The Fundamental Study on Chill Mould Casting Heat Transfer

In the casting process, the air-gap formation takes place at a certain time after metal pouring, and heat is transferred by radiation and conduction through a thin gas layer in the gap at the ingot-mould interface. It is a key point in the study on casting heat transfer process to make clear the air-gap formation and the solidification mechanism at the early stages of casting process. By the experiments on the lead casting with the cylindrical chill moulds, authors investigated the casting heat transfer process with numerical calculations and continuous measurements of temperatures in ingots and chill moulds, and measured the thermal expansions of the moulds. It was found that a great and sudden decrease of the heat transfer coefficient at the ingot-mould interface took place at the time when the ingot surface separated from the mould inner surface, that is, the time of the air-gap formation.