Mathematical figures relating to the demand and supply of scrap iron is not touched in the present lecture because the publishing of figures during time of emergencies is prohbited. It is however a distinct fact that simple open-hearth furnace plants or electricfurnace plants which chiefly use imported scrap have been put to a great deal of inconvenience due to the insufficient supply of scrap. Although it seems to be out of mark to deal with such problem without the numerical figures, some technical points alone may be considered herewith.
Since the scarcity of scrap is becoming increasingly pronounced, the problems of whether consumption should be restricted and redwced, and how substitute materials to meet the shortage could be secured, should be primarily considered. The simple open-hearth furnace and electric-furnace which need scrap iron are used for high quality steel and most of the machinery steels for munition industry depend on them. It is therefore most urgent to supply sufficient scrap of good quality or its substitute at a favorable speed.
For the substitute for the scrap used in the simple open-hearth furnace, it is recommended to use the greater part of Bessemer steel derived from the blast furnace together with the sinall part of Luppe from the rotary furnace, from the standpoiht of quanlity and quality. For the substitute for use in the acid open hearth.furnace, the so-called "refined steel" derived from the basic open hearth furnace is recommended. For the substitute for use in the electric furnace, some mixtures of the Bessemer. steel and Luppe are suitable for manufacturing steel castings and structures. For the material for high quality steels as long as rich ores with especially little impurities are available, the use of sponge iron derived from Wieberg's and other Processes proves better. Besides, the Heroult are furnace is the best means for treating the titanium-poor sand iron derived from the basic rocks (such as "Masago") or a pulverized rich ore with little impurities or a nickeliferous earth and the like which are found in large quantities in the South Seas All of these materials prove to be a high-quality and "high-virginity" subtitutes for scrap iron. Especially the last, as a nickel resource, is suggested to be most. significant to meet the present situation.

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In manufacturing vanadium steel by a direct steel making process from low-phosphor vanadium-bearing ores as the source material, a flux of sodium carbonate or sodium dicarbonate was used. A ddition of this flux enhanced the yield of vanadium and enabled to manufacture easily an excellent vanadium steel with the high vanadium content.

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The pyrite cinder with the decreased copper and sulphur content may be obtained either by sizing or floatation. The alternative should be decided in the following way:
(1) Sizing is preferred in ease of tlhe presence of much roasting kernels.
(2) Floatation is preferred in case of the absence of roasting kernels.

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A method was developed which is improved from the Herty Process and capable of determining the oxygen content in the molten steel in 15 minutes. Some minutes are required to separate carbides in case where the specimen contains more than 1% C and 1% Cr. But still it presumably meets the purpose because of the capability of determination within 25 minutes. Besides, various preparatory tests were conducted during the course of the present experiment and, consequently, it was recognized that the error happened in the analysis lies within the order of the experimental errors.

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During the pickling operation of steel, part of iron is dissolved into acid and evolves hydrogen. Some part of hydrogen, thus evolved, is absorbed in steel and causes many troubles during their after treatments. The author determined the effects of pickling time, temperature of acid and itS concentration on the amount of hydrogen absorbed in steel.
Specimens used were 0·3%, 0·7% and 0·9% carbon steels, of which the diameter and length were 15mm. and 50nm. respectively.
These were soaked in acid, washed, dried and then the amount of hydrogen quickly determined by the vacuum extraction method.
Following are the results obtained:-
(1) The amount of hydrogen absorbed in steel increases as the time of pickling increases, but the rate of increase gradually drops.
(2) The higher the temperature of acid, the more hydrogen is absorbed.
(3) The higher the acld concentration, the more hydrogen is absorbed at a temperature of 53°C, but scarcely any difference between concentrations of 10% and 20% is not observed at 70°C.
(4) The ratio of hydrogen absorbed to the hydrogen evolved is considerably great at the beginning of pickling, but after a few minutes this ratio decreases markedly.

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In view of inquiring into the cause of the temper-brittleness in Silzin-Bronzes and their improvement, the microscopic and mechanical tests (hardness and impact tests) were performed with some Silzin-Bronzes (Si 4%, Zn 10%) containing 1-2% respectively of Al, Mn, Sn and Fe. According to the result, the temper-brittleness was accounted for by the dccomposition of or the precipitation from the super-cooled κ-phase, which was found in the Cu-Si system and the Cu-Si-Zn system. The addition of the small amount of Al or Mn to Silzin-Bronzes showed almost no effect, while the least addition of Fe or Ni considerably spoiled the impact value, owing to the co-existence or the brittle γ-phase.

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