Abstract
In order to control Mn content in molten cast iron, the effect of Mn removal from molten cast iron by the addition of iron oxide was examined in experiments of 3kg and 100kg scale. The following results were obtained;
(1) Mn and Si contents decreased rapidly by FeO addition.
(2) Mn removal ratio was improved with increasing amount of FeO addition and decreasing silicon content in the base melt. These relationships were expressed by the following equation.
Mn removal ratio (%) ＝ FeO addition (%) × (－6 × Si content in base melt (%) ＋ 20)
(3) In the 100kg experiment, Mn content decreased from 0.6% to 0.4% by adding 4% mill scale. The mechanical property of the obtained cast iron sufficiently satisfied the standard value of FCD450 in JIS G5502.
(4) The residual oxygen after Mn removal treatment was not adequately removed by adding silicon, but was reduced to the same level of the base melt by spheroidizing treatment. However when slag existed, oxygen remained even if spheroidizing treatment was carried out.
