Fe-Co system alloys used for telephone receiver diaphragm, called by the name “Permendur”, must be cold-rolled easily to very thin sheet, but generally Fe-Co alloys are brittle and cannot be cold-rolled readily. When a few percent of vanadium was added by quenching from about 900° without influencing the magnetic properties, it can be cold-rolled.
Mechanical properties such as hardness, elongation, tensile strength and etc. vs. quenching-temperature curves increase all from about 600° and attain a maximum at about 700∼1100°. It is inte resting to note that hardness has a maximum at 800°.
Fe-Co (50%) alloys has FeCo superlattice, This in confirmed by X-ray analysis. But on the contrary to Ni-Fe (38.5%Ni) alloy, its magnetic properties decreases by quenching : Fe-Co (50%)-V(2%) alloys has decreased after quenching, and the magnetic properties vs. quenching-temperature curve has conspicuous features. By varying Co% at constant V%, the excellence of 50%Co alloy was confirmed. About this alloy B-H curves were measured at various annealing temperature, annealing time. After this alloy was cold-rolled its magnetic properties increases generally. This alloy has strong direction dependency measured by torguemeter after cold-rolling, but when annealed, it vanishes perfectly.

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The improvement of present telephone receiver depends chiefly on its magnetic circuit, and above all on the diaphragm. We have deduced the “goodness of a diaphragm G from electric-power sensibility, which, is proportional to the flux density B₀ and to the square root of reversible permeability at the using state. When G is compared on various magnetic materials, pure iron, Si-steel, 45 permalloy and Fe-Co-V alloy, the last one is excellent. Pure iron is used nowadays as diaphragm, we showed its diaphragm characteristics at various heat treatments, and best results are obtained by annealing at about 550°.
G is proportional to factor A, as A determines the goodness of diaphragm also. A increases with the decrease of gap length between diaphragm and pole piece, but because of magnetic saturation, drops again after a maximum.
The best values of A shows also Fe-Co(50%)-V(2%) alloy.

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The author studied the effect of keeping time in some temperature above the transformation point from quenching temperature on the hardness, microstructure and cutting durability of high speed steel. In the ca e of cooling from quenchng temperature, the hardness and cutting durability are decreased more prominent as the keeping time in the temperature above the transformation point are increased, and change of microstructure are observed. The cutting durability of these are inferior to oil quenched specimen commonly.

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The deformation often seen in the hot bath quenching is utilized in restoring the shape before the transformation begins. In this report, the relation between the 1st and 2nd Ar″ transformation and the deformation of the super cooled austenite at 400∼600° during the hot bath quenching has been investigated by the measurements of dilatation, magnetic properties and hardness. The deformation during the hot bath quenching raises the 1st transformation point on cooling and increases the amount of martensite, so the hardness and the magnetic properties of predeformed specimens are increased with the deformation degree of specimens both tempered and quenched. The higher the temperature of deformation is in the region of 400∼600°, the more these influences can be seen significantly. Moreover, these effects are intensified by holding for a long time at the temperature of hot bath in order to release the stress produced by the deformation, and remained even by the step up tempering to about 800°. It has been discussed that the deformation of the supercooled austenite during the hot bath quenching contributes to the coagulation of carbides, and therefore, effects on the stability of the austenite and on the subsequent Ar″ transformation.

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It has been shown that the heating rate in annealing white iron, whose compositions are of malleable iron, influences its graphitizing phenomena remarkably; the rapid heating such as by dipping in molten lead causes the refinement of the graphite nodules by subsequent annealing, which was reported previously, the moderate rate of heating as the heating to the graphitizing temperature in about 10 hrs. results in the coarsening of the particles, and the slow heating as in the case of heating to the graphitizing temperature in about 40 hrs. causes to increase the graphite nodule number.
As mentioned above, the size of the graphite particles by annealing becomes larger as the heating rate increases, and then smaller by the extremely rapid heating, which is probably explained by the relations among the stability of cementite, its growth and the heat-treatment. It is clear that the large number of graphite particles may be caused by the graphitization of cementite without its grawth.
The number of nodules is affected by chemical compositions and freezing conditions. The difference of nodule number between the rapidly heated samples by dipping in lead bath and the very slowly heated samples is smaller at the cast state in sand mould than at the cast state in metal mould. Iron containing 0.9∼1.1%Si showed also smaller difference than that containing about 1.3%Si. The difference of nodule number between the rapidly heated samples by dipping in lead bath and the samples heated in about 10 hrs. to the annealing temperature is smaller in samples cast in sand mould than in samples cast in metal mould. Samples with a few percentage of Al or Mn show almost no difference in the industrial rate of heating.

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White iron and malleable iron therefore were quenched from above the critical range to clarify the relation between the accelerating effect on the graphitization and the quenching treatment in the former, and to estimate the surface hardenability in the latter.
The graphitization during heating for the quenching does not impede the graphitization in the subsequent annealing. The quenching temperature of malleable irons for the surface hardening is appropriate at above or near its eutectic temperature. The surface hardening can be achieved by rapid heating followed by oil quenching from the superheated state before the partial melting begins. In the same malleable iron but differing in its graphite size, the hardenability is greater in irons having smaller graphite.

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The zinc coating by applying “Molzin Process” to malleable iron, the micro-structure of which is silico-ferrite+graphite differing from the ferrite in pure iron, has been studied. The layer of the coating was found to be single or double having graphite-nodules and have a better cohesion than that in pure iron. The better cohesion may be attributed to the mode of the zinc penetration and the nature of the layer ; as zinc penetrates deeper around graphite-nodules, and the irregular boundary between the matrix iron and the coating is easily formed. Besides the compound layer on pure iron, in which fractures by could working are often seen, is not found in this case. The optimum depth of the coating, 0.02∼0.08 mm, can be obtained by heating at 450∼650° with 5%Zn powder for an hour. The oxide powder must be such as not combining with zinc at the treating temperatures and having about 100 mesh. In the experiment the quantity of the mixed powder used per unit area of specimens was 10∼20 g/m². The impurities such as Fe₃O₄ or Fe₂O₃ in the powders showed bad effects. For instance, when treated with 10%Zn powder, the coating can not be formed if Fe₂O₃ exceeds 5% in the oxide powder. The quantity of remained zinc in the powder after the treatments repeated four time was found to be 85%Zn of the initial zinc in the powder. To obtain the similar coating every time by the repeated use of a mixed powder containing 5% of zinc 550° for an hour, fresh zinc of 2% of the used powder must be added before the next treatment, and the fresh zinc to be added must be 4% if the mixed powder contains 10% of zinc. It was shown in the Preece Test that the coating was very uniform with high number of dipping. The good durability of the coating has been confirmed by the weathering and the corrosion tests in 1%NaCl solution.

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This report has been written as the first section of the major subject “The Studies on the Polished Surface of Metals.” The experiments have been carried out for the purpose of investigating the cause of appearance of halo-ring patterns, which is almost common to the polished surfaces of various kinds of metals, in a cathode-ray diffraction.
With respect to copper, the author observed an obvious effect of polishing accompanying the simple grinding operation. This effect is limited in a very shallow superficial region, which appears to have been originated from the local melting. By the succession of fine grinding process, the structure of the surface transforms itself by two stage. The first one has a very peculiar structure, which might be taken to be a simple triclinic lattice constructed by Cu₂-molecules, being designated as the “transitional lattice” by the author. This structure retransforms itself into the second one, which is much like the chain structure of organic molecules, and shows the characteristic tripoint reflection patterns, the dimensions of which being almost the same as those of the halo-ring patterns cited above.

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Relating to copper, the author observed the molecular binding of Cu-atoms formed by five grinding or polishing. In the unfinished stage of polishing, these molecules (provisionally so-called) construct the characteristic form of lattice, or stand in the certain orientational axis, which reflect the characteristic patterns as described in the previous report. When polishing comes to the final stage, these orientational structures collapse and the positions of Cu₂-molecules become haphazard. By assuming simple cubic arrangment for these molecules, the calculated positions of statistical maximum of intensity in electron reflection show a good coincidence with the results of observations.
Following the interpretation of the present writer, the halo-ring patterns by polished surface of metals in electron diffraction are not due to the contour of surface, but to the inner structure though limited in very thin layer of surface, and that structure, so far as relating to copper, should be taken as the at-random arrangement of molecular binding of Cu-atoms.

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The internal structure of rolled zinc is believed to be as follows: the hexagonal base lies nearly parallel to the plan of rollig, i.e. fibreaxis coincides with the hexaganal axis and lies in the plane containing the direction of rolling and normal to the plane of rolling, but the axis being scattered about 20° to the direction of rolling and also to opposite direction. This was true in the specimen rolled in spring and summer and the angle decreases with the rise of the temperature of rolling. Even in the specimen rolled in summer, some crystallites have their hexagonal bases in the direction perpendicular to the plane of rolling exist. But these crystallites disappear after several days and majorities of crystallites become nearly parallel to the plane of rolling. This is because the direction of crystal growth is perpendicular to the hexagonal axis and this fact was also proved from the measurement of Young’s modulus, namely, immediately after rollig, it is 7.71×10⁻¹¹ dyne/cm² and after 4 days, 8.05×10⁻¹¹ dyne/cm². If the specimen was rolled in winter, the crystallites have their hexagonal base in the direction parallel and perpendicular to that of rolling and both lying parallel to the normal of the plane of rolling predominate. The relation between these two sorts of crystallites nearly coincides with that of mechanical twin. Therefore, we can conclude that in cold state deformation of zinc is accompanied by the formations of mechanical twins, and the slip parallel to the hexagonal base is not so significant.
Above results are true for specimens both rolled parallel and perpendicular to the axes of columnar crystal grains. Zinc will much easily be worked if the direction of rolling coincides with the axes of long columnar grains.

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The published data, heretofore, on the structure of carburized Th-W, are not sufficient for the theoretical study of the effects of carburization on the activation. We inspected microscopically a lot of carburized filaments, including decarburized one, under dry hydrogen and in low and high vacuum. The characteristic structures are; (1) columnar one after carburization under hydrogen atmospher. (2) laminated one having a decaburized sheath with fine grain on surface, (3) massive and laminated one after heating in high vacuum, (4) coarse-grain one without carburized sheath.
Type (1) suffers great variation of resistance at room temperature by exhaustion. We obtain type (2) only by decarburization in hydrogen. By the microscopic studies we concluded that the laminated structure is a eutectic one and has less carbon content than the massive structure with the stoichiometric composition of W₂C (3.16%C).

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It is generally accepted that the degree of carburization and the hue of the surface have an important effect upon the electron emission of carburized Th-W filament. Experimentally we analysed these facts, referring to the data formerly published. The hue results from the thin layer of the free carbon on the suface. We measure the free carbon in the filaments having different degrees of variation of resistance at room temperature before and after exhaustion. The results of the statistical study about the commerical transmitting tubs in production and of the observation of activation phenomena of experimental diodes, it may be summerised as follows :
(1) The layers of free carbon make the activation rate and further the total emission decrease. (2) Both the fine grained structure and the removal of carbon layers enhance the electron emission of decarburized filaments. (3) It is supposed that ThO₂ is decomposed partially already during carburization.
We are justified in saying that the electron emission characteristics is not directly related to the degree of carburization, which is defined only by the ratio of cold resistance before and after carburization.

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In this report, a research has been made concerning the change of the hardness and the crystal growth of Se in accordance with the time of heat treatments by means of the Marten’s scratch hardness tester and of the X-ray method, respectively. And we measured the surface tension in the melting state at each temperatures with the dropping method.
As was shown in Fig. 1, the Marten’s hardness diminished rapidly in 5 minutes, and then after 20 minutes, it began to increase until 4 hours had elapsed. This tendncy was almost opposite to that of the impact value.
By the X-ray method, we found that, in the first stage of the treatment, the crystal had some preferred orientation (see Fig. 2-a), and the internal strain (Fig. 3-a). And then in the second stage the strain disappeared (Fig. 3-b), the crystals showing a random orientation and a grain growth (Fig. 2-b) as well.
When the Debye-Scherrer’s method was applied in the first stage of the treatment, the lattice constant of a-axis expanded and that of c-axis contracted as compared with those in the normal state (see Table 1).
When we measured the surface tension,it satisfied the Eötvos empirical relation up to 300°, while it decreased rapidly around 320° and then gradually diminished (Fig. 5).

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There are two methods for determining sulphide sulphur in slags, namely direct method or evolution method and indirect method. The principle of the former is that slags are treated with hydrochloric acid and H₂S evolved is absorbed in absorbing solution and determined. The principle of the latter method is that total sulphur and sulphate sulphur in slags are respectively determined and the differerence between those two values is taken as representing sulphide sulphur. In order to decide which f these two methods is better as the method for determining total sulphide sulphur, we applied both methods to blast furnace slags and basic open-hearth slags, and found that values obtained by the latter method were always higher than those obtained by the former. An investigation into the cause of this disagreement clarified the fact that slags contain more or less HCl-insoluble sulphide which can not be determined by direct method, but can be determined by indirect method ; and arrived at the c nclusion that indirect method is more reasonable than direct method from the point of view of the determination of total sulphide sulphur. Moreover, we found that in blast furnace slags 1-3% of total sulphur were contained as sulphate while with basic open-hearth slags the content was 2-12%.

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The authors made the determination of water-soluble sulphate sulphur, HCl-soluble sulphate sulphur, HCl-insoluble sulphide sulphur, HCl-insoluble sulphate sulphur, and HCl-soluble sulphide sulphur in iron ores such as Takai, Gumma, Kamaishi, and pyrite-and pyrrhotite-cinders, and, using the data obtained, tried to estimate the amount of the error in FeO values determined by the usual method which arises from the reduction of ferric iron by H₂S evolved from soluble sulphide and the interference of soluble ferrous compounds, especially ferrous sulphide, other then FeO. According to the results,it was found that among the materials investigated the error estemated is nearly zero only in the case of Gumma ore, which does not contain any soluble sulphide in it, while in other cases it can not be ignored, especially in the extreme case of pyrite cinder where it amounts to nearly 100%.

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A new copper mould devised by Derge to take a wedge-shaped and therefore rapidly chilled sample for rapid vacuum fusion analysis of molten iron and steel for total oxygen content during the steel making process was made and tested by the authors, and the following throughout defects were found : (1) the sharp bottom part of the cavity of the mould often could not be completely filled with molten iron and therefore the available chilled and bright part of sample taken was often too small to effectuate accurate analysis ; (2) the heat capacity of the mould was so small that the mould became conaiberadly hot,not permitting to touch with bare hands even after it was used only once, and this made it impossible to continue sampling with the same mould in spite of Derge’s pretension. Samples taken with Derge’s mould were analysed for oxygen by the Gakushin hydrogen reduction method which is expected to give nearly the same value as the vacuum fusion method when oxygen is contained mainly in the form of iron oxide in samples. The values so obta- ined almost agree with those obtained by the Gakushin rapid method for determining oxygen in molten iron and steel, orthe modified Herty’s aluminum method.In using the Gakushin rapid method it was found. (1) blank values were sometimes nearly equal to or even greater than true values and therefore they could not be ignored ; (2) the use of not only ashless but finer filter paper su h as T\={o}y\={o} filter paper No. 5c or No. 6 is preferable, because ordinary ashless filter papers are not so fine and fail to catch finer alumina particles.

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