Stainless steel beer barrel stainless steel
Release date:2017-08-06 Author:YantaiToptech LTD. Click:
Austenitic stainless steel: stainless steel with austenite under normal temperature. With Cr about 18%, Ni 8% ~ 10% and C 0.1%, stable austenite tissue was found. The austenitic chrome-nickel stainless steel includes the famous 18cr-8ni steel and the high cr-ni series of steel that add Cr, Ni content and add Mo, Cu, Si, Nb, Ti and other elements. Austenitic stainless steel is not magnetic and has high toughness and plasticity, but the strength is low, it cannot be strengthened by phase change, it can only be strengthened through cold processing. Elements such as S, Ca, Se, Te, etc., have good machinability. In addition to the corrosion of oxidative acid, such steel can resist the corrosion of sulfuric acid, phosphoric acid and formic acid, acetic acid and urea. If the carbon content of such steel is lower than 0.03% or Ti and Ni, it can significantly improve the corrosion resistance of the steel. High - silicon austenitic stainless steel has good corrosion resistance to nitric acid. Because austenitic stainless steel has comprehensive and good comprehensive performance, it has been widely used in various industries. Ferritic stainless steel: stainless steel, mainly made of ferrite, in use. The chromium content is 11% ~ 30%, with body centered cubic crystal structure.
This kind of steel is generally not containing nickel, sometimes also contains a small amount of Mo, Ti, Nb elements, this kind of steel with heat conduction coefficient is big, small expansion coefficient, good oxidation resistance, good resistance to stress corrosion, etc, used in the manufacture of air, water vapor and water resistant and oxidizing acid corrosion of components. This kind of steel has disadvantages such as plastic difference, post-weld plasticity and corrosion resistance, so it restricts its application. The application of external refining technology (AOD or VOD) can greatly reduce the gap elements such as carbon and nitrogen, thus making this kind of steel widely used. Austenitic - ferrite dual - phase stainless steel: the austenitic and ferritic organization each about half of the stainless steel. In the case of low C, the Cr content is 18% ~ 28% and Ni content is 3% ~ 10%. Some steel also contain Mo, Cu, Si, Nb, Ti, N and other alloy elements. This kind of steel both austenite and ferrite stainless steel, the characteristics of compared with ferrite, plasticity and toughness is higher, no room temperature brittleness, intergranular corrosion resistance and welding performance were significantly increased, while maintaining a ferritic stainless steel of 475 ℃ brittleness and high thermal conductivity, has the characteristics of superplasticity. Compared with austenitic stainless steel, high strength and intergranular corrosion and chlorinated stress corrosion have been improved obviously.
Double phase stainless steel has excellent corrosion resistance and is also a kind of stainless steel. Martensitic stainless steel: stainless steel, which can be adjusted for mechanical properties by heat treatment, is a kind of hardened stainless steel. The typical brand is Cr13, such as 20Cr13, 30Cr13, 40Cr13, etc. The hardness is higher after quenching, different tempering temperature has different toughness combination, mainly used for steam turbine blade, tableware, surgical instrument. According to the difference of chemical composition, martensite stainless steel can be divided into martensitic chrome steel and martensitic chromium nickel steel. According to the different organization and strengthening mechanism, it can be divided into martensitic stainless steel, martensite and semi-austenite (or semi martensite) precipitation-hardening stainless steel and martensitic aging stainless steel. On behalf of the steel grade, chemical composition, mechanical properties at room temperature, the representative of the martensitic stainless steel grade 12 cr13, 20 cr13, 30 cr13, etc., is the representative of the ferritic stainless steel grade 10 cr17, 10 cr17mo, such as the representative of the austenitic stainless steel grade for 06 cr19ni10 (304), 022 cr19ni10 (304 l), 06 cr17ni12mo2 (316), 022 cr17ni12mo2 (316 l), 06 cr18ni11ti (321), 06 cr18ni11nb (347), the representative of the duplex stainless steel grade for 00 cr26ni7mo2ti, etc.
Will appear during the manufacture of the stainless steel equipment damage, defects and some influence on the surface of the material, such as: dust, iron powder or embedded iron, hot temper color and other oxidation layer, rusty spot, grinding burrs, arc welding spot, welding spatter, welding flux, welding defects, oil and grease, residual adhesive and paint, chalk and marker and printing, and so on. The vast majority are ignoring their harmful effects and not paying attention or doing badly. However, they are potentially harmful to the protective coating. Once the protective film is damaged, it is reduced or altered by other means, and the stainless steel below will begin to corrode. Corrosion generally does not spread across the surface, but in defects or around them. This kind of local corrosion is usually corroded by pitting or crevice, which can develop in depth and breadth, while most surfaces are not eroded.