1. The definition and characteristics of stainless steel
Stainless steel, as the name suggests, refers to steel with high corrosion resistance. Its main components are iron, chromium, nickel and other alloying elements, of which chromium content reaches more than 10.5%, through the formation of a dense chromium oxide film on the surface of the steel, played a role in resisting most of the chemical media erosion. Stainless steel also has good toughness, strength and plasticity, and can be formed and processed by cold working, hot working and welding processes.
2. The classification of stainless steel
Stainless steel can be classified differently according to its organizational structure, chemical composition and use. Common classification methods of stainless steel include the following:
a. Classified by organizational structure
1) Ferritic stainless steel: mainly composed of ferritic, has good plasticity and weldability, common models are 304, 316 and so on.
2) Austenitic stainless steel: mainly composed of austenite, with high strength and heat resistance, common models are 310, 321 and so on.
3) Ferritic-austenitic stainless steel: composed of ferritic and austenitic, combining the advantages of both, common models are 2205, 2507 and so on.
b. Classified by chemical composition
1) Chromium stainless steel: the main alloying element is chromium, which has good corrosion resistance and is widely used in chemical industry, Marine and other fields.
2) Nickel stainless steel: The main alloying element is nickel, which has excellent corrosion resistance and high temperature resistance, and is often used in the manufacturing of chemical equipment and the nuclear industry.
3) Molybdenum stainless steel: the main alloying element is molybdenum, with good corrosion resistance and oxidation resistance, suitable for sulfuric acid, nitric acid and other strong acid media.
c. Classified by use
1) Architectural decoration stainless steel: mainly used for indoor and outdoor decoration and architectural structure, with good weather resistance and beauty.
2) Food grade stainless steel: in line with health standards, widely used in food processing, catering and other fields.
3) Stainless steel: With antibacterial properties and good biocompatibility, it is often used in the manufacture of medical equipment such as surgical instruments and artificial joints.
d. Classification by surface
1) NO.1 Hot rolling, annealing, remove the skin after hot rolling to the specified thickness, and then annealing, remove the skin. It is usually used for industrial purposes, heat resistance, corrosion resistance, and the use of surface smoothness is not high
2) NO.2B cold rolled, bright surface is usually produced the same as 2D, but is finally finished by a surface polished roll. This is what is commonly called a cold-rolled surface, which is suitable for all purposes except deep drawing (difficult), and this surface is much easier to polish than NO.1 and NO.2D
3) BA Bright annealed surface After annealing in a controlled atmosphere furnace, the cold rolled bright surface is annealed in a controlled atmosphere furnace, which is usually hydrogen or a mixture of hydrogen and nitrogen (sometimes ammonia is used).
4) NO.4 Ordinary grinding surface, single or double sides are widely used in kitchen equipment, store counters, milk making equipment, etc., starting with coarse sand grinding, and finally using about 120 to 150 sand grains
5) NO.8 Mirror surface usually can be made of the highest reflectivity of the surface, using the smallest sand for surface polishing, this surface is mostly used in the press plate and small mirror and so on
3. The application of stainless steel
Due to its unique characteristics and diverse classification, stainless steel is widely used in various fields, the following are a few typical application areas:
1) Industrial field
In the chemical, petroleum, energy, and other industries, stainless steel is often used to manufacture vessels, piping, heat exchangers, and other equipment that must withstand high temperatures, pressures, and corrosive media.
2) Architectural field
Stainless steel has good weather resistance and aesthetics, and is widely used in architectural decoration, interior decoration, and structural materials such as bridges and columns.
3) Food processing field
Food grade stainless steel materials meet health standards and are widely used in food processing equipment, food storage containers, etc. to ensure food safety and hygiene.
4) Medical field
Stainless steel has antibacterial properties and biocompatibility, and is widely used in the manufacture of medical devices, surgical instruments, artificial joints, etc., to improve the reliability and durability of medical equipment.
SUMMARY
As an important material, stainless steel has the characteristics of corrosion resistance, aesthetics and good mechanical properties, and is widely used in industry, construction, food processing, medical and other fields. In the selection of stainless steel materials, Wuxi Jianbanghaoda Steel Co., Ltd. is a reliable partner, offering a variety of specifications and models of stainless steel materials, to provide customers with a comprehensive solution.
