The ferrite elements, such as chromium, aluminum and silicon, can promote the formation of a dense oxide film on the metal surface at high temperature to prevent further oxidation, which is the main element to improve the oxidation resistance of steel and resistance to high-temperature gas corrosion. But the high content of aluminum and silicon will worsen the room temperature plasticity and thermoplasticity seriously. Chromium can significantly increase the recrystallization temperature of low alloy steel, and the strengthening effect is the best when the content is 2%.
Nickel and manganese can form and stabilize austenite. Nickel can improve the high temperature strength and carburizing resistance of austenitic steel. Although manganese can replace nickel to form austenite, it damages the oxidation resistance of heat resistant steel.Stainless Steel Material Welding Electrode E308 16
Vanadium, titanium and niobium are strong carbide forming elements, which can form fine dispersed carbides and improve the high temperature strength of steel. The combination of titanium and niobium with carbon can also prevent the intercrystalline corrosion of austenitic steel at high temperature or after welding.
Carbon and nitrogen can expand and stabilize austenite, thus improving the high-temperature strength of heat-resistant steel. When there are more chromium and manganese in steel, the solubility of nitrogen can be improved significantly, and nitrogen alloying can be used instead of nickel which is more expensive.
Boron and rare earth are trace elements in heat - resistant steel. Boron melting into solid solution causes crystal lattice distortion, and boron at grain boundary can prevent element diffusion and grain boundary migration, so as to improve the high temperature strength of steel. Rare earth elements can significantly improve the oxidation resistance and thermoplasticity of steel.
Heat resistant steel is often used in the manufacture of boilers, steam turbines, power machines, industrial furnaces and parts that work at high temperatures in industrial sectors such as aviation and petrochemicals. In addition to the requirements of high temperature strength and resistance to high temperature oxidation corrosion, according to the different uses also require adequate toughness, good machinability and weldability, as well as a certain degree of structural stability. China has been producing heat-resistant steel since 1952. In the future, some new low alloy hot strength steels are developed, so that the working temperature of pearlite hot strength steels is increased to 600 ~ 620℃. In addition, a number of new low cr/Ni oxidation resistant steels have been developed.Materials Steel Sheet Roofing Suppliers Stone Coated Metal Roofing Sheet Soundproof
Use of heat resistant steel
Heat-resistant steel and stainless acid-resistant steel cross each other in the range of use. Some stainless steels have heat-resistant steel characteristics and can be used as both acid-resistant and heat-resistant steel.Prime Quality Cheap Price 201 304 Stainless Steel Coil Pipe