The welding phenomenon between solid steel and molton cast iron was studied from the point of physical condition in this report.
  The relation between the welding possibility and the ratio of the heat capacity which was contained in solid steel and in molten cast iron could be known quantitatively. Consequently, the physical condition, that is, the thermal condition of the welding phenomenon became clear by connecting the cooling velocity of molten cast iron with the above mentioned results.

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  During and after the World War Ⅱ, synthetic resins have been used in England and the United States for core binders and have given good results in the foundry. According to the investigations, synthetic resins offer exceptional advantages as a core binder, i. e., rapid curing, high dry strength and excellent knock-out characteristics. In this paper, the properties for the core binder of urea-formaldehyde resins are described in compared with linseed oil on the basis of some experimental results. The dry strength of urea resin sand mixed with 2.5% resin is nearly equal to that of linseed oil sand with 4.5% oil, 1300 p.s.i. Gas volume evolved when baked resin sand is rapidly heated to high temperature is less than that when oil bonded sand, but resin begins to decompose earlier than oil. Baked urea resin sand (in air) adsorpts a little more moisture than linseed oil sand. But the suitable baking temperature of resin sand is lower and the baking time is shorter than those of oil sand. It is thought that urea resin is economical and a promising core binder.

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  In the previous reports the solidification process of Fe-C alloy and the effects of Si, Al and Mg on this process were reported, and presumed these processes from the new point of view.
  In this paper the experimental results of the effects of Mn, S and Te on the solidification process of hypo-eutectic Fe-C system, are mentioned.
  From the results of the thermal analysis and the microscopic examination the following conclusions are gotten; The effects of these elements on the solidification process of Fe-C system are quite reversly from Si and Al and indicate characteristic thermal analytical curves and micro-structures as increasing of these contents.

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  It is an important problem that many handicrafts in the foundry are mechanized and efficiency is promoted. But those mechanical tools are generally apt to be so severely handled beyond their abilities that the utmost attention must be paid.
  I am about to explain the examples that electric tools such as the electric drill, portable saw, the tamper motor, coal drill motor etc., which are now sold in the market, are very useful when used with drilling and cutting of the mold and bricks, vibrating screen, feeder, belt conveyers, mixers etc.

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  If we must use copper alloy scraps to make copper alloy castings, the author will advocate the Limebabbling process which means use of calcium carbonate chips at the bottom of the molten bath.
  This process improves the mechanical properties of copper alloy which is made with scraps, that is, the tensile strength 19%, and the elongation 72%. And the content of hydrogen decreases 25%.

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  This is to report a part of the research work presently engaged to analyze the relationship between the blow hole formation and the gas evolution originated in the cores, which will also help to find the core binder bringing the least effect on the blow hole formation. The experiment has been carried out in the study of the phenomenon connected with the gas evolution from cores which were subjected to heat.
  In the experimental work, two methods have been applied. One is to use Elema furnace (1,200°C) with silica tubes (Experiment A), and the other is to use molten cast iron (1,350°C) with steel pipe (Experiment B). The measurement has been recorded in the gas evolution rate (c.c./sec) rather than in the total gas volume (c.c.). The materials applied in the testing cases were domestically produced phenolic resin, urea resins, linseed oil and phenolic resin of the U. S. product.
  No practical results have been obtained in the experiment A because of the low temperature of the furnace and the low heat conductivity of the silica tube. Experiment B brought better results, though it has yet been unable to determine which binder brought the highest effect on the blow hole formation. Up to the present it has been made clear that the U. S. phenolic resin brought the less effect on the blow hole formation than the domestic linseed oil.

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