The present experiments were carried out by the qualitative measurements of the temperature dependency of conductivity, and by taking the differential thermal curves, utilizing the specimens metallized from vitreous selenium.In addition, the electrical property of the deposited monoclinic selenium was studied. In summarizing the results, the following conclusions were obtained; (1) In the metallized selenium the reversible thermal change occurred at about 209°. (2) From the considerations of the conductivity-temperature relations, it was found that the allotropic transformation would occur at a temperature which correspounds to the thermal change, that is, one allotropic form which was stable below about 209° had the positive temperature coefficient of conductivity in both cases of heating and cooling, but another form which was stable in a temperature range higher than about 209° showed a tendency of the negative temperature coefficient especially in the case of super-cooling. The former was the hexagonal selenium and the latter (in the super-cooled state) was supposed to be the monoclinic one, considering from the X-ray results previously reported by the author. (3) Examining the deposited monoclinic selenium, it was found that this variety was originally a good conductor, but because of the occluded gas, probably CS2, behaved like an insulator.
The conductivity of the metallic selenium converted from the vitreous state was qualitatively investigated as a function of temperature with parameters of metallizing temperature and its heating period. From the results thus obtained, it was found that there are various different types of the conductivity-temperature curves, and the main difference between them is due to the existence of the monoclinic variety, mixed with the hexagonal selenium. From the microscopic examination, it was confirmed that the specimen, classified by the micro-structure like photo. 1 which appears in the first stage of the metallization of the vitreous selenium, gave the conductivity-temperature curve characterized by the hexagonal selenium; but, if such a structure is broken down minutely into the state like photo. 2 by the furtherance of the heating procedure or with rising temperature, in the majority of cases, the monoclinic variety will be formed by the transformation of the hexagonal selenium even at a lower temperature than the transformation point (about 209°). The cause of such a micro-structural change was supposed to be due to the internal strain which resulted from the metallization of vitreous selenium.
Using a new-designed capillary X-ray tube, characteristic diffraction patterns by divergent radiation were obtained by both transmission and reflection method. Specimens used were single crystal plate of Al about 0.1∼0.5 mm thick, and the radiation was Cu-Kα. Here was studied the analysis of these characteristic patterns relating to the perfectness of crystals in the state of deformation. The summaries are as follows: (1) New designed capillary X-ray tube by the author was set on an optical bench and the electron focussing devices are so excellently equipped that the exposure time was much shortened. (2) In transmission, the diffraction patterns obtained were composed of black and white lines and very alike to those by Kossel, so that they are temporarily called “Pseudo Kossel patterns” here. (3) The precision degree of the measurement of lattice dimensions and the orientations of crystals by pseudo Kossel patterns was much better than those by the routine method. (4) Relating to the perfectness of crystals, the results of the author were a little different to those obtained by means of electron diffraction method by Heidenreich & Schockley.The diffusion or disappearance of pseudo Kossel lines was indefinite, and some of them subsisted up to the state of considerably hard deformation.
The internal friction of pure iron and nikel, subjected to the plastic deformation of various degrees,was measured by means of the resonance of longitudinal oscillation. The maximum strain amplitude was less than 10−6, and the frequencies was about 15 K.C. Types of the plastic deformation employed are tensile, and simple-and repeated torsional. It was found that (1) the internal friction decreased rapidly with the degree of plastic deformation, and (2) it had a peak at some degree of working. The fact (1) appeared at very small degree of working, The fact (2) appeared just befor the fracture for nickel and just after (1) for iron. The former may be of the feromagnetic origin,while the latter may be due to dislocations.
By thermodynamic considerations of a model for breaking, a formula connecting the breaking strength of a crystal with its thermodynamic functions was obtained. In the special case of simple tensile test with internal stress-free polycrystalline specimen at 0°K the formula coincides with Fürth’s one. The formula is successfully applied to such problems as the tensile test on a specimen with internal stress under usual condition, or under hydrostatic pressure, etc., but it fails to evaluate the strength for the compression test, because the numerator and the denominator of the formula tend to zero simultaneously.
In ternary alloys of eutectic type, if the length of Ea is longest and that of Ec is shortest as are shown in Fig. 1, it is considered that the structure of alloys of such composition as are indicated on (i) Ea, (ii) Eb and (iii) Ec ars formed (i) from primarily separated (A), secondarily separated (C), tertiarily separted binary eutectic (B)+(C) and ternary eutectic (A)+(B)+(C), (ii) from primarily separated (B), secondarily separated (C), tertiarily separated binary eutectic (B)+(C) and ternary eutectic (A)+(B)+(C) and (iii) from primarily separated (C), secondarily separated binary eutectic (B)+(C) and ternary eutectic (A)+(B)+(C), respectively.Above consideration was confirmed in Cd-Bi-Sn alloy. In binary alloys the S-side component are the ground mass of binary eutectic or eutectoid structure, in which exist the other side (i.e. P-side) component, if eutectic or eutectoid point S is nearer to P than to K on eutectic or eutectoid line PSK (i.e. PS<SK), and vice versa. In ternary alloys (B) are the ground mass of ternary eutectic structure, in which exist (A) accompanied by (C). Some considerations concerning with the above mentioned structure of eutectic or eutectoid were made.
The ball bearing is constructed of balls, inner race, outer race and retainer (solid or pressed). It isthe most important for the solid retainer to have a high tensile strength and also good anti-wearing properties against the quenched Chromium bearing steels. The author, here, has selected copper based 13 alloys, aluminium based 8 alloys, and 5 ferrous alloys as specimens, and excuted the tension tests of these 26 alloys and wearing tests against bearing steels, using Suzuki’s wearing test machine. The wearing test conditions are as follows: pressure 3, 5, or 7 kg/cm2 in air, velocity 56 cm/sec, and pressure 15 kg/cm2 in transformer oil, velocity ditto. As the results of total worn weight of both bearing steel and specimen in oil, the following materials are recommended to be excellent as the retainer material in the order of superiority: stainless steel (Mark 7), broze (A and B), malleable cast iron (10), free cutting steel (9), phosphor-bronze (I, K, and T), silzin bronze (M), Al-Sn-Cu alloy (3), mild steel (8), and Pb bronze (D). The stainless steel is the best in wearing test, but will be difficult to be used as a retainer, owing to its bad heat-conductivity.
1. Small amount of carbon in iron plate was determined by low pressure combustion method,by which the gases were pumped over the platinum and copper oxide catalysts heated at 450∼500° to oxidize sulpher dioxide. The amount of gases extracted from iron plate was measured by the reservoir method. 2. The determination of decarburizing rate by hydrogen saturated with water vapour showed that the rate of dry hydrogen was much smaller than that of wet hydrogen. 3. The carbon content of thin plate was well estimated by the amount of gas extracted from the plate which suffered proper oxidation and preliminary vacuum treatment. 4. As the activation energy of reaction rate between carbon and water vapor on surface is considerably large, the rate falls rapidly with the fall of temperature of hydrogen treatment.
The rate of gas extraction was measured by, (i) reservoir method and (ii) differential Pirani method. The diffusion constant of carbon was calculated from the rate of gas extraction as the solution of Ficks equation, provided that the boundary conditions of the equation were as follows: (a) the diffusion constant is independent of its concentration, (b) initial concentration is uniform everywhere in iron, and (c) the concentration of surface is always zero at t=0, As the diffusion constant obtained from gas extraction was always much smaller than that of carbon, the rate of reaction on surface was considered in place of the assumption (c), and represented the rate as: \[k=A[C]e−Q⁄RT\] The result obtained was satisfactory and the rates of reaction were represented as: 2 & K_α=7.4 ×I_o^27e^-48500/RT[C] & & molecules/cm^2 ·sec, & K_γ=7.4 ×I_o^27e^-52400/RT[C] && molecules/cm^2 ·sec.
A study on the same problem was published seperately by Dr. T. Matsuda and Dr. H. Imai. However, their explanation of the said problem was still open to more discussion. In the present paper, more detailed experiments were carried out for the mechanism by means of electric resistance, hardness and microscopic analyses. When alloys containing less than 25%Sn were quenched from 590°, the acicular structures appeared in them with the exception of the alloys quenched from below 590°. The decomposition of β or β′ could be arrested at the room temperature in the alloys belonging to the eutectoid composition, and electrical resistance, etc. reached a constant value. The electric resistance of the quenched alloys having the acicular structure was shown to fall from 200° to 320° and successively decreased to min. point at 320°. The arrested point appeared at the mediate temperature of 250°. In accordance with these facts, the tempering hardness increased from 200 to 320° in the alloys having the acicular structure and this tendency decreased at 250° in the alloys not having the said structure. The max. hardness of both kind of alloys was reached at 320° and they were decomposed at 400° due to the change of the second intermediate phase to (α+δ).
The author has investigated in detal the necessary conditions for a rapid polarographic determination of copper in iron and steel, and obtained a new simplified method requiring only 20 min, the outline of which is as follows: dissolve 1 g of sample in 10∼15 cc of HNO3(1:1), pour it slowly and stir to make 60 cc of the supporting electrolyte solution (4 N-NH4 OH, 1 N-NH4Cl), filter, take 5 cc of the filtrate, add 2 drops of 1 percent solution of gelatine as maximum suppressor and 10 drops of saturated solution of Na2SO3 as oxygen eliminator and copper is determined polarographically. The correction for the temperature is made by the use of a correction equation. This a new simplified apparatus for more rapid analysis is devised. By this method copper can be determined in about 10 minutes.
The cutting down of a metal plate by a shearing machine is thought to progress in the following ways: (1) The local compression of the plate, which is in contact with the shearing edge of the machine, by the external load applied on the plate through the machine; (2) by the increase of the load applied, the local contraction begins to take place in the plate at that place above mentioned; (3) which fact leads to the breaking down of the plate. The present author thinks that the cutting of the metal by a bite is a successive breaking down of parts of the metal by the shearing stress originated by the action of the bite. This author’s conclusion is drawn from the analogy of the structures of the broken parts of the materials and also from the hardness distributions of the materials respectively mechanically handled.
The hardnees and rate of deformation due to heat treatments of various different punching dies steels was studied. The moderate heat treatment of each steel for punching dies was ascertained, and rate of deformation was measured by the test piece of the bar and ring form. The rate deformation changes by the from and size of dies, kinds of steel and heat treatments. The rate of deformation of high carbon-high chromium steel is smaller than in other steels, and then steel containing Cr, Mn and W is comparatively smaller.
The influence of the bed coke’s height upon the carbon content in the produced pig iron was chiefly investigated in the present paper. The construction, dimension of the furnace and the charging materials were generally the same that of the previous paper, and the furnace was operated about 17 hours continuously for each experiment. The height of the bed coke and the ratio of the charging coke to the scrap were varied respectively. On the other hand, the ratio of lime stone to the scrap was always 20% to it. In order to obtain the carbon content about 4% in the products by means of the author’s operation, the following conditions were suitable, namely, the height of the bed coke was 1.5 meters and the coke ratio was 70%. Even though the furnace was operated with 60% coke ratio, the carbon content in the products would be increassed in the special case which was more than 2 meters height of the bed coke. The result of the carbon content was increased with the coke ratio and the amount of the pig iron scrap added to the charge was shown in the previous paper. The same behaviour was concluded in the present paper.
Although no satisfactory explanation of the action of doping can be given, its effect on sintering seems to be that when doping reagents volatilise, they separate grains resulting in finer grain size than pure tungsten ingot. Moreover, the impurities as FeO may appreciably be reduced by the volatilisation of doping reagents. We prepared two lots of tungsten powder which contain 0.4%SiO2, 0.2%K2O and 0.03%Al2O3 to WO3 and sintered the pressed ingots using sintering currents of 65%, 75%, 80%, 85%, 88%, 90%, 92% and 95% to fusion current. The changes in shrinkage, hardness,apparent density, electrical resistivity, grain size and decrease of nonvolatile residue and FeO during sintering have been studied. (1) Sample No. 1, which is finer than No. 2, showed the easy sintering. (2) From the hardness and grain size measurement, it was supposed that the temperature was the highest at central part and then upper and lower part of an ingot. (3) The effect of doping reagents on the restraining grain growth during sintering is remarkable—the grain size of pure tungsten ingot sintered at 90% current is about 100 times as large as that of doped ingot. In consequence of the fact that grain growth takes place rapidly between 65∼80% current, it is possible to control the gain size at this sintering current. But we could not find conspicuous purifying effect during sintering on the decrease of impurity (FeO). The composition of residue is about 50%SiO2 and 40%Al2O3.