Determination of Oxygen in Cast Iron

Recently, the determination of oxygen in cast iron has been required and it is important to determine not only the total amount of oxygen but also the oxygen in each oxide. The non-metallic inclusion method is usually used for determing each oxide in cast iron, which, however, is tedious and not reliable. Hence, the fractional vacuum fusion method was studied, and it was found that by using a tin-bath, FeO could be extracted at 1050℃, MnO at 1150℃, SiO_2 at 1450℃ and Al_2O_3 at 1750℃ by this simple method. For comparison, samples of the same cast iron were also analyzed by the hot nitric acid method, the chlorine method and the electrolytic method, and satisfactory results were obtained by the fractional vacuum fusion method in comparison with the case of the non-metallic inclusion method