The author measured the sintering and fusing temperatures of 23 kinds of domestic iron ores. These ores were respectively crushed into fine powders of 150 mesh and small briquettes were made of each powdered ore. Heating the briquette for 2 minutes at each temperature between 1100 and 1450°C at intervals of 50°C, sintering and fusing temperatures of the ores were measured and relatively reliable results were obtained notwithstanding its extremely simple method. The results were as follows. 1) The ores of Aki, Aso, Kamaishi and Matsuo districts have relatively low fusing temperatures. and good sintering properties at relatively low temperature. 2) The ores of Ino, Tosu, Suwa, Kurohime and Akasaka districts are difficultly sintered. 3) By adding Kamaishi, Aso and Akatani ores respectively to Ino ore which is extremely infusible, the mixtures become fusible and good sintering properties are obtained.
The effects of mixing blast furnace dust, lime and blast furnace slag with each ore, on the sintering and fusing temperatures were also observed.

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Detailed physico-chemical studies have recently been made on many important phenoena occurring in the steelmaking furnace. It is, however, desirable to consider all the operations sed in the process. as a whole, in order to see whether these. operations are really necessary and iffieient in their mutual correlations.
Standing upon the standpoint mentioned above, the author analysed physico-chemically these mual correlations of the entire procedure in the open hearth process. As cxamples, data obtained from practical acid open hearth process were used.
As the result of it, it becomes clear that the open hearth process now successfully applied is nerally reasonable to remake massively steel scrap by means of melting process.
The result of these analyses will be successively reported. In this first report, the objects of the melting proccess of steelscrap are discussed.
That is:-(1) The steel bath has to contain finally standard amount of Si, Mn, C uniformly mixed l) has to have neccessary temperature, (3) its O content has to be kept in such amount as to able to be removed with deoxydizing agents (4) it has to be not gasious (5) the slag contacting ith it has to have less oxydising ability.

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The effect of hydrogen on the flakeformation was summerized follows:
(1) The degree of flakeformation was generally parallel to the total hydrogen of steel, that is, if the total hydrogen content increase, flakes appeared more violently and if the content decrease, the appearance of flakes weakened and then vanished. As the more quantitative representation, if the total hydrogen content be more than 6×10_-4% H₂, flakes appeared surely, but less than 4×10_-4% H₂, flakes vanished. Then it was confirmed that steel has a critical total hydrogen content to the flakeformation, but this critical value has a wide range of about 2×10_-4% H₂.
(2) The degree of flakeformation telated more closely to the hydrogen content evolved from the steel in the room temperature than the total hydrogen content did not relate at all to the hydrogen content evolved only in the high temperature. That is, if the hydrogen content evolved in the room temperature be less than the critical value, flakes would not appear even if this steel has a high total hydrogen content, but if more than critical value, flakes would appear even if the steel has a less total content than the former. In this experiments the critical value was about 2cc H₂/100g Fe, but also had a narrow breadth.
(3) From the results of this and the former (2nd Report) expriments, it was confirmed that the supersaturated hydrogen in steel would be playing a substantial role in the frakeformation.

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The author investigated the effect of gases (CO, CO2 N2, H2 ctc) on cast iron. The results obtained are as follows:
(1) Keeping at 900°C, N2 hinders graphitization, but quickens it at the cooling stage.
(2) The previous history and treatment affect graphitization characteristic periodically.
(3) Gases which quicken the solution of graphite hinder its precipitation, and those hinder The solution quicken its precipitation.

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Low carbon Mn steel containing 13-15% Mn of austenite-state changes to martensite-state with cold working. This cold-rolled steel revert again to austenite-state containing higher Mn content with tempering. W. Jellinghaus has already reported that such alloys are suitable to make thin magnet plates. We investigated the changes of X ray-and Micro-structures, effects of carbon and reduction degree, effect of tempering temperature and anisotropy in the magnetic properties.

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