According to the rule of invar, previously proposed by one of the writers, measurment was undertaken of the thermal expansion of binary alloys of iron and platinum, with the result that the alloys containing 52.5_??_53.5 percent of platinum have a negative coefficient of thermal expansion in a wide range of temperature, and that the smallest value of the mean linear coefficient in the temprature range 0_??_40° is -12.5×10-6 for the alloy containing 53 percent of platinum.

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Some experiments were carried out, concerning the effects of treating conditions which control the recrystallization texture. Namely, the effects of annealing temperature, annealing time and rolling temperature were studied attending chiefly to the texture of type (110) [001]; rolled plates of pure iron, silicon steel and Alfer alloy being used for samples. The following results were obtained:
(1) The type of recrystallization texture is the same, regardless of the degrees of annealing temperature, annealing time, heating velocity, etc., providing that the temperature and time of annealing have a certain lower limit for recrystallization.
(2) The texture of type (110) [001] is not seen in the rolled material, but it appears on the proper annealing.
(3) For the immanency of type (110) [001], the degree of rolling must be severe to some extent. Judging from this fact, at the high temperature rolling, there seems to exist a certain higher limit to the rolling temperature for this purpose.

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The reduction equilibrium of molten lead sulphide by hydrogen was investigated by means of the statical method, and from the results obtained, it was concluded that PbS dissolves in lead as an ideal solution.

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Some pysical properties of Selenium were measured, such as thermal expansion coefficient, specific heat, specific weight, vapor pressure, latent heat of vaporization, melting point, boiling point and electrical resistance. The electrical resistance of metallic Se at room temperature varies with the condition of heat treatment. When it is heated at constant temperature, its specific resistance decreases with the time of heating. It finally reaches to a minimum value. This minimum value is small when the temperature of heat treatment is high. The electrical resistance decreases by increasing temperature up to about 140° and then it increases with the temperature.

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Westudied the rapid annealing method by utilizing the isothermal transformation on various kinds of special steels. We also compared it with the normal annealing method (furnace cooling). As a result we found that when the isothermal transformation was applied, steels were softened very rapidly, and were able to be prevented perfectly from quenching crack. The operating times were shortened, and the degree of utilization of furnace increased. We, therefore, made the efficiency of work progressive compared with the normal annealing method.

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This research is made on stainless steels of the Ni-Cr-Mn system, alloying quantity of nikel less than the 18/8 austenitic stainless steel. This is not inferior to the typical 18/8 S. S. not only in the mechanical and physical properties, but atso in the chemical one, especially in corrosion resistance.
In this study the first step is to obtain the alloys which possess necessary mechanical and physical properties, from a metallurgic stand point.
The latter step is to improve the corrossion resistance of the said alloys. From the study, we were successful in obtaining a suitable alloy.

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The activity of lead sulphide in lead containing steel was investigated thermodynamicaly by means of the calculation of the experimental data of the reduction equilibria, FeS (in l Fe)+H₂=Fe (l)+H₂S and PbS (in l Pb)+H₂=Pb (l)+H₂S.

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It was pointed out that the heating rate in annealing white cast iron, Whose composition is of malleable cast iron (2.6%/C, 0.87/Si, 0.55%Mn, 0.145%P, 0.069/S), influences its graphitization phenomena remarkably, and the reason of which was discussed. The faster the heating rate to the annealing temperature is, the larger both the primary and the secondary graphitization velocity becomes. This effect can be observed in cast iron both in cast state and in quenched one; in the former case, the effect is strongly observed and in the latter weakly. When the subsequent annealing treatment is constant, slow heating to the temperature results in less graphitization amount than by rapid heating. Accordingly, less graphitization amount may be observed even when the total heating time is longer, which is caused by slow heating. Furthermore, it must be noted that rapid heating of the white cast iron results in the production of smaller and numerous graphite particles.
The above phenomenon is similar to the recrystallisation phenomenon of plastically worked metals by heating, althongh the two phenomena are quite different in their natures.
The quenching degree of the white cast iron may be considered to correspond to the working degree, and the graphite particle size to the recrystallized grain size. The recrystallized grain size of worked metals becomes large as the heating rate is small, and vice versa. In the similar way, the graphite particle size produced by annealing the white cast iron becomes large when the heating rate is small and small when it is large. But, the higher the graphitizing temperature of the white cast iron is, the coarser the graphite particle size becomes, which is caused by the growth of cementite before graphitization begins, and it is dissimilar in this point to that the recrystallized grain size becomes finer as the recrystallizing temperature rises.
The above phenomenon leads to the following conclusion on the practice of malleable cast iron making; the so-called short annealing cycle of 15_??_20 hrs. not only makes the temperaturé reach rapidly the annealing one, but also causes the rapid heating rate itself in the cycle to accelerate the graphitization velocity. Furthermore, rapid heating increases the graphite neucleus number, hence fine graphite particles of uniform distributiorn lead to improve the toughness of castings.

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