Automatic estimation of the carbon and silicon content of molten cast irons using microprocessor-based instrumentation

The paper describes the principles of operation of a microprocessor-based instrument designed for use in the foundry industry. The instrument automatically determines the carbon and silicon content of molten cast irons by monitoring the cooling profile of a sample in a mould which contains a quantity of tellurium. The liquidus arrest temperature and solidus arrest temperature of the cooling profile of such a sample of unalloyed cast iron are related to the carbon and silicon content of the metal. Manipulation of the data produces an estimate of the carbon content of the molten metal to within 0.1% and, under certain circumstances, an estimate of the silicon content to within 0.14%. The automation of this process has resulted in high reliability of results, reduction in calculation time and elimination of subjective error present in manual analysis methods.