The authors are investigating the influences of several conditions — melting and inoculating temperatures, raw materials, melting furnaces, chemical compositions and gas contents of the melt, and the kinds and additional percentages of the inoculants — on the effect of inoculation. The results obtained are as follows.
  (1) Superheating of the melt increases the tendency of stabilizing cementite. The inoculation of the melt superheated results in the uniform distribution of medium size flake graphite and also results in the matrix consisting of pearlite and fine ferrite. Therefore, the higher the melting temperature, the better effect of inoculation is obtained.
  (2) The higher the melting temperature, the more addition of inoculant is necessary for sufficient inoculation.
  (3) The higher the inoculating temperature, the more effective inoculation is carried out.
  (4) By inoculating the melt contained 0.4∼0.8 per cent phosphor, the tensile strength and transverse load are increased considerably, but the increase of transverse deflection and impact value are small.
  Small increase of toughness may be due to the fact that steaditeis not affected by inoculation.

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  High-temperature melting is indispensable for the production of high strength cast iron. The results of experiments and the theoretical investigations made on the operation for high temperature melting shall be announced in this paper and the author intends to derive the most favourable condition of such operation from those results.
  The distribution of temperature, height of bed coke, blast volume, coke ratio, composition of efluent gas were measured in the small cupola having 460 mm of inside diameter of cupola lining, and the relationship between those factors and the tapping temperatures was analized.
  The recommended practice to get the molten metal of 1530°C tapping temperature is described as follow :
[Written in non-displayable characters.].
  The molten metal attaining the required goal mentioned above was obtained when the practical operation was carried in the cupola having the inside diameter of lining 770 mm under the suggested operating conditions.
  Besides, it is earnestly desired to take good precautions not only in preparations from lighting to blast-on. but also in charging so that it may be executed in orderly fashion with constant coke size and melting stock.

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  In 4th report, the influences of moisture, ramming − energy, bentonite addition and grain size distribution upon green compressive strength in three kinds of base sands were studied and then these several combined factors having interaction were discussed. The outline of this experiment is as follows :
  1) Provided that the compressive strength per unit content of bentonite is named as the bonding efficiency (η), then the value of η is mainly due to bentonite content and grain size distribution. Namely, the base sand Ⅲ is, in general, the largest in η and in the same sand, it takes a maximum value at a constant bentonite content.
  Accordingly, the most effective bentonite content in practical use is due to the type of base sand.
  2) η is generally related to deformability |b|.
    The larger η, the larger |b|. So η, compressive strength and surface hardness can be developed by increasing |b|.

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    Among many sorts of inorganic binders for molds, the physical properties of bentonite was especially studied in this work.
    As the testing method for inorganic binders, the following two kinds of methods can be considered, i. e.
  1) Mix inorganic binders to silica sands at the proportion of actual percentages and make specimens for green or dry strength and permeability. Then give comparisons on these values taken and discuss the comparative merits of each binder.
  2) Compare the relative amount of dye-adsorption or the swelling capasity of binders.
    In this experiment, the results taken by the dye-adsorption method were compared with that of the method mentioned in paragraph 1), and the correlation of those two different methods were studied. As a resultant value of the heretofore used testing method, the value of bending strength of green sand mold specimen was taken.
    In case of methylene-blue solution is used as a dye and bentonite is used as a binder, no relative relation can be observed between green strength and the amount of the dye-adsorption.
    Therefore, two kinds of acid and direct dye materials are used instead of methylene-blue and the experiment is carried with varying dye-adsorption conditions. Judging from the results obtained, it seems that it will be impossible to express the properties of binders by the dye-adsorption method.
    This method of dye-adsorption, however, is suitable to determine the degree of deterioration of sands because of its simplicity. (H. M.)

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  The author has established the method of the segregates determination of casting constituents by the local spectrographic analysis being employed the counter electrode of pure silver having the special pointed shape.
  With this method, the segregates of Si, Mn in the cast iron rod and of Si, Mn, Mg in the spheroidal-graphite cast iron rod having the various diameters were examined.
  The results are summarized as follows :
  (1) The local segregates were found at random, and a peculier segregate existed in the vicinity of shrinkage cavity or blow hole in castings.
  (2) From the result of the local analysis on the traverse across of the diameter, the characteristic segregation curves of “V” or “W” type were drawn. (H. M.)

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