Explanation

alloy cast iron with oxidation resistance at high temperature, which can ensure certain high temperature strength and creep resistance. According to the types of alloy elements added, it can be divided into: low chromium cast iron (chromium content 1.5% to 3%), medium silicon cast iron (silicon content 3.5% to 5.5%, with stable ferrite structure), high chromium heat resistant cast iron (chromium content 15% to 18%), high aluminum heat resistant cast iron (aluminum content 20% to 24%), etc. The main mechanisms of improving the heat resistance of cast iron include the following aspects: adding elements that can form stable and dense oxide films, such as Si, C, Al, etc; Reduce the content of graphite or improve the shape of graphite to reduce the passage of oxidizing gas; Add strengthening matrix elements, such as O, Mo, Nb, V, etc. Heat resistant cast iron (GB/T9437-2009) is widely used in heating furnace bottom plate, hanging beam, furnace rod, crucible, carburizing tank, boiler accessories, reaction kettle, etc. It can withstand the high temperature environment below 1100 ℃ under high temperature and is used to manufacture various castings.

Classification