In special steel castings using sand mold, the occurence of penetration largely depends upon the kinds of adding metals and simultaneously their contents.
  In this report, studies were directed towards to chromium steel and manganese steel especially. In chromium steel, in general, thin film of Cr₂O₃ is apt to produce on casting surface in mold during metal pouring. These film of Cr₂O₃ should prevent the penetration at the surface of castings.
  Therefore, it can be concluded that the higher the chromium content the less penetration occurs in chromium steel castings. While in manganese steel casting a glass composing MnO-FeO-SiO₂ is produced easily, and the penetration occurs in no relation to manganese content.

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  This experiment was done as one of the fundamental researches of cupola operation control by the effluent gas analysis.
  The cupola used is the semi-hot-blast type with 6 lower tuyeres, 6 upper tuyeres and 6 secondary tuyeres.
  The cupola was operated under constant conditions with the exception of the bed coke height : the bed coke height was changed within the range of 60∼100cm. above the upper tuyeres.
  Co₂% in the effluent gases was measured by the electrical type CO₂ indicator. The results obtained were as follows : —
  (1) CO₂% in the effluent gases is low at the beginning, but gradually increase and is fixed at some time after blast on.
  (2) The heigher the bed coke height is, the longer the time is required to fix the CO₂%.
  (3) The fixed CO₂% is nearly constant irrespective of the bed coke height when the other conditions are constant.
  (4) The heigher the bed coke height is, the longer the time does elapse to the first droplets of molten metal after blast on.
  (5) The tapping temperature is not influenced so much by the bed coke height.
  From these results we made some considerations about the melting process in the furnace.

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  Casted some cast iron and bronze arround solid aluminium bars and tested those structures, hardness and machinabilities.
  In cast iron the upper and middle parts of solid aluminium melt, the lower part does not, but in bronze all parts melt. Aluminium bars effect cast iron and bronze structures. Diffusion of aluminium into cast iron are unrecognized but diffusion of copper and tin of bronze are recognized. In cast iron combination parts of melted aluminium have some defect, but in bronze have not.

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