Abstract
It is important for CO2 mould to solve the mechanism of sand adherence on steel castings. The authors made an apparatus by which the conditions at large steel castings can be given on the laboratory mould specimens and it was investigated that the effects of SiO2/Na2O ratio of sodium silicate on the critical penetrating pressure and on the depth of metal penetration in CO2 mould.
The following results were obtained:
1) The optimum region of SiO2/Na2O ratio of sodium silicate is found to be 2.3∼2.7 at 1070mm ferrostatic pressure.
2) The increase of sodium silicate content to CO2 mould tends to result in the high penetrating pressure and decreased the depth of metal penetration throughout the mole ratio.
3) In the case of CO2 mould using sodium silicate of high mole ratio, remarkable penetrations were observed inspite of relatively high penetrating pressure.
