Continuous cooling transformations in a low cardon 1.1/4 Cr 3/4 Si 1/2 Mo steel and a 2.1/4 Cr 1 Mo steel have been investigated to obtain the necessary information for heat treatment of these steels. Continuous cooling transformation diagrams were obtained by varying the cooling rates, from 10 to 15,000 sec. expressed in cooling time from Ac₃ to 500°. Transformations were determined principally by using dilatometry and metallographic observations. CCT diagrams for both steels are similar in shape in which the transformation ranges are in the high temperature range and low temperature range and they are separated by the non-transformation range. However, many differences in critical cooling rates and in the constitution of the resultant structures at the fixed cooling rates were observed between the two steels. They are shown and compared quantitatively The bainite transformation range extended to the extremely high cooling rate side and its products exist in the resultant microstructures over a wide range of cooling rates. The initial temperature of the bainite transformation is lowered by the precedent proeutectoid ferrite formation on continuous cooling. The larger the amount of proeutectoid ferrite, the more the bainite formation temperature is depressed, however, its depression is remarkable after more than 50% proeutectoid formation The phenomenon is mainly due to the enrichment of carbon into austenite which is the result of proeutectoid ferrite formation. Stabilization of untransformed austenite due to very slow cooling is not likely to occur and the aforementioned beginning temperture of bainite is very close to B_S which is determined by the chemical composition of untransformed austenite.

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The authors are attempting to clarify the fundamental factors relating to cermet making from the view points of surface and interfacial tensions. The anthors’ previous paper described the surface tensions of pure metals and alloys, and this paper reports experimental results due to effects of dissolved sulphur, oxygen, slenium and tellurium on the surface tension of liquid copper. The results obtained are as follows: The elements of group VIb of the periodic table are highly surface active in liquid copper. The effects of negative elements on the surface tension become more severe with lowering temperature. The degree of adsorption of these negative elements on the liquid copper surface has been calculated, and from the results each adsorption-layer is considered to consist of a monolayer of negatives ions attracting copper ions.

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An investigation has been made on corrosion of binary copper alloys in water at high temperature and steam under saturated pressure, 86 kg/cm², at 300°C for 250 hours, using an autoclave. Binary alloys containing zinc (10, 30, 40%), aluminium (1, 6, 10%), silicon (1, 3, 4%), manganese (1, 5, 9%), nickel (5, 8, 15%), or tin (2, 6, 12%) were used as rolled and annealed strip. After the corrosion test had been made, tensile test, microscopical examination and X-ray analysis of the corrosion product were performed and the following results were obtained. (1) Cu-Zn alloys suffer from layer type corrosion. (2) Cu-Al and Cu-Si alloys of α single phase suffer from intergranular corrosion. Cu-Al alloy of duplex phase suffers from selective oxidation on second phase. (3) Cu-Mn, Cu-Ni and Cu-Sn alloys are almost immune to corrosion but Cu-Mn and Cu-Ni alloys have a little susceptivility to intergranular corrosion.

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In dieser Untersuchung wurde die Beziehung zwischen dem Gefüge und der Vickershärte in Längsschnitt sowie dem Verhaltnis (H_L/H_Q) der Härte, die von jeder Diagonale in Längs- und Querrichtung des Eindruckes berechnet wurde, in verschiedentlich wärmebehandeltem und gezogenem Stahldraht aufgeklärt. Nämlich grösser wird die Zunahme der Härte durch Ziehen nach dem 1. Zug mit abnehmendem C % und Wärmebehandelfestigkeit und nach mehren Zügen mit zunehmendem C % und Festigkeit. H_L/H_Q bleibt mit steigender Ziehverformung anfangs unter 1 und dann steigt über 1 langsam auf, aber in weiteren Verlauf des Ziehens bleibt unveränderlich. Und mit steigendem C % nimmt H_L/H_Q unter 90% Quersch-nittsabnahme zu und darüber ab. In Bezug auf der Wärmebehandlung, zeigt der luftpatentierte Draht den grössten Wert von H_L/H_Q und der geglühte den kleinsten.

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The effect of halide ions on the anodic passivation of zirconium in acid, neutral and alkaline solutions was studied. In the presence of fluorine ion, dissolution of zirconium was observed in acid solution and pitting corrrosion in neutral solution, but in alkaline solution zirconium was not attacked. In the presence of chlorine or bromine ion, pitting corrosion of zirconium was observed in solutions of any pH value, but pitting by chlorine ion and that by bromine ion was prevented comparatively by presence of nitrate or nitrite ion and hydroxyl ion, respectively. Neutral iodide solution, without any oxyanions, can pit zirconium, but the solution containing some oxyanion caused no pitting. Oxidizing agents promote the start of pitting, but general anions (e.g. SO₄²⁻, SO₃²⁻, NO₃⁻, NO₂⁻, OH⁻) prevent corrosive action of halide ions. The pitting corrosion potential, 0.20-0.23 V (vs. S.C.E) for chlorine ion 0.1 mol/L, 0.45-0.50 V for bromine ion, and 0.82-0.86 V for iodine ion, did not vary with current density. A linear relation exists between the pitting corrosion potential and the logarithm of the halide ion concentration. Halide ions cause a greater number of smaller pits in the order of Cl⁻<Br⁻<I⁻.

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Thermodynamic properties of lead-bismuth liquid alloys have been examined by making use of the electromotive force method. Electrode concentration cells of the fallowing type were used throughout the temperature range of 370 to 480°C:
Pb(liquid)⁄PbCl₂, KCl-LiCl⁄Pb-Bi(liquid)
The experimental results indicate that this system shows a negative deviation from Raoult’s law and that the excess extropies are practically zero. Thus the excess free energy and excess enthalpy can be written as follows:
G_m^′=H_m^′=−1,150x_Pb·x_Bicalmole⁻¹
The phase diagram of this system is discussed on the basis of the present results.

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It is not difficult to prepare the manganese-zinc ferrite having a high permeability. But such a ferrite is also accompanied with a considerable loss at high frequencies because of the high conductivity. For improving the practical characteristics, i.e. reducing the loss and increasing the initial permeability various impurities were added to the manganese-zinc ferrite Mn_0.68Zn_0.21Fe_2.11O_4+δ. The simultaneous addition of CaO and SiO₂ to the ferrite was found to be effective for this purpose. The impurities change the electrical and magnetic properties as well as the sintering grain structure. The relation of these properties to the grain structure was studied. It was found that the small loss of the ferrites containing proper amounts of CaO and SiO₂ was due to the grain structure consisting of fine grains separated from one another by high resistive layer. The excess of SiO₂ provokes the discontinuous grain-growth forming so called duplex structure, which is unfavourable in reducing the loss at high frequencies. The excess of CaO reduces the permeability remarkably. Based on the experimental results obtained in this study an excellent ferrite with a very small quality-factor, tan δ⁄μ₀<2×10⁻⁶ at 100 Kc, was prepared.

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The lattice diffusion and the grain boundary diffusion of cobalt in γ-iron were measured in the temperature range from 1140 to 1340°C by using the radioactive tracer Co⁶⁰ and by a lathe-sectioning method. The grain growth in polycrystalline specimens of γ-iron was also investigated and a rapid grain growth treatment was taken during diffusion annealing. The data were analysed by the theory for grain boundary diffusion based on the instantaneous source model, previously developed by the present author. The lattice diffusion coefficient D was found as
D=1.25exp(−72,900⁄RT)cm²sec⁻¹,
while the grain boundary diffusion coefficient D′ as
D′=0.5exp(−33,000⁄RT)cm²sec⁻¹.

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Magnetoelastic interaction, between stress around dislocation lines and magnetostriction was investigated. When a magnetic wall passes across dislocations, energy due to this interaction varies with its position. Variation of this energy changes by 10⁻⁵ ergs/cm/dislocation in order of magnitude. Supposing that this energy change is the main origin of variation of internal energy with the wall position a formula of coercive force and initial susceptibility are deduced. The calculated values of coercive force and initial susceptibility of iron are 0.1 Oe and 40, respectively. These values seem to agree well with the observed values for annealed iron. Temperature dependence of coercive force and its variation by plastic deformation are interpreted by the present theory.

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