The preparation of single crystals of zinc, bismuth and white tin by sucking from melt was tried with a simple apparatus and procedure. Single crystals 5 mm in diameter and 5∼7 cm in length of bismuth and tin could readily be produced with percentage of success of 40 and 60 percent, respectively, though zinc single crystals were not obtained. Orientations of crystals prepared by this method prefer such directions that the rod axis is inclined by about 80 degrees to the trigonal axis for bismuth and by about 85 degrees to the tetragonal axis for tin. It was found that the suction method had a possibility of general application to the production of metallic single crystals.

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Meaeurment of the average grain size in 7:3 brass specimens heated for various periods of time after cold working gave the following results :
(I) The average grain size D at time t can be expressed as the following eqation for isothermal grain growth from 400° to 700° : D=kt^n\labeleq1The parmeters n and k are functions of the temperature. This result agrees with that which Beck et al obtained pure aluminium.
(2) The grain size increases with time and temperature.It depends further upon the degree cold working before annealing, and the higher the value of draft percentage,the finer the recrystallized grain size.
(3) From equation (\ efeq1) the instantaneous rate of grain growth is given by \fracdDdt=nkt^n-1\labeleq2
or \fracdDdt=nkD^\frac1nD^1-\frac1n\labeleq3Therefore, if log\left(\dfracdDdt\ ight) is plotted vs. logD, a=straight line must be obtained for each temperature. This shows that the rate of grain growth is dependent of the instantaneous grain size alone. The data obtained show that this conclusion is correct. Since n<1, eqation (\ efeq2) shows that \dfracdDdt lecreases with continued annealing, in accordance with experiments.

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Once we observed an unreasonable phenomenon that the coil constant of a solenoid determined ballistically varied with the intensity of current passing through it. It is shown experimentally as well as theoreticlly that this apparent change of the coil constant is entirely due to rather unexpected mutual induction between the solenoid and resistance boxes usually connected in the galvanometer circuit, in spite of the fact that the resistance boxes are usually constructed to be almost non-inductive. This usually neglected source of error is to be carefully taken into consideration in magnetic measurements by means of the ballistic-galvanometer method.

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For the γ→α (or α′) transformation occurring during temperature variation in iron alloys, the following two lattice-relationships are known to be adoptable in some cases : 3 & Kurdjumow-Sachs^(1) &  & (KS) & & : γ(111)\varparallelα’(011),  γ[\bar101]\varparallelα’[\bar10\bar1],
& Nishiyama^(2) & & (N) & & : γ(111)\varparallelα(011),  γ[\bar211]\varparallelα[01\bar1]. Recently, Neerfeld and Mathieu⁽⁴⁾ studied the transformation under tension using 18-8 steels and Fe-30%Ni alloys, and proposed a new relationship : \[(NM):γ[111]\varparallelα[012], γ[01\bar1]\varparallelα[100], γ[\bar211]\varparallelα[02\bar1],\] since they thought that X-ray patterns taken by them could be interpreted with neither KS-nor N-relationship.
In N-relationship, however, the number of transformation shears is twelve (Fig. 2). In care external force is applied, the possibility of the occurrence of these shears is not equal, the transformation taking place predominantly by shears having the greatest shearing force. When the applied force is tensile in the γ[111] direction, as in the case of Neerfeld and Mathieu’s experiment, those prominent shears may be represented by a shear γ(1\bar11), γ[121] (Fig. 3(a), By), by which an alpha crystal is formed having the orientation different from that of the NM-relationship corresponding to this shear by an amount of only 1°02′ about [100] axis of the former, as shown in Fig. 1. Such a small difference of orientation suggests that it must be very difficult to determine which holds better, N-or NM-relationship, by inspecting Neerfeld and Mathieu’s Dabye-Scherrer photographs, which were taken with a specimen of poly-crystals of fibrous structure. Therefore, their conclusion that, NM-relati nship holds better than N in the present case, was too hasty.
The author’s former experiment⁽³⁾, in which a single crystal of stainless invar was transformed by compression, is also insufficient to determine the adoptability of the two relationships.
Neerfeld and Mathieu have stated in addition, that from the theoretical standpoint NM-relationship has the advantage over N-relationship that the atomic movement during the transformation is smaller by the former than by the latter. The advantage, however, may be canceled because the atomic movement by N-relationship becomes nearly equal to that by NM, if the predominance of certain transformation-shears is taken into account as mentioned above.
In short, it may at present be concluded that there is no necessity of the new NM-relationship from the experimental and theoretical standpoint, even in the case of the transformation caused by stress (plastic deformation). Further studies will solve this problem in future.

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Some years ago, the present writer found that the austenitic grain size of heat-treated steel-casting is linearly proportional to degree of super-heating of Ac₁ transformation of steels, and that it is attributed to the promoted dispersion of the nuclear substances in steel due to stress acompanying the transformation. There is, however, some question about the stress in so high temperature as Ac₁ point of steels.
So, in the present papar, the occurrence of the stress in question is theoretically discussed, and checked by the previously reported experimental data. Thus it is found that there exists linear functional relation between the grain size of the heat-treated estel-casting and the logarithmic rate of heating through the Ac₁ transformation. This simple relation shows a fact that the change of grain size is a function of stress accompanying the Ac₁ transformation of steel.

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Under the carburizing conditions as described below, all the phenomenan in this carburizing process were explained from the increased weight and by examining the surface and the section of the specimen with the electron diffraction method and a microscope. The specimen is the uniforming of carbon concentration between the surface layer and the middle part of the section arrives as soon as possible. The carburizing gas is composed of 65% nitrogen and 35% carbon monooxide, so that the surface reaction rate which is later than diffusion rate of carbon determines the carburizing rate. The result is as follows : until the speciemen is saturated with carbon from the start of carburization, the carburizing rate decreases in inverse proportion to the increased carbon concentration. As soon as the specimen is saturated at Acm line, the graphite precipitates and grows quickly on the surface of specimen. The mechanism of the graphite deposition was discussed from the graphitization theories on amorphous carbon and cast iron. In the interior of specimen, Fe₃C phase grows at the grain boundary after saturation of carbon. However, when the carburizing further proceeds, Fe₃C phase disappears gradually with the occurence of graphitization. On the other hand, on the surface of the specimen, after saturation of carbon, carbon is deposited, and the depositing rate becomes larger in consequence of the increased surface area by the diffusion of iron in specimen to the deposited carbon.

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The present investigation has been carried out to ascertain the effect of nitrogen on the blue brittleness in steels by removing it from these steels.
To remove nitrogen, hydrogen or hydrogen with water vapour saturated at room temperatures was used.
The short time tensile properties of steels at temperatures between 0° to 320° are plotted in Fig. 2∼15, and the increased percent of tensile strength and decreased percent of elongation at the blue brittleness temperature range are plotted in Figs. 7 and 8 ; these figures show that the brittleness die out in steels free from nitrogen, but, on the other hand, the brittleness by carbon comes to appear, as the nitrogen in steel diminishes, at the upper temperature range than by nitrogen, and that is markedly recognized in elongation curves.

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Effect of heating upon the properties of the plastically deformed mild steel (C=0.23%, Mn=0.09%, P=0.043%, S=0.029%) has been studied using X-ray back reflection method, measurement of hardness by Vickers hardness tester and of length by Universal Measuring Microscope. The curve of Vickers hardness versus temperature has two peaks, the one at 100∼300°, the other in range 400∼450°. The former may be an effect of “blue shortness.” Present authors inquired into the latter phenomenon closely and concluded that it was simply due to the precipitation of Fe₃C.
After elongation of several per cent, the lattice constant a_η, plane of which is nearly parallel to the surface of the specimen, becomes larger than that of the one which is not plastically deformed (i. e., a₀), and the lattice constant a_45°−η′ plane of which is inclined about 45° to the direction of tension, is smaller than a₀. After heating up to 250∼350°, a_η bscomes smaller then a₀. On the other hand, a_45°−η′ becomes larger, but does not exceed the value of a₀.
By heating up to 400∼450° both a_η and a_45°−η′ tend to approach a value which is smaller than that of a₀ by 0.3%, and this state is maintained up to about 700°.
Moreover, these specimens contract in volume by 0.06% at that temperature.
These facts and also the retardation of softening at these temperatures reveal that the carbon supersaturated in ferrite precipitates in the form of Fe₃C, i. e. precipitation hardening.

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In spite of the fact that the manufacturing of pig iron by means of the cupola type furnace using the steel scraps has been operated from the acient time, the literatures concening it are scarce. In the present study, the author has reexamined the construction of the furnace in order to improve the reduction-smelting and the carbon absorption. The various improvements which the author has introduced are summerized as follows : The hearth adopted was larger than the old type in height between the tuyere and charging door and tuyere ratio. These improvements have remarkably changed the properties of the regenerated pig iron.

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In the present investigation, authors re-examined the effect of some fluxes and Cl₂ gas on removing slags and gases of the complex Al alloys. The results obtained are as follows : Borax is little effective for that purpose. Particularly it is dangerous to use borax only, because it is inferior to another flux in its seperation from molton alloy.
ZnCl₂ which is oridinary used for the same purpose, is more effective than Borax. Its capacity of refining is considerably weak compard with Cl₂ gas. Cl₂ gas is remarkably excellent in refining capacity among all fluxes. After passing it, the molton alloy become finer and finer with the elapse of time for settling. The running quality did not agree with settling times. That is, one peak appeared in the curve of running quality-settling hours.
Removing of gases is accomplished by means of the dispersion of Cl₂ gas to inpurities in molton alloy but it is not ascertained in the present investigation.

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In the mathematical analysis on the carburization and decarburization of Th-W filaments, it must be recongnized that the carburized layer is distinguished from the decarburized and that the carbon content does not vary continuously. This differs from the carburization and decarburization of the common metals such as iron, so that the conventional solution on the Fick’s equation of diffusion is not applicable. Therefore, we obtain the following solution, using the Stefan’s method of the calculation about the formation of ice. \left. rl & \dfrac4ktR^2C_0=s+(1-s) log_e (1-s)
& K=D(C_1-C_2),  S=\dfrac1f \left(1-\dfrac1λ_0\ ight)  for carburization
and & K=D_1C_2,  S=\dfrac1f-\dfrac1λ_0 \left(\dfrac1λ_t-1\ ight)  for decarburization\ ight}\labeleq1Where, C₁ represents the concentration of carbon at the surface (g/cm³), C₂, the concentration of carbon dissolved in the tungsten and not present as W₂C, C₀, the amount of carbon required to convert unit volume of W into W₂C, D and D₁, the diffusion constants of carbon into W₂C and W respectively,R, the radius of Th-W filament, t, the time of carburization and decarburization, S, the ratio of area of carburized sheath and total section for carburization and the ratio of area of decarburized sheath and total section for decarburization, λ₀, the ratio of resistance after and before cecarburization, λ_t,the ratio of resistance after and before decarburizaton and f,the constant related with specific resistance.
Analysing the carburization data by equation (\ efeq1), we get D(C₁−C₂)=7.52×10⁻⁹, 5.36×10⁻⁸ and 2.178×10⁻⁷ cm² g/sec for 1700°, 1850° and 2000°K respectively.
Applying the Vant’ Hoff’s equation on the thermodynamical equilibrium, we obtain Q=32300 cal as an activation energy on the diffusion of carbon into W₂C. Similarly, in the case of the decarburization in hydrogen, we get D₁C₂=1.6×10⁻¹⁰, 3.76×10⁻⁹ and 2.8×10⁻⁸ cm² g/sec for 1650°, 2000° and 2150°K respectively and Q=24430 cal.

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With the object of studying constructional 0.3%C steel and ducole steel having large value of corrosion resistance, a series of corrosion tests by dip method such as dipping in water, MgCl₂, NaCl and K₂SO₄ 1⁄10 mol solutions small amount of which was in atmosphere, was carried out.
The similarity between corrosions in neutral salt solution containing oxygen diffused from the atmosphere was the same.

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A simple method for analysis of Be in Cu-Be alloy with a minute amount of the sample was studied. After Be separation from Cu and others by precipitating with guanidine carbonate, Be was determined colorimetrically with “Aluminon”. In this method most suitable procedure was presented.

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