Heat cast iron

     Heat cast iron is an antioxidant, anti-growth properties at high temperatures, and can maintain a high strength special cast iron.

     The main requirement is heat-resistant cast iron has good resistance to oxidation and growth resistance.

     1, oxidation resistance

     The so-called oxidation resistance, heat-resistant cast iron is its resistance to the surrounding atmosphere corrosion resistance at high temperatures to work. Generally, heat-resistant cast iron at the specified operating temperature, 150h oxidation average speed does not exceed 0.5g / (m2 • h).

     2, anti-growth resistance

     The so-called anti-growth resistance is heat resistant cast iron irreversible volume grew performance at high temperature. Generally, heat-resistant cast iron at the specified operating temperature, the ability to resist 150h growth should not exceed 0.2% (mass fraction).

     Join Si, Al, Cr and other alloying elements in ordinary cast iron, cast iron can improve the heat resistance. Heat cast iron is generally divided into silicon-based heat-resistant cast iron, aluminum-based heat-resistant cast iron, cast iron and aluminum-silicon-based heat resistant chromium cast iron.

     Due to the high heat-resistant silicon cast iron, aluminum and other elements of content, therefore, somewhat less when casting fluidity, linear shrinkage larger, higher brittle transition temperature, casting often prone to cracking. So there is a certain degree of particularity in shape and off the sand clean-up process, and ordinary cast iron is different. Heat cast iron casting defects are cold cracking, porosity, graphite segregation and shrinkage and so on.