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Volume 17, Issue 5
Displaying 1-12 of 12 articles from this issue
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Makoto Endoh, Kazuyosi Nisino1953 Volume 17 Issue 5 Pages 205-209
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDilatometoric studies on the isothermal transformation of Austetenite into Martensite in various carbon steels were carried out. The results are as follows: (1) In the Bainite range, the rate of lowering of Ars″ point, the biginning point of the transformation in cooling after Austempering, is slow even when the percent of Bainite transformed is 70%, but after the percent has exceeded 70%, the lowering rate of Ars″ point is greatly quicked. (2) In the martensite range, on the other hand, the lowering rate of Ars″ point is fast without so much transformation, and is greater than the rate of transformation in isothermal treatment. The temperature coefficient of the rate of transformation becomes small, and that of the lowering rate of Ars″ point becomes large, as the cardon content in the steel increases. (3) The lower the rate of transformation in isothermal treatment is, and the faster the lowering rate of Ars″ point is, the greater becomes the amount of retained Austenite. (4) It is considered that the lowering of Ars″ point in Bainite range is caused chiefly by the lattice defects in Austenite, while in the martensite range it is due to the contraction caused by the change of Martensite to Bainite and the age hardening of Austenite. (5) If the cooling rate in the martensite range is fast, Austenite around Martensite suffers much plastic deformation corresponding to lattice transformation, because of the increase of the amount transformed per unit time, in the result, the transformation is accelerated, and the amount of retained Austenite decreases.View full abstractDownload PDF (790K) -
Yunoshin Imai, Teturô Ishizahi1953 Volume 17 Issue 5 Pages 209-212
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present investigation has been carried out to ascertain the effect of nitrogen on the impact-resistance and the decrease of impact-resistance by cold-work. The effects of nitrogen were examined by charpy impact test on steels containing C 0.15%, Mn 0.30%, Si 0.15%, N2 0.003∼0.030%. From the present investigation the following results were obtained; [(1)] The impact resistance of milo-steele at 0°C decreased with the increase of nitrogen content. [(2)] The decrease of impact resistance after cold work becomes conspicuous as the nitrogen content increases. [(3)] There is a clear correlation between the decrease of impact resistance by cold work and the strain-aging due to nitrogen. [(4)] By the addition of Al or Ti as fixers of nitrogen it becomes clear that the impact resistance increased and the rate of decrease in impact resistance decreased.View full abstractDownload PDF (605K) -
Yunoshin Imai, Tetsurô Ishizaki1953 Volume 17 Issue 5 Pages 212-216
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn continuance to the 13th report, the present investigation has been carried out to ascertain the effect of nitrogen and phoshporus on the impact-resistance and on the decrease of impact-resistance by cold-work. The experiment was done on specimens containing C 0.15%, Mn 0.35%, Si 0.15%, P 0.10%, N2 0.003∼0.030% or C 0.15%, Mn 0.35% Si 0.15%, N2 0.004%, P 0.003∼0.3%. From the present investigation the following results were obtained: [(1)] By the addition of phosphorus, the impact-resistance was reduced, but the degree of reduction is not so strong in the specimens containing less nitrogen. [(2)] Phosphorus induced a decrease of impact-resistance after cold work, but the degree of decrease is not so strong in the specimens containing less nitrogen. [(3)] In both the cases whether the steel contained phosphorous or not, the same effect of nitrogen was recognized. [(4)] The strain-aging due to nitrogen increased severally at the range of nitrogen content from 0% to 0.006% in 0.003% P-steels, from 0 to 0.004% in 0.05% P-steels, and from 0 to 0.0035% in 0.1% P-steels. [(5)] By the addition of Al or Ti as fixere of nitrogen in steels containing phosphorus, it became clear that the impact-resistance increases, and the decrease of impact-resistance by cold work was reduced.View full abstractDownload PDF (776K) -
Masayoshi Tagaya, Imao Tamura1953 Volume 17 Issue 5 Pages 217-220
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe cooling curves of silver cylinder quenched in several samples of pure hydrocarbon prepared by the fractional distillation and other chemical operations from mineral oils were measured. The results are as follows: Among the oils of the same series, the larger the molecular weight is, i.e. the more the flushing point and the viscosity rise, the higher are the characteristic temperature and the beginning temperature of the convection stage. Among oils of nearly the same molecular weight, the oils consisting of hydrocarbons not of paraffin series have higher characteristic temperatures, higher begining temperatures of the convection stage and higher cooling velocity in the convection stage compared to the oils consisting of hydrocarbons of pure paraffin series. It seems that the cause of these facts is attributed to the vapor pressure, the boiling point, the ability of adsorption of constituent molecules and the temperature coefficient of viscosity of oils.View full abstractDownload PDF (616K) -
Hidehiro Gotô, Yachiyo Kakita1953 Volume 17 Issue 5 Pages 220-223
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSOwing to the necessity of simple microdetermination of tin in small amount of iron and steel samples, its photometric determination, was studied. Fundamental experiments were carried out on the colour reaction of stannous salt with cacotheline to obtain the suitable conditions for the determination of tin separated from actual metal samples. After the stannous solution was reduced by aluminium in the stream of carbon dioxide, cacotheline was added to it. The photomeric measurement was made using Pulflich’s photometer, and the definite conditions for the determination of tin were determined. Effects of other ions were also examined and Al, As, Be, Ca, Cd, Co, Mg, Mn and Ni had no effect on this reaction, but Fe, Sb, Cr, Ag, Hg, W, Mo, V and Ti had some.View full abstractDownload PDF (450K) -
Hidehiro Gotô, Yachiyo Kakita1953 Volume 17 Issue 5 Pages 223-225
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStudies were made at first on the separation of tin in iron and steel. The separation of small amount of tin in a sample was difficult by the usual separation method by hydrogen sulfide, therefore the separation of tin by coprecipitation with manganese dioxide was tried. The conditions of precipitation were decided and the analytical procedures of tin in iron and steel were proposed as follows. Dissolve the sample with nitric acid, dilute with water, and add the manganese sulfate solution. Then add the potassium permanganate solution to the boiling solution and, thus precipitate manganese dioxide. Filter and wash the precipitate, dissolve it with hydrochloric acid and reduce it by aluminium in a stream of carbon dioxide. The colour is developed by adding the cacotheline solution and the determination of tin is carried out by measuring the colour density with Pulflich’s photometer. The time required for this analysis was about 1.5∼2 hours.View full abstractDownload PDF (436K) -
Naokatu Tuda, Kazuo Sonobe1953 Volume 17 Issue 5 Pages 226-230
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo obtain a gong having only one natural frequency for use for telephone, we studied the directional properties of the natural frequency of gongs of 65/35 and 60/40 brass, as well as their directional property in case they are made by deep drawing, with the following results:
1. Generally speaking, the natural frequencies in 0° direction (the direction, in which the material brass plate is rolled) and in 90° direction (the direction at right angles with 0° direction) of a gong are one and the same; and its natural frequency in 45° direction always is constant. But those in 0° and 90° directions and that in 45° direction are not the same.
2. We succeeded in making a gong having no directional property of its natural frequency from 65/35 drass, but failed in so doing from 60/40 drass.
3. We ascertained that there is no direct relationship between a change in the properties in 0° and 45° directions due to the ratio of the thickness of cold-rolled material brass plate and temperature, at which it is annealed, and a change in these properties due to drawing.
4. The conditions most suitable for the manufacture of a brass gong having no directional property of its natural frequency are as follows: 3& (1) Composition: & 65/35 Brass
& (2) Ratio of cold-rolling reduction of thickness: & 30%
& (3) Annealing temperature: & 400 ∼500°View full abstractDownload PDF (836K) -
K. Iwase, T. Sano, J. Matsuoka, M. Kyotani1953 Volume 17 Issue 5 Pages 230-235
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo improve the mechanical properties of metals, a new method named “KRK Process” or “Strain Tempering” has been proposed. The method consists in subjecting the metal to simultaneous action of heat and mechanical force, the latter being tension, compression or torsion according to the situation. During the process, the metal undergoes a more or less permanent deformation and consequently the duration of the process is restricted to a few seconds or minutes according to the temperature in order not to deform the metal too much. The present papers deal with results of the cases in which metals are subjected to tensional force at ca. 100∼600°C. The specimens used in the present experiments are nickel and high carbon steel wires, cold-drawn or heat-treated. The results obtained are as follows. The tensile strength increases slightly and the yield strength prominently by the process. The elongation and the torsion value also increase moderately. The properties of metals treated by KRK Process depend upon (i) the magnitude of force, (ii) the temperature and (iii) duration of the process. By properly choosing these factors, the yield strength increases by 100% or more. The straightness of the wire thus treated is considered to be one of the merits of the process.View full abstractDownload PDF (911K) -
J. Matsuoka1953 Volume 17 Issue 5 Pages 235-239
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAs has been reported in the foregoing papers, the steel wire subjected to patenting or cold worked remarkably increases its strength by K.R.K. Process. The present paper deals with the effectiveness of the process when it is applied to a wire, patented and then 86.7% reduced in 10 steps by ordinary drawing. Results obtained are as follows. The increase of strength of wire by KRK process depends upon the reduction percentage of the wire after patenting. As this percentage increases by successive drawing, the elevation of strength of wire after the treatment increases also. If KRK process is successively applied to the wire after every drawing, the elevation of strength in each time diminishes as the number of application of the process increases, and consequently the difference of strength between that of the wire thus treated and that of the wire reduced without the treatment increases at first and then decreases. Therefore the effective application of the process to the drawing of the patented wire is to apply the process successively in the first or last few steps of the reduction.View full abstractDownload PDF (882K) -
Waichi Ôta1953 Volume 17 Issue 5 Pages 240-243
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen hard materials as high carbon chromium steel are rolled to bar at high temperature, it occurs fraquently that cracks appear at the centers of both the free sides of the bar which don’t come in contact with the roll surfaces. Grinding cracks are generated in the same sites when both the sides are grinded, and sites quenching cracks appear in the same way when quenched. The author concidered that some relations exist between the three cases and carried out some experiments whose results are as follows:
(1) From a microscopic study it is recognized that fiber structure is equally divided in two on the center line adjacent to the free sides and concentrated toward both corners, so severe tension operates on the free side when rolled, which suggests the cause of cracks. (2) It is clarified that severe tensile stress remains in region adjacent to the surface contacting with the rolls, while compression operates in the inner region and remains adjacent to the free sides. (3) When any region with different residual stress is partially and suddenly cut off by grinding, so the balance of stress is broken on the center line on which the stresses are symmetrical and then grinding cracks follows. (4) Since transformation stress due to quenching has the same tendency as residual stress due to rolling, so the latter is superposed by the former at quenching and the crack may be generated.View full abstractDownload PDF (843K) -
Susumu Oki, Ren Obata1953 Volume 17 Issue 5 Pages 243-246
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the 1st report of this paper, there were described the distinctive features of the brittle fracture of this kind, and the influences of heat treatments on it, especially of coolings processes after the solidification. Thus it became evident that the embrittlement is caused by the precipitation of some material on the grain boundaries of primary austenite, when some particular part of a large steel casting cools in such an unusual manner as described in that report.
Later, the influence of chemical composition has been studied and aluminium and nitrogen are found to be the most important elements that increase the tendency of this embrittlement. After all, this kind of brittle fracture is considered to be much the same with what is called “rockcandy fracture”. Lorig showed with considerable evidence that this kind of fracture is due to precipitation of aluminium nitrides. Results of the anthors’ study on the test blocks attached to the bosses of driving wheel casting show that steel containing nitrogen more than 0.01% with aluminium more than 0.08% very often reveals the brittle fracture when it is broken by the tension test.
Means of prevention are discussed, and addition of small amount (0.5%) of titanium is found to be sufficient for the complete recovery of ductility.View full abstractDownload PDF (658K) -
Takashi Ikeno1953 Volume 17 Issue 5 Pages 246-251
Published: 1953
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of Fe or Si upon casting cracks of aluminium ingots were investigated by measuring shrinkages or cracks which were found at casting into a particular metal mould (See Fig. 1). Results obtained are as follows: (1) The higher the casting temperature, the larger the shrinkage, and so the casting at higher temperature promotes the opportunity for cracks. (2) According to the casting temperature or the purity of Al used, there is a proper range for the mould temperature. (3) By the addition of Fe, up to 0.7% the shrinkage decreases 0.7% and the addition of Fe protects ingots from casting cracks, and yet does not affect upon the intercrystalline brittleness of Al. (4) By the addition of Si, up to 0.6∼0.7%, the shrinkage increases but addition over that percentage it decreases the shrinkage. Furthermore, the intercrystalline brittleness increases remarkablly by the addition of Si. (5) Cracks which were found in such cases as hindrance of free contraction, become finer by slow cooling but langer by the rapid cooling, and also the higher the purity of Al, the finer they become generally.View full abstractDownload PDF (910K)
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