Heat-resistant steel with austenite matrix. This type of steel contains a large amount of austenite-forming elements such as nickel, manganese, and nitrogen. It has good high-temperature strength and structural stability above 600℃ and good welding performance. It is the most widely used type of heat-resistant steel at 600-1200℃.
According to its alloy element composition, it can be divided into different series such as chromium-nickel, chromium-nickel-nitrogen, chromium-manganese-nickel-nitrogen, chromium-manganese-nitrogen, iron-manganese-aluminum, etc.:
(1) Chromium-nickel series. It is the most widely used and most graded series of this type of steel. With its different chromium and nickel content ratios, it meets the needs of different temperature grades. With the increase of chromium and nickel content, the oxidation resistance and high-temperature strength increase accordingly. Solid solution strengthening elements (tungsten, molybdenum), carbide-forming elements (vanadium, niobium, titanium) and trace elements (boron, zirconium, magnesium, rare earth, etc.) are added to the steel as needed to further improve the thermal strength of the steel.
(2) Chromium-nickel-nitrogen series. In order to save nickel and improve the high temperature strength of steel, nitrogen is added to the steel.
(3) Chromium-manganese-nickel-nitrogen and chromium-manganese-nitrogen. Adding manganese and nitrogen to steel at the same time can save a lot of nickel. On this basis, adding tungsten, molybdenum, vanadium and niobium can further improve the high temperature strength. It is used for exhaust valves that bear greater loads and has good oxidation resistance and carburization resistance. It can be used as a hanging bracket, carburizing furnace internal components, heating furnace conveyor belt, material tray, etc. Compared with chromium-nickel steel, chromium-manganese-nitrogen and chromium-manganese-nickel-nitrogen steels have higher strength, but because more manganese is added to the steel, it has an adverse effect on high temperature oxidation resistance, and the oxidation resistance is not as good as chromium-nickel heat-resistant steel.
Seamless hollow pipe
