The author studied the separation of Fe, Al, etc. from the Ni, Co and Mn in the solution which had been extracted from Ni-Cr bearing iron are with a dilute sulphuric acid. The separation process was conducted under high pressure, and the chemical reactions and its preparation were described

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One of the authors informed in the former report of the theoretical assumption of the slag composition necessary for the low-phosphor pig manufacture from the ordinary pig iron. In the present report, the authors measured the melting temperature of the FeO-SiO2-CaO slag(containing some quantity of Al2O3), obtaining the range of slag composition suitable for refining the low-phosphor pig.

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Nous avons fait une petite étude en vue d'éclaircir des facteurs sous la dépendance desquels se trouve le grain austénitique de l'acier. O'est, en général, la méthode par cémentation, qui s'est utilise pour mettre en évidence le grain austé nitique. Cependant, dans lee cas ou it est impossible de cémenter d'échantillon, on a recours à la méthode par oxydation ou par trempe martensitique.
Des échantillons qui sont prélevés du bain au cours de l'opération du four électrique, avant de la calmer avec l'aluminium, montrent souvent une structure mixte formée d'ilots de trèe gros grains dans un fond à grain généralement fin, tandis qu'est anormale la structure des échantillons du bain de la durée d'oxydation d'op é ration. I1 serble que la grossenr du grain d'aust é nite est la même quelle que soit la durée de séjour en poche ou la place de prélévement du lingot. D'une manière générale, la grosseur du grain d'austénite d'un acier semble indépendante du degré de corroyage à chaud ou de l'é crouissage. Mais dans les échantillons, montrant une structure extraordinairement mixte, dont les coëfficien's d'écrouissage sont supérieurs à environ 90%, les gros graine sont déformé s et allongés dans la directions de traction. Par addition à la coulee d'une quantité critique en aluminium (jusqu'a environ 0.030.1%), en titane (environ 0.02%), en vanadium (environ 0 2%), en molybdene (environ 0.6%), le grain austénitique devient de plus en plus fin. Le grain d'austénite formé par solidification est extraordinairement plus gros que le grain formé par transformation et sa grosseur est moins dépendante de la quantité d'aluminium. pour d é soxydation. I1 est probable que lee suspensions d'alumine jouent pintôt le rôle de barrière que celui de germes, pour l'aptitude an grossissement du grain d'aust é nite.

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In the present investigation the coefficient of diffusion of silicon and phosphorus in solid iron were measured and the effects of carbon on this coefficient studied.
The results obtained were summarized as follows;
1) The coefficient of diffusion of silicon is 7×10^-5 sq. cm. per day at 1000°C; 15×10^-5 at 1050°CC;35×10^-5 at 1100°C; and 56×10^-5 at 1050°C.
2) The coefficient of diffusion of phosphorus is 9×10^-5 sq. cm. per day at 1050°C; 21×10^-5 at 1100°C; 33×10^-5 at 1150°C; and 70×10^-5 at 1200°C.
3) Both coefficients of diffusion of silicon and phosphorus increase appreciably when diffused simultaneously with carbon in the same direction, while they decrease markedly in the opposite, direction.
4) The heat of diffusion which was determined graphically from the variation of coefficient of diffusion with temperature is 48, 200 cal. per gram atom for silicon and 52, 300 for phosphorus. These value are in accordance with the Dushman-Langmuir equation.
5) The diffusion equation may be written:
Dsi-γFe=18, 000.e-48, 200/RT
Dr→γFe=42, 000.e-52, 300/RT
for silicon and phosphorus, respectively, in which D is the diffusion coefficient, in sq. cm. per day, e the base of the natural logarithms, R the gas constant and T the absolute temperature.

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Method of strong etching has been developed in order to investigate the homogeneity of steel.
Nippon-Gakuzyutu-Sinkôkai (Japan Society for Scientific Promotion) and Heiki-Kôgyôkai (Muuition Industries Association) have rently determined the standard method of the. strong etching, of which the research is rather phenomenological. On reexamining it, the following results were revealed.
When an electrolytic etching is adopted as a method, it is possible to obtain the same result as in the heretofore method with in a short time at ordinary temperature. Purity of acid, heat treatment, quality of the material tested, forging ratio, etc. are counted among factors influencing the result of etching. Pittings formed after etching are due to dissolution of sulphides and some oxides liable to be attacked by acid.
Sil cates have rather little effect. Sulphides everi if in small size, conglomerate into large pittings. The first means to improve the result of strong etching is nothing but desulphidation.

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Being judged from literatures and the author's experience, the elongation e is represented by the experimental formula ε=cin in the first stage of creep which continues at least 1000 hrs. at 500°C or below, and in the second stage the velocity of creep is approxithately constant. So the velocity at the end of the first stage, approximately equal to the velocity in the second stage, is ca culated from the foimu a v'=nε'/t', wbere t' is the time interval of the first stage and ε' the total elongation of creep of the first stage; and ε' is obtained by the logε-ogt straight line ex-trapolated through tl e first stage.
It was pointed out that the creep strength is more precisely inferred from the velocity v' calcu-lated as above than from the mean velocity of the short duration v, for v' varies considerably even if v is constant, according to the variation of n with the material, the testing temperature or the stress applied. In applying the present discussion, the author investigated the effect of various heat treatments on. Cr-Mo steel by the extrapolating method abovementioned, showing that the nor-malized and tempered specimen has greater creep strength than the q.quenched and tempered one.

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