Stainless steel is often divided into the organization: Martensitic Steel, ferritic Steel, austenitic steel, austenitic-ferrite (duplex) stainless steel and precipitation hardening stainless steel. In addition, the ingredients can be divided into: chromium stainless steel, chromium-nickel stainless steel and chromium-manganese-nitrogen stainless steel. There are also special stainless steel steel plate and strip for pressure vessel used in gb24511_2009_ bearing equipment.
Ferritic Stainless Steel
Chromium-containing $number. Its corrosion resistance, toughness and solderability with the increase in chromium content increased, corrosion-resistant chloride corrosion resistance is superior to other types of stainless steel, belonging to this category has Crl7, Cr17mo2ti, Cr25, Cr25mo3ti, Cr28 and so on. Ferritic stainless steel Because of high chromium content, corrosion resistance and anti-oxidation performance is better, but the mechanical properties and process performance is poor, more for the resistance to acid structure and the use of anti-oxidation steel. This kind of steel can resist the corrosion of atmosphere, nitric acid and brine solution, and has the characteristics of good oxidation resistance and small thermal expansion coefficient, which can be used in nitric acid and food factory equipment, as well as parts such as gas turbine parts for working at high temperature.
Austenitic stainless Steel
Chromium containing more than 18%, but also contains about 8% of nickel and a small amount of molybdenum, titanium, nitrogen and other elements. Good comprehensive performance, can withstand a variety of media corrosion. Austenitic stainless steel commonly used brands have 1cr18ni9, 0cr19ni9 and so on. 0cr19ni9 Steel wc<0.8%, the steel number is labeled "0". This type of steel contains a large number of NI and CR, so that the steel at room temperature under the austenite state. This kind of steel has good plasticity, toughness, weldability, corrosion resistance and non-magnetic or weak magnetism, in oxidizing and reducing medium corrosion resistance is good, used to make acid equipment, such as corrosion-resistant containers and equipment lining, conveying pipelines, nitric acid-resistant equipment parts, and can also be used as stainless steel watches jewelry main material. Austenitic stainless steel is generally used for solid-solution treatment, the steel will be heated to 1050~1150℃, then water-cooled or air-cooled to obtain Tansiango body tissue.
Austenitic-ferritic Duplex stainless Steel
Both austenite and ferritic stainless steel have the advantages and superplasticity. Austenite and Ferrite bodies
About half of the stainless steel. In the case of Lower C, CR content was 18%~28% and NI content was 3%~10%. Some steel also contains Mo, Cu, Si, Nb, Ti, N and other alloy elements. This type of steel has the characteristics of austenitic and ferritic stainless steels, compared with the ferrite, plasticity, toughness is higher, no room temperature brittleness, intergranular corrosion resistance and welding performance are significantly improved, but also maintain the ferrite stainless steel 475 ℃ brittleness and high thermal conductivity, with superplasticity and so on. Compared with austenitic stainless steel, high strength and intergranular corrosion resistance and corrosion resistance of chloride have been improved obviously. Duplex stainless steel has excellent corrosion resistance and is also a nickel stainless steel.
Precipitated hardened Stainless steel
The matrix is austenite or martensite, and the commonly used grades of stainless steel for precipitation hardening are 04cr13ni8mo2al and so on. It can be treated by precipitation hardening (also known as aging hardening) to make it hard (strong) of the stainless steel.
Martensitic Stainless Steel
High strength, but poor plasticity and weldability. The commonly used grades of martensitic stainless steel are 1cr13, 3cr13 and so on, because of high carbon content, it has a higher strength, hardness and wear resistance, but slightly worse corrosion resistance, for the mechanical properties of higher requirements, corrosion resistance of the general requirements of some parts, such as springs, steam turbine blades, hydraulic press valves. This type of steel is used after quenching and tempering treatment. Annealed after forging and stamping.
Stainless steel steel plate and steel strip for pressure equipment, stainless steel, special purpose for the classification and code, size, shape and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and product quality certificate, etc. are clearly required. Commonly used brands have 06cr19ni10, 022cr17ni12mo2 number code for: S30408, S31603 and so on. Mainly used in food machinery, pharmaceutical machinery and other health-class equipment.