Stainless steel is a kind of high alloy steel that can resist corrosion. With a beautiful surface, do not have to go through plating or paint and other surface treatment, so many machinery factories to show themselves is stainless steel, often do not do any paint treatment, stainless steel has a beautiful appearance, corrosion resistance characteristics, not easy to damage and other advantages, widely used in all walks of life.

Stainless steel can be roughly divided into 200 series, 300 series and 400 series three categories, of which 300 series is the most commonly used, 200 series and 400 series is a certain way of 300 series of substitutes, and strictly speaking, 400 series is not called stainless steel, called stainless iron, because it does not contain nickel elements, so magnets can be attracted. The 200 series and 300 series have nickel, so they are not magnetic and cannot absorb iron.

304 is the most common variety in the 300 series, so the price change of 304 can generally determine the price trend of the entire stainless steel. The 200 series contains less nickel, the 400 series does not contain nickel, and the 300 series contains the most nickel, so the 300 series is the most affected by the nickel price. 300 series can be simply divided into 304, 304L, 316, 316L, 321, 309S, 310S, etc., the distinction is based on the different content of various metal elements, the characteristics of stainless steel with different content are not the same, the difference between 304 and 304L is the difference in carbon (C) content, with L is said to contain low carbon, also called low carbon, The difference between 316 and 316L is the same.

Stainless steel can be divided into five categories: coil, plate, profile, steel pipe and parts, and the most important is coil and plate. Profiles are all kinds of materials made of different shapes of plates, including Angle steel, flat steel, I-steel and channel steel. Steel pipe mainly refers to seamless steel pipe, and the opposite of seamless steel pipe is welded pipe, the difference is whether it is formed at a time. Parts mainly refer to elbows and flanges and other small things. The coil and the plate are actually the same, the factory form is not the same, the coil is a roll, the plate is a sheet, if the factory is the plate, also known as the original plate, generally thick plate, because it is very thick, it can not be rolled, generally more than 16 mm can not be rolled.

304, as a widely used steel, has good corrosion resistance, heat resistance, low temperature strength and mechanical properties, stamping, bending and other hot processing properties, no heat treatment hardening phenomenon, non-magnetic, the use of temperature from minus 193 degrees to positive 800 degrees. Uses: tableware, kitchenware, water heater, boiler, auto parts, medical equipment, food machinery, wine storage, pressure vessel (chemical machinery, chemical equipment). 304L as a low-carbon 304 steel, in the general state, corrosion resistance and 304 is about the same, but after welding and stress relief, it has good resistance to intercrystalline corrosion, in the case of no heat treatment, it can also maintain good corrosion resistance, generally used at 400 degrees, the use is petrochemical industry, building materials.

321 Add Ti element to 304 steel to prevent intercrystalline corrosion, suitable for positive 430 to 900 degrees below, non-magnetic; Use: automotive exhaust, heat exchangers, containers and other products that are not heat treated after welding are not suitable for making food processing equipment due to the addition of Ti elements. 316 Low carbon, add MO element, so his corrosion resistance and atmospheric corrosion resistance and high temperature strength performance is particularly good, can be used under harsh conditions, suitable for use below 900 degrees, non-magnetic. Uses: Equipment used in seawater, chemical, dye, paper, acetic acid, fertilizer and other production equipment, food industry and coastal facilities, products with special requirements against intercrystalline corrosion.

309S/310S these two materials, nickel and chromium content is relatively high, while increasing the content of Si, so that it has high temperature and corrosion resistance, of which 309S can withstand repeated heating below 980, 310S use temperature reaches 1200 degrees, continuous use temperature can be 1150 degrees, non-magnetic. Application: Suitable for high temperature electric furnace equipment, drying equipment and other key parts, furnace materials, aviation, petrochemical, electric power and so on. The 200 series is similar to the 304 and is cheap and economical. Uses: Food processing utensils, kitchen equipment, food processing equipment, filters, milk cans, consumer durables, washing machine accessories, water heaters, steel furniture, architectural decoration, decoration. In terms of fatigue resistance, 201 hardness is larger, toughness is not as good as 304, or 304 fatigue resistance is better.