Abstract
A study was made on sampling of cast iron for accurate analysis by the use of the Quantovac.A sample cast in a“mushroom”type mould was proved to have the most uniform structure and to give the best analytical result.
Sampling position in the ladle is found to significantly affect the Quantovac values of Mg and S, and also the result of chemical analysis of C.
In the case of large concentration of C, the Quantovac value of C exceeds its chemical value with increase of precipitation of kish graphite which is inevitable in super eutectic cast iron.To overcome this problem, we studied two methods, one of which was to add a chill-promoting element to the molten metal, and the other, to use correction curves which were statistically determined to coincide the Quantovac value with the chemical value.While the former is applicable only to some plain case iron, the latter can be applied for any kind of cast iron with a carbon content up to 4.20%.
