Thermal conductivity of cast iron at various temperatures

Thermal conductivity of cast iron at various temperatures

Junjie Chen

Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: komcjj@gmail.com, Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China

Cast iron is a class of iron-carbon alloys with a carbon content more than 2 percent. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing. Carbon and silicon are the main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel. Cast iron tends to be brittle, except for malleable cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications and are used in pipes, machines and automotive industry parts, such as cylinder heads, cylinder blocks and gearbox cases. It is resistant to damage by oxidation but is notoriously difficult to weld. Cast iron is made from pig iron, which is the product of melting iron ore in a blast furnace. Cast iron can be made directly from the molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of the molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels.

Thermodynamic temperature (degrees kelvin), Thermal conductivity (watts per meter-kelvin)

298        55

303.2            12.8

323.2            13.3

362.2            14.3

373.2            14.5

425.2            17.3

303.2            29.5

323.2            29.7

361.2            30

373.2            30.1

427.2            31.1

353.7            48.5

376.7            48.1

418.2            46.9

429.7            47.3

431.7            46.9

447.2            46