The influence of the addition of a foreign element on the superlattice formation of the AuCu₃ type, especially the change of transformation temperature, was studied on the basis of the Bragg-Williams theory of superlattice. Calculations were carried out to several simple cases. The results were discussed in connection with the real ternary alloys.

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Young's modulus and its change by magnetization in annealed γ-phase Ni-Co alloys were measured with the method of magnetostrictive vibration. The ΔE-effect in alloys of low cobalt content (0_??_15% Co) is positive up to its saturation, while the effect in alloys of high cobalt content (21_??_59% Co) is negative at low fields, and then becomes positive at higher fields. These i egative ΔE-effects are far more conspicuous than those hitherto known. The saturation valces of the ΔE-effect, positive for all alloys, show two maxima and two minima. The first maximum at 3% Co amounts to about 28%, this being the highest value of the ΔE-effect found at ordinary tenperatues. Yeung's moduli at demagnetized and saturated states changes similarly with composition and both show sharp minima at 3_??_4% Co.

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The phase changes of steels in solid states may be classified into two kinds, the precipitation of ferrite (α) or cementite and the formation of martensite (α'). The mechanism of the one is very differ from other. The detailed interpretation has already been given by one of the present wriers. As regards the martensite, by the process of so called “ Umkloppen ” is generally accepted, although its n echanism has not yet been aufficiently interpreted.
On this paper, we shall consider the mechanism in detail; to make the differencns of nature, clear between two kinds stated above.
The facts hitherto obtained by the experiments on the formation of martensite show that this transformation consists of a great many minuites and impulsive change takis extremely short time. Hence it is concluded that the change occurs by the mechanism, does not need any diffusion of atoms as in the case of the precipitation. On the other hand, in view of the relation betwcen the crystallographic orientation of austenite (γ) and that of the martensite (α); the mechanism of the transformation should be like the mechanical slip in the case of twin-formation. Considering these facts, we support the theory that martensite forms through the process of Umklatypern. and proposes the following assumptions for its mechanism; so as to be possible to explain all the experimental facts.
i) In the Umklrppen at first an atom which activation energy is lowered dues to the defect of the crystal lattice displaces to a new position which is a lattice point of the new phase (α'). And then. this displacement propagates in the crystallographic directions with such a great velocity of elastic vibration, which results a slipping of atomic planes to form one needle of martensite.
ii) The elastic waves are accompanied by the formation of this martensite needle, other needles successively formed around it become a group.
iii) Many of such a group form at random in the specimen.

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電解鐵及び市販熔鐵を原料として種々の状態をつくり, 又一方鋼を調整してこれ等を試料として,滲炭を行ひ,その滲炭深さと滲炭重量とを,銅メッキ法の適用によつて精密に測定した.本研究によつて滲炭深さと滲炭重量とは比例せぬ場合が少くないことが知られた.又,滲炭剤中BaCO₃の配合比の増加は概して滲炭深さよりも滲炭部C濃度の増大に作用することを明らかにした.電着せるゝまの鐡にみるフエライト粒の著しい方向性はA_s變態によつて消失し,滲炭度と滲炭方向との關係として特に認むべきほどの變化を生じなかつた.尚電解せるまゝの鐵は炭層が深くなつても滲炭量が僅少である事實を認め,その理由を考察した.

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The Influence of tungsten and sulphur up to 14% and 0.3% respectively, on the degree of carburization, the grainsize and microstructure of steel have been studied. Tungsten and sulphur retards the carburization. The austenitic grain size of tungsten steel is very fine. The addition of tungsten and sulphur are apt to form abnormal structure and tungsten have tendency to graphitize the cementite.
By utilizing magnetic analysis, the nature of carbides in carburized specimens were studied; in tungsten steel the magnetic change of ferromagnetic carbides take place at about 20° and 400°. The former is due to Fe₃C while the latter is due to the double carbide probably (Fe₃C)₄ WC. Sulphur has no solid solubility to Cementite.

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Charpy impact tests were carried out with respect to four kinds of steels, i.e., low carbon steel, soft steel, chrome-molybdenum steel and chrome-mangmese austenitic steel at the temperature range between 20° and-195°
The notched specimens, having the standard Charpy type, were made either from the part that was welded by means of an electric-are method. using welding rods of the same composition as the material to be welded, or from the unwelded part of the said steel plates; in the former case the position of the long edge of the specimen perpendicular to the welded line. The specimens were finished in the desired form of the complete specimen by means of a grinding machine after a suitable heat treatment of quenching and tempering. Among the four kinds of steels cited above, chromemanganese, steel of austenitic structure showed the largest impact value down to the liquid-air temperature, under both welded and unwelded conditions.
Tensile tests were also performed to the aforesaid steels, with the specimens 6mm in diameter, in the said temperature range.
Brinell hardness was also measured on the part of welding as well as on both sides of that part.

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The relations between the bottom curvature of a notched bars and its fatigue strength has already been investigated experimentally by Mr. Masatoshi Ono and Dr. Kansei Ono for carbon steels and Ni-Cr steels. The present expe:imental research was also done by the same case, but with specimens of a Ni-Cr steel have more shallow V-type groove than that of Messrs. One. The test pieces used for the present experiment had a diameter D of 12mm, a bottom diameterd of 10mm, and the radius of curvature at the bottom of the V-type groove was changed to 7 stages of 0.08mm, 0.12mm, 0.16mm, 0.20mm, 0.30mm, 0.50mm and infinity. The result of the experiment was as follows: The stress concentration factor was raised as d/p was raised from 0 to 30, but it became the constant value of 2.3 even when d/p increased allove CO to 100. The, stress concentration factor of the present experiment was lower than that of Messrs. Ono, but this is deemed due to the difference of the surface finishing of both test pieces. (The surface of the present test piedes was finished lastly by grinding machine.)

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Pure molten Selenium easily endues to glass form by the rapid cooling which crystallises out by reheaitrg. When the reheating temperature is higher than 100°, it evolves great crystallisation heat which often causes self-fusion. The authors have studied the crystallisation of surfused Selenium at various temperature up to 200° and ascertained. The rate or crystallisation at below 100° is proportional to third power of the heating time. The relation between the degree and super cooling; The crystallisation-velocity and the nucleus number were measured as shown in Fig. 8. From these relations, it is concluded that the power of crystallisation gets to maximum value at about 120°.

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The tensile strength and hardness of β-Al bronze increase and elongation decrese when it is quenched and tempered. The tempering effect of this kind is most remarkable when it tempered at 350°. The tensile strength and hardness decrease above 350° in the temperature range. But the elongation increas. The tempering effect increases with the addition of Mn, bnt not over 6%. The mechanical property of β-Al bronze is influenced by three factors, namely the quantity of Al and Mn contents and the tempering temperature, so it is difficult to decribe in brief the effect Mn addition has on the β-Al bronze, however in short the mechanical property of β-Al bronze can be remarkably improved by Mn addition, especially by 5% Mn addition.

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There are many compounds for pigments. in which blue pigment known as Cobalt-Blue is mainly cobalt aluminate produced by the reaction between alumina and cobalt onide at high temperature. We considered this reaction and the resnits obtained as follows.
(I) The compound production at about 1000° is indigo-blue cobalt aluminate (CoO.Al₂O₃), the reaction proceeded by the diffusion. It is clear that this reaction. Janders diffusion formula can be applied.
(2) The elistence of this compound is ascertained through the X-ray analysis, the lattice constant of the spinell type cubic lattice is 8.03A.
(3) In this reaction activation energy of diffusion is 30000 col.

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1. Influeac_??_s of deviation on the supply electric-potential and cycle in the quantitative condensed spark method to the blackness of spectrum lines were studicd. It was found that the enla_??_gement of the electric-potential, the cycle increased the blackness; the mean error by the deviation of the potential was±1.5% and by the cycle was ±2.0% to ΔS in the rarge 48._??_5_??_50.50∞ in Japan, at the present circumstanc_??_s. 2. One Ellipsis of standard samples was studied. It was applied to ΔS of some tow lines in iron-spectrum, which was produced by change of Self-Inductance L.

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