or stainless steel; steel that is resistant to chemical corrosive media (acid, alkali, salt, etc.) is called acid-resistant steel.

Due to the difference in chemical composition of the two, their corrosion resistance is also different. Ordinary stainless steel is generally not resistant to corrosion by chemical media, while acid-resistant steel is generally not resistant to corrosion. The word "stainless steel" refers not only to a single type of stainless steel, but to more than one hundred kinds of industrial stainless steel. Each stainless steel developed has good properties in its specific field of application. The key to success is to first understand the application and then identify the correct steel grade. There are usually only six steel grades associated with building construction applications.

They all contain 17-22% chromium, and the better grades also contain nickel. Adding molybdenum can further improve atmospheric corrosion, especially corrosion resistance to chloride-containing atmospheres.

Generally speaking, the hardness of stainless steel is higher than that of aluminum alloy, and the cost of stainless steel is also higher than that of aluminum alloy.

According to the composition, it can be divided into Cr series (400 series), Cr-Ni series (300 series), Cr-Mn-Ni (200 series), heat-resistant chromium alloy steel (500 series) and precipitation hardening system (600 series).

200 series: chromium manganese nickel
201, 202, etc.: Manganese is used instead of nickel, which has poor corrosion resistance and is widely used as a cheap substitute for 300 series in China

300 series: chrome-nickel austenitic stainless steel
301: Good ductility, used for molded products. It can also be hardened by machining. Good solderability. Wear resistance and fatigue strength are better than 304 stainless steel.

302: The corrosion resistance is the same as 304, and the strength is better due to the relatively high carbon content.

303: A small amount of sulfur and phosphorus is added, which is easier to cut than 304.

304: General purpose; that is, 18/8 stainless steel. Products such as: corrosion-resistant containers, tableware, furniture, railings, medical equipment. Standard composition is 18% chromium and 8% nickel. It is a non-magnetic stainless steel whose metallographic structure cannot be changed by heat treatment. The national standard is 06Cr19Ni10.

304L: Same characteristics as 304, but with low carbon content, more corrosion resistance, easy heat treatment, but poorer mechanical properties. Suitable for welding and products that are not easy to heat treatment.

304 N: It has the same characteristics as 304 and is a nitrogen-containing stainless steel. Nitrogen is added to increase the strength of steel.

309: It has better temperature resistance than 304, and the temperature resistance can reach 980 °C.

309S: Contains a large amount of chromium and nickel, so it has good heat resistance and oxidation resistance. Products such as heat exchangers, boiler components and jet engines.

310: Excellent high temperature oxidation resistance, the maximum service temperature is 1200°C.

316: The second most widely used steel grade after 304. Mainly used in the food industry, watch jewelry, pharmaceutical industry and surgical instruments. The addition of molybdenum makes it have a special corrosion-resistant structure. Because it has better resistance to chloride corrosion than 304, it is also used as a "marine steel". SS316 is commonly used in nuclear fuel recovery units. Grade 18/10 stainless steel usually also meets this application level.

316 L: low carbon, more corrosion resistant, easy to heat treatment, products such as: chemical processing equipment, nuclear power generators, refrigerant storage tanks.

321: Except that the addition of titanium reduces the risk of material weld corrosion, other properties are similar to 304.

347: Niobium is added as a stable element, suitable for welding aircraft parts and chemical equipment.

400 series: ferritic and martensitic stainless steel, manganese-free, can replace 304 stainless steel to a certain extent
408: Good heat resistance, weak corrosion resistance, 11%Cr, 8%Ni.

409: The cheapest model (British and American), often used as a car exhaust pipe, is a ferritic stainless steel (chrome steel).

410: Martensitic (high-strength chromium steel), good wear resistance, poor corrosion resistance.

416: The addition of sulfur improves the processing performance of the material.

420: A "knife grade" martensitic steel similar to the earliest stainless steels such as Brinell high chromium steels. It is also used in scalpels and can be very bright.

430: Ferritic stainless steel, used for decoration, such as auto parts. Good formability, but poor temperature resistance and corrosion resistance.

440: High-strength cutting tool steel with slightly higher carbon content. After proper heat treatment, higher yield strength can be obtained. The hardness can reach 58HRC, which is one of the hardest stainless steels. The most common application example is "razor blades". There are three commonly used models: 440A, 440B, 440C, and 440F (easy to process).

500 series: heat resistant chromium alloy steel.

600 series: martensitic precipitation hardening stainless steel.

stainless steel mesh

Stainless steel mesh is also called stainless steel filter mesh because it is mainly used for filtering products.

Material: SUS201, 202, 302, 304, 316, 304L, 316L, 321 stainless steel wire, etc.

Weaving: plain weave, twill weave, dense weave.

Mesh: The specifications of the stainless steel wire mesh are 1 mesh to 635 mesh. The mat weaving can reach 2800 mesh.

Uses: Stainless steel mesh and other metal wire meshes are mainly used for sieving and filtering under acid-base environment conditions, oil industry mud mesh, chemical fiber industry mesh, electroplating industry pickling mesh, gas and liquid filtration, etc. for medium separation.

Mesh belt

Classified by name: stainless steel mesh belt, conveyor belt, metal conveyor belt, stainless steel conveyor belt, metal mesh belt, metal conveyor belt, stainless steel transmission belt, metal transmission mesh belt, etc.

Classification by use: Widely used in the annealing furnace mesh belt and baking furnace mesh belt in the glass product industry. Food processing industry, dehydrated vegetables, quick-frozen food single-freezing pre-treatment mesh belt, chain net. Powder metallurgy, metal heat treatment, quenching, sintering, brazing, roasting, brightening, blackening, bearings, carburizing high-temperature furnace mesh belt, baffle mesh belt, coating drying line conveyor mesh belt, foam nickel reduction production line mesh belt, Washing machine, hoist, dryer, drying machine, curing furnace mesh belt. Each conveying process uses chain nets and mesh belts.

Classified by material: 1cr13 mesh belt, 201 mesh belt, 304 mesh belt, 316 mesh belt, etc.

Classified by shape: Herringbone mesh belt, B-shaped mesh belt, diamond mesh belt, horseshoe mesh belt, chain conveyor belt, glasses-shaped mesh belt, chain plate mesh belt, spherical mesh belt

Stainless steel product expansion: stainless steel mesh belt, mesh belt, conveyor mesh belt, metal mesh belt, high temperature resistant mesh belt, Great Wall mesh belt, B-type mesh belt, stainless steel accessories. All products in the extension are made of stainless steel wire and stainless steel plate.

Magnetic

Austenite is non-magnetic or weakly magnetic, while martensite and ferrite are magnetic. After austenite is cold-worked, its structure will also transform into martensite, and its magnetism will become larger. Therefore, the method of distinguishing the quality and authenticity of stainless steel through magnet adsorption is one-sided and wrong.

stainless steel finish grade

Raw surface: NO.1 surface after heat treatment and pickling treatment after hot rolling. Generally used for cold-rolled materials, industrial tanks, chemical equipment, etc., the thickness is from 2.0MM to 8.0MM.

Blunt surface: NO.2D cold rolled and pickled after heat treatment, the material is soft, and the surface is silvery white, used for deep drawing processing, such as auto parts, water pipes, etc.

Matte surface: NO.2B is cold-rolled, heat-treated, pickled, and finished-rolled to make the surface moderately bright. Due to the smooth surface, it is easy to regrind to make the surface brighter and has a wide range of uses, such as tableware, building materials, etc. When surface treatment is used to improve mechanical properties, it can serve almost all purposes.

Coarse sand NO.3 is a product made by grinding with a No. 100-120 abrasive belt. It has better shine and discontinuous rough lines. Used for building interior and exterior decoration materials, electrical appliances and kitchen equipment, etc.

Fine sand: NO.4 is a product made by abrasive belts with a particle size of 150-180. Compared with NO.3, the glossiness is better, the coarse grains are discontinuous, and the stripes are thinner. Used in sanitary ware, building interior and exterior decoration materials, electrical products, kitchen equipment and food equipment, etc.

#320 products are sanded with 320 abrasive belts. Compared with NO.4, the gloss is better, the coarse grains are discontinuous, and the stripes are thinner. Used in sanitary ware, building interior and exterior decoration materials, electrical products, kitchen equipment and food equipment, etc.

Hairline surface HAIRLINE: HLNO.4 is a product of grinding lines produced by continuous grinding with a polishing belt of appropriate particle size (subdivision 150-320). Mainly used in architectural decoration, elevators, building doors, panels, etc.

Bright side: BA is a product obtained by bright annealing after cold rolling and leveling. Excellent surface gloss and high reflectivity. Like a mirror. Used in home appliances, mirrors, kitchen equipment, decorative materials, etc.

Application field

In architectural applications, the surface finish of stainless steel is important for a number of reasons. Corrosive environments require a smooth surface, which is less prone to fouling. The deposition of dirt will rust the stainless steel and even cause corrosion.

In spacious halls, stainless steel is the most commonly used material for elevator facing panels. Although fingerprints on the surface can be wiped off, they affect the appearance. Therefore, it is better to choose a suitable surface so as not to leave fingerprints.

Hygienic conditions are very important to many industries such as food processing, catering, brewing and chemical industry. In these applications, surfaces must be easy to clean on a daily basis, often using chemical cleaners.

Stainless steel is the best material for this. In public places, there are often scribbles on the surface of stainless steel. However, an important feature of it is that they can be washed away. This is a remarkable feature of stainless steel over aluminum. Aluminum surfaces leave marks easily and are often difficult to remove. When cleaning the surface of stainless steel, it should be carried out along the lines of stainless steel, because the lines of some surface processing are one-way.

Stainless steel is best used in hospitals or other areas where hygiene is critical, such as food processing, catering, brewing and chemical engineering. This is not only because it is easy to clean every day, and sometimes chemical cleaners are used, but also because it is not easy to breed bacteria. Tests have shown that this is the same as glass and ceramics.