The procedure for a perfect, rapid and accurate determination of orientations of trigonal bismuth single crystals by the use of light figures produced by their etched {111} and {uuv} planes was worked out.Full accounts are given of the geometrical relationships, procedure, etching directions, directly measurable range and kind of angles, representation of crystal orientations, accuracy, and actual examples. Though bismuth crystals show complex light-figure phenomena, different from cubic crystals and from hexagonal zinc crystals and,consequently,the procedure of orientation determination by the light-figure method becomes somewhat complicated, the perfect determination of crystal orientations can be made with an accuracy within ±0.2.°

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The relation between working temperature (T°K), degree of deformation. (γ%) and the lapse of time before recrystallizing (t sec.) was obtained as the curves, as shown in Fig. 1. Specimens were carbon steels, Cr steel, Cr-Mo steel and high speed steels. Considerations were given on these curves and the empirical formula was given. The results are as follows :
\ oindent(1) The relation between logt and 1⁄T, under γ=constant, came out nearly as a straight line for every steel. Activation energies were calculated from them.
\ oindent(2) It was ascertained that the relation between t and γ could be expressed by the following formula for every steel, \[lnt+Aγ^1⁄n=B\] where, A and B depend on the material and the temperature, and n varies with the material but not remarkably with the temperature.

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High speed steel specimens were worked by torsion at the temperature of 1000∼1200°, and austenite grain-growth was observed with microscope. Austenite grain-boundaries were revealed by keeping the specimens at 800° for 10 minutes, the temperature bringing the nose in S curve. The outlines of the experiments are as follows :
\ oindent(1) The relation between the degree of deformation, grain size and the working temperature was measured.
\ oindent(2) The progress of recrystallization or grain-growth with the lapse of time after hot working was observed.
\ oindent(3) The relation between the degree of deformation and the lapse of time before recrystallizing was found out.
\ oindent(4) It was observed that the successive alternating working diminished the capacity of recrystallization.
\ oindent(5) Coarse austenite grains were incapable of being recovered by the heat treatment.

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Erscheinung des Erweichens auf der eutektischen Zusammensetzung von Legierungen eines niedrigen Schmelzpunkt durch Kaltbearbeitung wurde vielmalig untersucht, ohne jedoch das Wesen ganz wieder zu klären. Es wurden daher Versuche auf aller Zusammensetzung des Zinn-Blei und auf einiger Zinn-Zink Legierungen nach verschiedener Behandlung.
Die Kaltbearbeitungsabhängigkeit der Streckgrenze und Biegung wurde mit Hilfe der biegenden Prüfung untersucht.
Die Hauptversuchsergebnisse sind wie folgt; Im Verlauf der geringen Kaltbearbeitung von Zinn, Blei und dessen Mischkristallgebiet wurde die Härtunggefunden. Bei den eutektischen Legierungen wurde die Härte mit steigendem Verformungsgrad abgenommen.
Die eutektische Struktur ist nicht die einzige, die das Erweichen durch Kaltbearbeitung verursacht, aber ist die erste, die das Erweichen durch Kaltbearbeitung fördert.

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We analysed four stages of cooling process during quenching in the liquid and found the relation between the properties and the cooling ability of liquid from the observation of the cooling processes reported in the 2nd report.
In the 2nd stage the vapor film breaks down eary at high temperature when the molecules contained in the liquid may be adsorped on the surface of solid, then the boundary tension decreases, and the vapor pressure of liquid is low and the heat of vaporisation of liquid is large; that is,the “Characteristic Temperature”, breaking down the vapor film, becomes higher. And the higher the characteristic temperature is, the more rapidly cooling in this stage becomes. In the 3rd stage, the higher the characterisitic temperature and the lower the boiling point is, the more rapidly the cooling becomes. We may say that the cooling ability of liquid depends upon the characteristic temperature, because the cooling ability of liquid is almost determined by the cooling in the 2nd and 3rd stages.
The most excellent quenching liquids must have the following properties.
(1) The liquid contains so many molecules to be adsorped,its vapor pressure is so low and its heat of vaporization is so large that its characteristic temperature is above 700°. (2) The boiling point of the liquid is about 300°. But we must choise the quenching media in accordance with kind, size, shape and use of the steel, after comparing the process of transformation of the steel with the cooling curves of the media.

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Using 18% Chromium steels containing 0.03∼0.27%C and 0∼3.26%Ti, several properties were studied. The self hardening property vanishes with the addition of more than 0.25% of titanium, irrespective of carbon , and with further addition of titanium the hardness gradually increases. The temper-hardening is observable in specimens containing more than 2.5% titanium and 10 times carbon content. The grain size of ferrite is refined and its growth at high temperature is retarded with the addition of about 0.25%Ti. One or two kinds of carbide, Cr₄C and TiC, are obsevable, according to titanium and carbon contents. Acid-resistivity with conc. boiling HNO₃ solution and corrosibility with 3%NaCl solution were tested, Impact resistance markedly increases with the addition of 0.25∼0.50%Ti, irrespective of carbon content and decreases with further addition of titanium.

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In a study of tempering mechanism of quenched β-tin bronze, H. Imdi reported that mechanism β→β′→β″→α+δ, assuming the two intermediate states, β′ and β″.
The present investigation was carried out to study in detail the facts which remain unexplained by means of microscopic examinations and X-ray analyses.
The results obtained are as follows:
\ oindent(1) β′ is the 250° tempered state and consists (β+α) (in the case of (A) 25.44%Sn alloy) or (β+δ) (in the case of (B) 27.80%Sn and (C) 28.71%Sn).
\ oindent(2) β′ microstructure of (A) alloy has two kinds of long thin parallel bands each of which has a striated furrowlike striated relief. δ appeared in the matrix and boundary of β in the case of β′ of (B) and (C) alloys.
\ oindentFrom X-ray analyses, the present writer is led to believe that the above abnormal structures of β′ were produced by the plastic slip of β and β→α transformation.
\ oindent(3) It is thought that β″, which resembles β′ in microstructure with the exception of easier corrosion than β′, is the changed state of β′ in atomic arrangement of the thermal distribution of electrons of β, from the facts β″ gives diffraction patterns containing lines which do not belong to β′ (β+α or β+δ) and that β″ gives the lowest specific resistance value on tempering.

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The isothermal transformation for 22,23.5,25,26 and 28%Sn-Cu alloys were tested microscopically and the isothermal transformation diagrams were obtained as shown in Fig. 2. The processes of eutectoid transformation in alloy of hypo-eutectoid composition were upper-bainitic at the temperatures above 350° and lower-bainitic at the temperatures below 350°. The martenstic structures appeared below 150° and 100° in 22 and 23.5%Sn alloys, respectively. In 25 and 26%Sn alloys the martenstic structures were obtained by immersing them in liquid oxygen. The processes of eutectoid transformation in alloys of hyper-eutectoid composition, which are pearlitic, being accompanied by pro-eutectoid precipitation of δ at the temperatures not far below the eutectoid temperature,could not be examined sufficiently because the transformation was very rapid and the sample was not etched uniformly.
The changes in structure on tempering of quenched alloys were also tested microscopically. When the tempering temperatures were below 300° distinct precipitations were not recognized and only retained β and became sensitive to etching, but when the tempering temperatures were above 350° δ precipitated from α_m(=β′) and retained β.
Above results could be explained favorably on the basis of meta-stable diagram shown in Fig. 1.

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The mechanism of corrosion of Iron in acid river water was investigated, and the following results were obtained :
(i) The rate determining step of corrosion reaction was the diffusion of hydrogen ion. (ii) In the range of pH less than 4.0, the corrosion of iron in stagnant solutions was diffusion control of hydrogen ion at first, but it changed to diffusion control of oxygen as time elapsed, owing to the difference in diffusion velocity. (iii) By the calculation by the diffusion theory, the corrosion velocity of iron in acid viver is to be a maximum at pH 4.4. The observed value was pH 4.3. (iv) The activation energy of corrosion reaction on iron in acid river water (pH 3.0) was about 1.4 kcal/mol.

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The authors studied the cathodic protection of mild steel and gun metal in acid river water. The protection by the use of zinc was almost ineffective and the protectjon with external E.M.F. required very large protective current density. The effective distance of zinc protector was determined by measuring electrical conductivity and current density in corrosion cell, On the other hand, Laplace’s equation for voltaic couple was solved approximately in the simplest case. The solution was in qualitatively good coincident with the experimental results.

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Selenium and tellurium were respectively reduced to metallic state,using titanium,molybdenium and chromium reduced with liquid zinc amalgam, and determined by weighing them.
Selenium was determined successfuly after the reduction to metallic state with the lower valence titanium,molybdenum and chromium. By the same procedure, tellurium was determined successfully only with chromium, and with the the rest any available procedure has not been found get.

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