In recent literatures, it has been presumed from the electric-resistance measurement, the magnetic analysis and the hardness measurement that in the alloy of the composition of atomic ratio 1:1 in Fe-Cr system, a superlattice would be formed, if the alloy is quenched from 1000° and annealed at 500° for a week followed by furnace-cooling.
To ascertain this presumption an X-ray examination was performed. The specimen, which was heat-treated as described above, was X-rayed, Mn-K radiation being used to make the superlattice lines distinct.
The diffraction pattern obtained shows no superlattice lines but only fundamental, where as it is predicted that the superlattice lines would be sufficiently strong to be detectable on the assumption of the superlattice of CsCl type. Therefore, it is concluded that the superlattice of a long range order is not present.

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Several single crystals near the composition MgCd₃ were prepared in vacuum by the Tammann-Bridgman method. Using these single crystals, we measured the thermal expansion through the order-disorder transformation in the two crystallographic directions, namely, in the directions parallel and perpendicular to the principal hexagonal axis. It was found for MgCd₃, containing 74,5 atomic%Cd, that the transformation from an ordered state to a random state was accompanied by a remarkable anisotropy in the thermal expansion, viz, an expansion of about 4.3% was found in the direction parallel to c-axis, while a contraction of about 1.5% was found in the direction perpendicular to c-axis. The net change of volume associated with the disordering process was thus found to be an expansion of approximately 1.3%. These data were compared with our previous results obtained by the dilatometric study of the polycrystalline specimens.

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Studies on the superlattices of ternary alloys have recently been developed, but only a few experimental results by X-ray have been reported. The ternary system of iron-aluminum-silicon, which contains the industrially important, ferromagnetic alloy “Sendust” and has two superlattices of the same type on the iron-aluminum and iron-silicon sides, offers various interesting problems in connection with the superlattice theory.
The present work was undertaken in this ternary system to confirm by X-ray a composition-range in which the superlattice of the 3:1 type can exist, because no work concerning it had yet been reported. The result showed that all ferromagnetic singularities were found in this composition-range.

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In the previous report,the authors interpreted the problem of break-up of Laue spots elongated by tensile deformation. In this report, similar phenomena provoked by bending were studied. Materials examined were Zn and Al single crystals. The originations of the phenomena were investigated to be as follows :
(1) The break-up of Laue spots is radically related to some secondary structure (such as so-called sub-structure) of crystal grain and its mechanism is adequately interpreted by the idea of micro-recrystallization (temporarily called by the authors)
(2) Being related to the main divisional planes of this sub-structure, one of them is always nearly perpendicular to the plane and direction of initial slips.

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For the Solid Diffusion NH₄Cl is generally used with the metal or alloy powder. But there has been no report on the mechanism of accelerating action of NH₄Cl upon the solid diffusion. Using the Fe-Al alloy powder, the author diffused Al into steels and many experiments were carried out to clear the mechanism of accelerating action of NH₄Cl.
In a closed tube, Al diffused even into the specimens which do not touch with alloy powder about same order as into the specimens which were embedded in powder. In vacuum, Al also diffused into the specimens which were embedded in powder same as in the closed tube. In all cases the effective amount of NH₄Cl is about 0.1∼0.2% and larger amount of NH₄Cl does not increase the diffusion of Al.
Using the thermo-balance, the weight change of alloy powder in heating was measured. When no NH₄Cl was added, weight change was very small, but when NH₄Cl was added, weight suddenly increased about from 240°. This phenomena indicated that the alloy powder was activated by the addition of NH₄Cl. The differential thermal analysis was also carried out. In this case, when no NH₄Cl was added there was no heat evolution, but when NH₄Cl was added, large heat evolution occurred about from 220°. In this heat evolution the activated heat would have been involved.
From above results author thought that NH₄Cl would be adsorbed activatedly on the alloy powder at lower temperature.

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In the previous report,the author showed that the NH₄Cl would be adsorbed activatedly on the alloy powder. Now in the present report, the author ascertained directly this point. Using a silica spring balance, the amount of absorbed NH₄Cl on the alloy powder was measured in the vacuum . The results showed the absorbed amount was about 0.2% which is in agreement with the case in the previous report as the effective amount of NH₄Cl.
From the experimental results the author thought the mechanism of accelerating action of NH₄Cl as follows:
(1) NH₄Cl was absorbed activatedly on the alloy powder at lower temperature and disadsorbed as AlCl₃ gas at higher temperature.
(2) AlCl₃ gas was dissociated as follows: \[2AlCl₃=2Al(diffused into steels)+3Cl₂\]
and Al diffused into steels and then Cl₂ gas reacted with alloy powder as follows: \[2Al(in alloy powder)+2Cl₂=2AlCl₃\]
thus AlCl₃ gas was formed repeatedly.
(3) H₂ gas which was created by the dissociation of NH₄Cl was also useful in diffusion.
(4) The reason why NH₄Cl is generally used in the solid diffusion will be explained by the fact that NH₄Cl is absorbed activatedly on mamy kinds of metals and alloy powder.

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Please see pdf. Wrong:andlb eaching Right:and bleaching

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Please see pdf. Wrong:10%Al₂(eO₄)₃, ZnCll₂ Right:10%Al₂(SO₄)₃, ZnCl₂

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Please see pdf. Wrong:Ha₂SO Right:Na₂SO

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The present investigation has been carried out to explain the mechanism of blue-brittleness in steels. In the 3rd∼6th reports under this title, it has been shown that the blue-brittleness would not occur in steels free from the nitrogen and that the more the nitrogen content in steels is the more clearly the blue brittleness appears.
In present investigation the follwoing experiments were carried out.
(A) The effect of the annealing in nitrogen or in hydrogen atmosphere was determined by the tensile test at 0∼350° on the specimens shown in Table 1 and the results of these were plotted in Fig. 1∼5.
(B) The effect of cold work on the blue-brittleness was examined on the specimens shown in Table 2, that is tempered for 1 hour at 180° after cold work at room temperature ; the tensile values of these are plotted in Fig. 6∼8.
(C) The effect of different testing speed was determined on the specimens shown in Table 3 and the tensile values of these are plotted in Fig. 9,10.
(D) The change of specific gravity on the specimens tempered for 1 hour at 0∼350° after cold work at room temperature was measured as shown in Table 4.
(E) The figure of stress by Fry’s method were examined on the specimens that had used for the tensile test at each testing temperature. From those experiments the following results were obtained.
(F) In accordance with either the increase or decrease of nitrogen content in steels by heating it in nitrogen or in hydrogen atmosphere, the degree of blue brittleness varied.
(G) The blue-brittleness decreased on the specimens in which some parts of nitrogen had been precipitated by cold working and tempering.
(H) The temperature range of blue brittleness moved to a higher temperature range with the increase of testing speed.
(I) There is a clear correlation between the blue brittleness and Fry’s figure of stress.
From the present and former investigations authors concluded the mechanism of blue brittleness as follow :
The blue brittleness in steel is due to the precipitation of nitride or carbide from α-iron by the existence of working stress : and the brittleness by nitrogen appears much more exactly in lower temperature range than that by carbon.

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The present investigation has been carried out to ascertain the effect of silicon and oxygen on the blue brittleness in steels.
In the 3rd and the 4th reports under this title it has been shown that the blue brittleness would not occur in steels free from the nitrogen and that the more nitrogen content in steels is the more clearly the blue brittleness appears.
But, on the other hand, the blue brittleness by carbon would likely to appear more than by nitrogen, as the nitrogen in steel diminished at the upper temperature range.
To ascertain the effect of silicon, the short time tensile properties at the temperature range of 0∼320° for steels were determined as shown in Table 1∼2.
All specimens employed for this investigation were air cooled from 950°, and then slowly cooled after being tempered for 3 hours at 550°. The tensile value of each steel is plotted in Figs. 1∼14, and the increased percentage of tensile strength and the decreased percentage of elongation or reduction of area at blue brittleness range are plotted in Fig. 7, and the effect of silicon on the tensile strength (σ_B), elongation (δ), and reduction of area (φ) at room temperature are shown in Fig. 15.
To ascertain the effect of oxygen, the short time tensile properties of steels were studied, as shown in Table 3, the result of which are plotted in Figs. 16∼19, and in Fig. 20 is shown the diagram of percentage of blue brittleness versus oxygen percentage.
These figures show that the blue brittleness decreases with the increase of silicon content, and by the addition of oxygen in steel the blue brittleness increases a little in the property of elongation.

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When the outside layer of molten cast iron solidifies grey, and the other parts white, we call this phenomenon “Inverse Chill”. As it is controlled by three factors, namely, chemical components, cooling rate, and oxygen content, it may be analyzed by investigating it systematically.The inverse chill occurs because of the segregation of oxygen which has chilling tendency, and of the fact that cast iron has two eutectic C and C′ on the Fe-C diagram. When molten ingot is cooled to C′, the surface part solidifies grey,and the dissolved oxygen is driven into inner part. And, when the oxygen content of inner part is too high to solidify at C′, the melt must be supercooled to C at which it solidifies white. As the molten cast iron can be considered as a concentrated carbon solution of iron, there may be a special connection among Fe-O-C,and this connection will disturb carbon to crystalize as graphite. Therfore, 0.01 pct. oxygen which is equivalent to the difference of carbon between E and E′ (=0.0075 pct. ) may be the theoretical value necessary for chilling iron. So, the oxygen content which causes the melt to solidify in inverse chilled state is rather in a considerable amount.Considering that inverse chill is brought about by oxygen, we can avoid it by keeping off the oxygen while melting, viz, evading the strong oxidizing atmosphere in the melting furnace, or not using such slag with much iron oxide or high besicity.
The feature of inverse chill is to have a figure of a concentric circle on the cross-section of ingot, and differs essentially from mottled iron. Mottled iron occurs when iron is on the intermediate state of grey and white, being affected by the alloying elements or cooling rate.

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In connection with the metallic selenium converted from the vitreous state by reheating at various temperatures,the examination was carried out by utilizing X-rays,as well by taking the microscopic structures and the differential thermal curves. The results thus obtained are summarized as follows:
1. As can be seen in Table 2, the selenium metallized by reheating at a temperature 80°∼200°, was found to contain besides the hexagonal one an unknown variety, which had not been detected up to the present time. This variety shows the same crystal structure as the monoclinic selenium deposited at 20∼60° from CS₂ solution of the vitreous selenium, as may be seen in Table 3, which it has hitherto been considered that is cannot be produced by the metallization from the vitreous state.
2. The quantity of the monoclinic selenium co-existing with the hexagonal one was found to be much greater in the metallized specimens heated at the temperature nearest to the melting point than in those metallized at a lower temperature. It was also conceivable from some results of the thermal analysis reproduced in Fig. 2, the transition from the hexagonal selenium into the monoclinic one near the melting point might occur, though not so distinctly.
3. The specimens of the vitreous and red amorphous selenium both tend to crystallize imperfectly at the room temperature after 2 or 3 weeks. Because in the diffraction patterns of X-rays taken with these specimens, (10\={1}0) line corresponding to the hexagonal crystal was only perceptible, accompanied by a very faint line corresponding to the monoclinic one specially in the case of the vitreous selenium, and the other lines reflected by these two kinds of crystals were hardly detectable. Furthermore, it must be postscribed that the aforesaid (10\={1}0) line reflected by the hexagonal forms was observed to be strengthened by heating at a temperature 50° for 48 hours, while the line coming to appear from the monoclinic one remain unaltered. This shows that the metallization of the vitreous selenium at the lower temperature is mainly due to the transformation into the hexagonal selenium and not into the monoclinic one.
4. It was found by the microscopic examination that the nuclei grew in the course of the metallization of seleniun to a set of textures, each radiating out from a nucleus into the vitreous region as shown in Photos. 1, 2, 3 and 4. By the furtherance of the procedure of heating, this texture was observed to be broken down minutely as may be seen in Photos. 5, 6 and 7, and then augmentation of each grain took place, the more remarkably the more the temperature was high, by the recrystallization phenomenon as shown in Photo. 8.

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Separations of boron and magnesium respectively from iron were carried out by a simple procedure with a cation exchange resin “Diaion K”.
Boric acid in an acidic solution of the sample passed through the resin, while iron or other cations were all adsorbed by the resin. From the solution which passed through the resin, boron was determined titrimetrically or colorimetriclly.
Magnesium was adsorbed quantitatively with the resin even in the presence of tartaric acid, on the other hand iron passed through the resin, if 20 cc of 20% tartaric acid solution was added against 1 g of iron and the solution was adjusted to 200 cc and at pH 3. Then, magnesium was eleuted with ammonium chloride and determined gravimetrically as phosphate after separation of manganese and calcium.

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