1. Ferritic stainless steel
Chromium content is 15%~30%. Its corrosion resistance, toughness and weldability increase with the increase of chromium content. Its chloride stress corrosion resistance is superior to other types of stainless steel. With high chromium content, its corrosion resistance and oxidation resistance are relatively good, but its mechanical and technological properties are poor. It is mostly used for acid resistant structures with little stress and as oxidation resistant steel.
Application: It is used for nitric acid and food factory equipment, and can also be used to make parts working under high temperature, such as gas turbine parts.
2. Austenitic stainless steel
Chromium content is more 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 various mediums. Common grades of austenitic stainless steel include 1Cr18Ni9, 0Cr19Ni9, etc. This kind of steel has good plasticity, toughness, weldability, corrosion resistance and non-magnetic or weak magnetic properties. It has good corrosion resistance in oxidizing and reducing media.
Application: It is used to make acid resistant equipment, such as corrosion resistant containers and equipment linings, delivery pipes, nitric acid resistant equipment parts, etc., and can also be used as the main material of stainless steel clock accessories.
3. Austenitic ferritic duplex stainless steel
A stainless steel in which the austenite and ferrite structures account for about half of each other. It has higher plasticity and toughness, no room temperature brittleness, significantly improved intergranular corrosion resistance and welding performance, while maintaining the 475 ℃ brittleness of ferritic stainless steel, high thermal conductivity, superplasticity and other characteristics.
Application: Its superior mechanical and corrosion resistance properties have won the favor of users, and it has become an excellent corrosion resistant engineering material that can save both weight and investment.
4. Precipitation hardening stainless steel
The matrix is austenitic or martensitic, and the common grades of precipitation hardening stainless steel are 04Cr13Ni8Mo2Al, etc. Stainless steel that can be hardened (strengthened) by precipitation hardening (also known as age hardening).
Application: Widely used in cutting-edge industry and civil industry, such as typical precipitation hardening stainless steel 17-4P, which can be used to make structures with corrosion resistance, wear resistance and high strength below 370 ℃
5. Martensitic stainless steel
High strength, but poor plasticity and weldability. The common brands of martensitic stainless steel are 1Cr13, 3Cr13, etc. Because of its high carbon content, it has high strength, hardness and wear resistance, but its corrosion resistance is slightly poor.
Purpose: It is used for some parts with high mechanical property requirements and general corrosion resistance requirements, such as springs, turbine blades, hydraulic valves, etc. This kind of steel is used after quenching and tempering. Annealing is required after forging and stamping.
6. Stainless steel plates and strips for pressure equipment
The classification and code, size, shape and allowable deviation, technical requirements, test methods, inspection rules, packaging, marks and product quality certificates of stainless steel for pressure vessels have clear requirements. Common brands include 06Cr19Ni10, 022Cr17Ni12Mo2, and the number code is S30408, S31603, etc.
Application: Mainly used for food machinery, pharmaceutical machinery and other sanitary equipment.
