Introduction
Heat-resistant cast iron is a kind of cast iron which has great oxidation resistance, thermal shock resistance and corrosion resistance. It is mainly composed of graphite and iron-chromium-aluminum-silicon elements, with high chromium content, which can significantly improve the oxidation resistance and corrosion resistance of cast iron. There are many different grades of heat-resistant cast iron, each grade having different properties and material characteristics, including hardness, strength and chemical composition.
Types of Heat-Resistant Cast Iron
Heat-resistant cast iron is divided into ordinary heat-resistant cast iron and high temperature heat-resistant cast iron according to its application temperature range. Ordinary heat-resistant cast iron and high temperature heat-resistant cast iron refer to gray cast iron and low alloy white cast iron respectively. The typical grades are HT200, HT250, HT300 and HT350.
HT200 is an ordinary heat-resistant cast iron, with a carbon content of 3.2% to 3.8%, silicon content of 1.9% to 2.5%, manganese content of 0.4% to 0.7%, and chromium content of 0.3% to 0.5%. Its application temperature is up to 400℃.
HT250 is an ordinary heat-resistant cast iron, it has a carbon content of 2.7% to 3.5%, silicon content of 2.2% to 2.5%, manganese content of 0.4% to 0.7%, and chromium content of 0.4% to 0.7%. Its application temperature is up to 450℃.
HT300 is an ordinary heat-resistant cast iron, it has a carbon content of 2.2% to 3.2%, silicon content of 2.2% to 2.6%, manganese content of 0.3% to 0.7%, and chromium content of 0.5% to 0.9%. Its application temperature is up to 500℃.
HT350 is an ordinary heat-resistant cast iron, it has a carbon content of 2.2% to 3.0%, silicon content of 2.3% to 2.7%, manganese content of 0.3% to 0.7%, and chromium content of 0.6% to 1.2%. Its application temperature is up to 550℃.
Properties of Heat-Resistant Cast Iron
Heat-resistant cast iron has high strength and good thermal shock resistance, and its heat-resistant temperature is high, which can be used for metal molds under high temperature. The mechanical properties of heat-resistant cast iron are different in the temperature range from room temperature to melt temperature, and its oxidation resistance and corrosion resistance are also high.
Conclusion
Heat-resistant cast iron is widely used as a material for metal molds under high temperature, and its main structure components are iron-chromium-aluminum-silicon. There are four grades of heat-resistant cast iron, HT200, HT250, HT300 and HT350. Each grade has different chemical composition and different material characteristics including hardness, strength, corrosion resistance and oxidation resistance.
