Using a new vertical apparatus devised by the authors, the magnetostriction of Ni and 9 Ni-Cu alloys has been measured up to 1600 Oersteds in a longitudinal magnetic fields at 0°, −95° and −195°. Under the same condition as the magnetostriction measurement, the intensity of magnetization of the same specimens has been also measured. In these alloys, the magnetostriction curve is almost similar to each other, or to that of Ni. The saturation value of magnetosrtiction of Ni decreases numerically with the increase of Cu content and finally reaches a non-magnetic state. The above consideration is also adapted to the magnetization of Ni-Cu alloys. Next we have obtained the saturation values of magnetostriction λ₀ and magnetization I₀ of Ni-Cu alloys at 0°K by extrapolation and found the following formula. 12.3 λ_0 ·10^6=80-I_0 Finally the density of Ni-Cu alloys has been measured, then we calculated the numbers of Bohr magnetons per atom n₀ and found the following formula. λ_0 ·10^6=7-71 n_0

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In the heterogeneous materials such as carbon steel the grain size of the materials had an influence upon the dispersion of hardness values. Especially, in Vickers hardness values which were obtained by small load tests, the distributions of hardness values revealed particular types according to the grain sizes and loads. In this paper, we studied the problem of Shore hardness values for various carbon steels and discussed its comparison with the results of Vickers hardness tests. The relation between the roughness of the surface to be tested and the dispersion of Shore hardness values has been studied by many investigators, but little research has been made in the metallographic field. The results obtained were as follows: (1) The distributions of Shore hardness values were normal. (2) In general, the dispersion of Shore hardness values were greater in the materials having coarse grains than in fine grained materials. But in homogeneous materials such as pure iron and eutectoid steel, it was noted that no detectable differences existed between the dispersions of hardness values obtained with different grain sizes. (3) The standard deviations of Shore hardness values multiplied with the increase of the hardness values, but in pure iron and eutectoid steel the deviations were less. (4) The coefficients of variation of Shore hardness values were nearly constant regardless of the hardness values.

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The influence of additions of 30 and 40 percent of nickel on thermal expansion in the range from 10° to 50°, rigidity modulus at 20° and its temperature coefficient in the range from 20° to 50°, of alloys of cobalt, iron and chromium has been determined. The relations between those properties of nickel-added alloys and the concentrations are qualitatively almost similar to those in the cases of the ternary alloys of cobalt, iron and chromium and of the alloys added with 10 and 20 percent of nickel; that is, there are two groups of alloys, one of which has a positive temperature coefficient of rigidity modulus and the other a negative, a zero coefficient boundary existing between them. The addition of nickel affects the coefficient of thermal expansion and the temperature coefficient of rigidity modulus of the ternary alloys, as if cobalt can be substituted by nickel; that is, the compositions, at which the thermal expansion coefficient shows the minimum value and the temperature coefficient of the modulus the largest positive, shift to the side of low cobalt content almost linearly with the addition of nickel and reach those in the binary alloy of iron and nickel. Further, if the quantity of nickel is increased, the concentration range having positive coefficients of the modulus becomes wider, and the slope of the latter to the concentration smaller. When the quantity of addition of nickel is 30 percent, the smallest value of the thermal expansion coefficient is 1.87×10⁻⁶ obtained with the alloy containing 21 percent of cobalt, 73 percent of iron and 6 percent of chromium, and when 40 percent of nickel is added, 0.54×10⁻⁶ obtained with the alloy containing 11 percent of cobalt, 87 percent of iron and 2 percent of chromium. In the case of an addition of 30 percent of nickel, the positive largest value of the temperature coefficient of rigidity modulus are +76.4×10⁻⁵ obtained with the alloy containing 21 percent of cobalt, 73 percent of iron and 6 percent of chromium and in the case of 40 percent of nickel +81.0×10⁻⁵ obtained with the alloy containing 13 percent of cobalt, 85 percent of iron and 2 percent of chromium. The largest and the smallest values of rigidity modulus in the case of an addition of 30 percent of nickel are 7.84×10⁵ kg/cm² in the alloy of 60 percent of cobalt, 20 percent of iron and 20 percent of chromium and 4.55×10⁵ kg/cm² in the alloy 37 percent of cobalt, 60 percent of iron and 3 percent of chromium, respectively, and in the case of 40 percent of nickel, they are 8.96×10⁵ kg/cm² in the alloy containing 0 percent of cobalt, 96 percent of iron and 4 percent of chromimum and 4.69×10⁵ kg/cm² in the alloy containing 25 percent of cobalt, 75 percent of iron and 0 percent of chromium, respectively.

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The specific heat of the 12 alloys consisting of nickel and less than 49.32 percent of chromium has been measured at high temperatures in annealed, quenched and baked states by inverse rate curve method. In the case of the alloys containing more than 9.05 percent of chromium, the specific heat-temperature curves in an annealed state showed an anomalous maximum portion extending over the temperature range about 450° to 750°, the maximum points of which changed from about 510° of the alloy containing 9.05 percent of chromium to 560° of the alloys containing 24.43 or 29.14 percent of chromium; the anomaly being greatest with the alloys of the latter concentrations. However, when the alloys were baked at 400° for 240 hours, the anomaly became generally very much larger and especially so, in the alloy containing 24.43 percent of chromium; the anomaly was observed even in the alloy containing only 3.44 percent of chromium. When the alloy containing 21.75 percent of chromium was quenched from 800°, the specific heat curve showed a minimum (heat evolution) at about 480° and then a small maximum at a higher temperature. Thus, it has been concluded that the high temperature anomaly of the alloys of nickel and chromium may be caused by the existence of a superlattice Ni₃Cr in a short range.

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Induction surface hardening method can increase the fatigue strength of force-fitted parts and notched parts of machine elements. In order to clarify the mechanism causing such increase, the authors experimented to confirm the difference results of between the induction through-hardening, flame through hardening andordinary through hardening. From the results of rotary bending fatigue tests we gathered the following facts: (1) The fatigue limits of test piece by hardened the three one another method are very different from especially with notched specimens; e.g., as the test results shown in the following table.
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(2) Two reasons are considered as the mechanism causing such increase of fatigue limits by induction or flame-hardening; the one is the toughnesss of the material itself by rapid heating, the other is the residual compressive stress at the surface of the specimen.

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Following the 1st report, the hardness-temperature relation in tempering and tensile properties for various structures of austempered Ni-Cr steel and Ni-Cr-Mo steel at the intermediate region were measured and the following results were obtained: (1) In tempering austempered specimens at the intermediate region, the initial hardness, though it was lower than that of oil-hardened specimens, was practically preserved below the same temperature as used in austempering, and a little hardening occured at about 350° owing to the decomposition of retained austenite (chiefly γ′) (2) The tensile properties of the specimens fully austempered at the intermediate region were inferior to there of the specimens gained by oil-hardening and tempering, mainly due to their coarse structures of α and θ.

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Study was made of the action of boron in relation to the hardenability of 0.4% carbon steel. On specimens with and without boron, determination of isothermal transformation diagram, austenite grain size and Jominy’s hardenability curve were made. Also the continuous cooling diagram of boron treated steel was determined using Jominy’s and quench method. In this diagram, the intermediate structures were found and the mechanism of their formation was discussed.

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The specific heat of 12 alloys consisting of copper and less than 14.59 percent of aluminium has been measured at high temperatures in annealed and baked states by inverse rate curve method. In the case of the α-phase alloys containing more than 3.98 percent of aluminium, the specific heat-temperature curve in an annealed state showed a low peak at the temperatures about 340° to 300°; the temperature became lower with an increase of aluminium content and the anomaly was greatest with the alloys containing 8.05 or 9.14 percent of aluminium. The anomaly was also observed with alloys in the mixture range; in the specific heat curve of these alloys there was another maximum at about 400°, the cause of which could not be explained. When the alloys were baked at 210° for 230 hours, the anomaly became very large, and the temperature of the maximum was almost constant (about 305°). Thus, it has been concluded that the high temperature anomaly of the α-phase alloys of copper and aluminium may be caused by the existence of the short range ordered superlattice Cu₃Al.

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Al-Cu (4%) alloy was melted, poured in to moulds and then made into ingots, being (1) cooled from the bottom, (2) cooled from the two side of a rectangular mould and (3) cooled from the circumfer ential surface of a cyrindrical moulds (Fig. 1, 2, 3,). Other ingots of the same alloy were obtained cast in a vertical, a tilting and a Züblin moulds. With these ingots the author studied the inverse segregation phenomena in the same method as has been used in the previous experiment. The results obtained are shown in the schematic diagram Fig. 9. In the diagram we see the curve consisting of two portion AB and CD, respectively explained by the super cooling theory (AB) and contraction theory (CD).

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The reddish-brown colourings of the prints in both Mg-Si alloys and Mg-P alloys were confirmed to be caused by the silane gas (SiH₄) evolved out of Mg₂Si and H₂SO₄ in the former, and by the phosphine gas (PH₃) evolved out of Mg₃P₂ and H₂SO₄ in the latter. The colourings of these prints were easily reduced by the Farmers’s reducer. Both the prints of Mg-C alloys and Mg-S alloys showed blackish-blown colourings. The courings of the former was confirmed to be caused by the hydrocarbon gas (C₂H₂) evolved out of magnesium carbide (Mg_mC_n) and H₂SO₄, and that of the latter was due to hydrogen-sulphide gas (H₂O) evolved out of MgS and H₂SO₄. The colouring of these prints were hardly reduced by the reducer.
The more the amount of silicon or phospher contained in the magnesium-treated iron was, the heavier the reddish-brown colourings of the prints became. The colourings of these prints were easily reduced by the reducer. The black colourings of the prints at the segregated part of the spheroidal graphite at the upper portion of the specimen was hardly reduced by the reducer. The existence of magnesium-carbide, magnesium-silicide, magnesium-phosphide and magnesium-sulphide in the magnesium-treated iron could be conjectured from the above experimental results, while these compounds may be adequately explained as complex carbides containing magnesium rather than as pure compounds such as Mg_mC_n, Mg₂Si or Mg₃P₂. The behaviour of these magnesium compounds in the iron looks similar to that of cementite: by annealing of the iron, the colouring of the prints becomes lighter because of the decomposition of the magnesium compound, and by heating the iron until it remelts, the print colours again because of the formation of the magnesium compounds. Generally, the small particles of the spheroidal graphite are separated early in the magnesium-treated melt, and these ones continuously grow in size, while the melt is supercooled. In such a cristallization on process magnesium plays an important role for the spheroidizing of graphite. The irregular form the graphite resulting from the subsequent heating of the solid iron treated with magnesium in the melt shows that these magnesium compounds have not their effect on the spheroidizing of graphite, but decompose of annealing, magnesium being still contained in the iron.

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Study has been made on the effect of aluminium on ditermination of nitrogen in steel. The results are summarized as follows. In the case of determining nitrogen in steel containing much alminium (>0.3%Al) by applying centrifuge-separation-photmetric method without alkali distillation, lower values have always been found than that obtained by applying alkali distillation method. This is not due to the effect of aluminium ions on ammonia-nessler color reaction, but to aluminium nitride formed from nitrogen and aluminium in steel, because aluminium nitride is easily dissolved in alkali solutions, but not so in acids. All nitrogen in common aluminium-killed steel (containing <0.2%Al), however, has been completely determined by applying centrifuge-separation-photometric method. In the case of applying steam-distlling-photometric or titric method, in spite of short time distillation, nitrogen in steel containing much aluminium has been completely determined.

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It is generally known that the estimation of Al is carried out chiefly in gravimetric way. There is no appropriate process to estimate Al in volumetric way except by the bromometric titration of Al oxine. The author found a simple and interesting process by means of neutralization. The process proposed by the author consists in precipitating basic Al carbonate from NaOH solution by blowing CO₂ into the solution. The precipitate obtained is dissolved in a difinite amount of H₃PO₄ of known strength (ca. 0.6N) forming soluble aluminium hydrophosphate Al(H₂PO₄)₃. The phosphoric acid containing Al(H₂PO₄)₃. The phosphoric acid containing Al (H₂PO₄)₃ is then titrated with standard NaOH solution (ca. 0.2N) with methyl orange as indicator. The NaOH solution, after neutralizing the primary dissociation of phosphoric acid, H₃PO₄+NaOH=NaH₂PO₄+H₂O, acts upon Al(H₂PO₄)₃ giving white precipitate of AlPO₄, thus Al(H₂PO₄)₃+2NaOH=AlPO₄+2NaH₂PO₄+2H₂O. The colour of methyl orange turns yellow at the completion of the above reaction. The water suspended with AlPO₄ behaves feebly acidic due to the hydrolysis (ca. pH 4.6∼4.8), but it does no harm during the titration with methyl orange indicator which changes its colour at about pH 4.4. As it is obvious from the above reaction, the excess acid which does not combine with Al to form AlPO₄ can be separately estimated with NaOH at the conclusion of the titration. Strong acids, such as HCl, HNO₃ and H₂SO₄, can not be used for this purpose, as the aluminium salt of corresponding acid behaves acidic toward methyl orange due to its prominent hydrolysis. It is also impossilbe to use weak acid, such as acetic acid: there is no means for titrating the acid separately in the presence of its Al salt. The author shows some examples in estimating Al in Al-bronze, Mg-alloy, and nitrized steel by means of H₃PO₄-NaOH titration.

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The influences of carburizing methods on the graphitization-rate of white irons and on the properties of the annealed irons have been studied. White irons containing about 2.6% C and 1.0% Si were prepared using various kinds of row iron made from steel scraps previously carburized with electrode carbon, charcoal, coke, coke plus calcium carbide, or with coke plus lime. The results thus obtained are as follows: (1) Carburizing efficiency was greatest with electrode carbon, followed by coke and charcoal, and was smallest in coke plus calcium carbide. (2) Malleable irons carburized with coke plus calcium carbide had high ductility as well as high strength after annealing. (3) The iron prepared with charcoal required the least time for the first graphitization and the one prepared with cock plus calcium carbide required the most. (4) In the irons cast with coke, coke plus calcium carbide and coke plus lime, considerable amounts of martensite and austenite were found in the structures during the heating. These white irons showed expansion, which was followed by contraction at 270∼450° due to the decompostion of austenite and martensite respectively. (5) Abnormal structures found in white irons made from various kinds of raw iron using coke, coke plus calcium carbide, or coke plus lime, were found to be mainly caused by the absorption of nitrogen into molten iron during the carburization of the steel scrap.

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The grain refinement of aluminium alloy containing Cu 2.92% and Si 1.17% was mainly investigated by addition of NaF·BF₃ or KF·TiF₄ combined with salts. Results obtained are as follows: (1) The addition of a small amount of KF·TiF₄ up to 0.02% gives scarecely any remarkable effect upon the grain refinement of castings. It is necessary to use a quantity of salts greater 0.02% of in order to obtain of NaF·BF₃ finer grain size. (2) By the addition of more than 0.6%, the grain size of castings becomes very fine, especially when it is added together with a small amount of KF·TiF₄ (0.007∼0.02%), the purpose can be achieved completely. Thus it is thought that effect was given by the simultaneous addition of B and Ti, moreover this effect was observed in the changing of the specific gravity of castings.

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This investigation was carried out in order to ascertain the effect of cholorination upon the purification of metal.
(1) The course of purification by chlorination in a lager scale furnace was similar to one in a small scale furnace, but the consumption of chlorin decreased with the incrase of thesurface. (2) The purification by chlorination was carried out by physical and chemical action, above all it is due to the latter to achieve the purpose of purification in shorter hourse. (3) The change of the specific gravity or α in the course of chlorination was different according as the gas content of th emetal. (4) It is always required to stand the metal for some hourse after chlorination and the relation between this time, the temperature the size of the gas particles dissolved in the molten metal and the depth of metal was introduced theoretically.

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