Truck-frame of rolling stock made by one block steel casting has recently been manufactured in large quantities and, as the problem on casting in relation to it, it is required in practice to clarify the tendency of deformation by shrinkage in truck-frame of rolling stock made by one block steel with reference to side-frame, transom and end beam of truck parts.
  Generally the cross-sectional thickness of truck-frame is approx. 18 mm, the weight of casting is 1,400∼2,400 kg and casting-size is approx. 4,000×2,000×800 mm. In ordinary steel casting, it was cast at the pouring temperatures of 1,520∼1,540°C and we investigated the deformation of itsas-cast state and that of after annealing.
  Casting chart of truck-frame is shown in Fig. 1 and we used green mould assembled cores. The complete product of a truck-frame is shown in Photo. 1. The results investigated the tendency of shrinkage deformation of this truck-frame are illustrated in Figs. 2∼4.
  The built up truck-frame, not one block steel casting, is shown in Photo. 2, and as for a parts of which, the side-frame, is shown in Photo. 3. The same tendency of deformation shown in Fig. 5 can be observed and such a tendency can be found in the side-frame of the truck-frame made by one block steel casting because of the resemblance of casting condition. A tendency of deformation in side-frame as the parts, is shown in Fig. 6.
  The followings can be derived from the investigation.
 (1) If the casting condition is almost similar, we can presume that the shrinkage deformation of one block casting in some degree from the shrinkage deformation condition of the independent steel casting which consists of each part of the casting, and such a case like this, general rules of shrinkage deformation of casting and experiences are very useful for us.
 (2) We found less resistance of casting mould against shrinkage deformation, less occurrence of cracks and much deformaton, in a green sand mould assembled with many cores than in dry sand mould.
 (3) Knowing that a tendency of shrinkagedeformation and its deformation quantity, we can decide measuring scale in accordance with each part and after doing so, combining various measuring scales suitably, we can limit the deformation quantity within the range of tolerances.
  These matters are so noteworthy points that we can apply them largely in order to get the products of less cracks and of less shrinkage deformation in case of manufacturing one block steel casting hereafter.

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  Using a midget cupola, performances and effects of various sizes of cylindrical shaped tuyères have been investigated. The results obtained are as follows :-
  1) When the size of tuyère is decreased, melting rate of metal or combustion rate of coke is decreased and tapping temperature is increased. But these results should be ascertained by further experimentation.
  2) Chemical composition of molten metals is not affected much influence by the size of tuyère. But when too large or too small tuyères are used, depth of chill test is slightly increased.
  3) It seems that CO₂ per cent of effluent gases does not give much influence by the size of tuyère. When the size of tuyère, however, is too small, it affects to some extent.
  4) The temperature distribution in furnace is affected by the size of tuyère, but much study should be performed for further information.
  5) Pressure drop at tuyère (P₁) has the following relations with average wind velocity at the said tuyère (w_α) :
        w_α=C√2P₁/ρ
where C is a constant which is smaller than 1, and ρ is density of the air.
  6) Pressure drop (P₂) at furnace shaft, which is filled with unburned coke, is expressed as follows :
        P₂=kQ²
where k is a constant and Q is blast volume per minute.
  But when coke is burned, it seems that the relation between pressure drop (P₃) at shaft and blast volume is somewhat complicated.
  7) Pressure distribution in furnace is principally decided by the temperature distribution in furnace and blast volume, but when the size of tuyère is small, the pressure at tuyère level becomes higher to some extent by the accumulation of pressure.

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  A comparison is made between Chita coast sand and silica sand produced by conical mill, on the properties such as chemical analysis, grain fineness, grain shape, properties after milling, tendency to burning-on, refractoriness and expansion.
  Description is given of practical applications of these sands as facing sand in green sand mould for steel casting.

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  The author has studied the welding phenomena between molten brass (4 : 6 Brass) and solid brasses having various concentrations of Zn, (0, 10, 20, 30, 40%) and has obtained the result similar to the case of welding between cast iron and steel.
  Namely, the degree of melting point of solid metal does not give any infiuences on welding or joining, therefore, regardless of the sorts of Cu alloys ; i. e, pure Cu or 4 : 6 brass, welding is completed under the same thermal condition.
  This will give us the suggestion that the welding phenomena is not occured due to the melting of solid surface but the intermetallic diffusion.

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