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Volume 21, Issue 245
Displaying 1-6 of 6 articles from this issue
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[in Japanese]1955 Volume 21 Issue 245 Pages 287-293
Published: July 05, 1955
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (1451K) -
Kiyokazu OGAWA1955 Volume 21 Issue 245 Pages 294-298
Published: July 05, 1955
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSWearing mechanism of the steel hardened by various types of H. F. generators was studied.The results we obtained were as follows ;
1) Wear of as-quenched steel was reduced by using higher frequency. Moreover the steel having sorbitic structure before H. F. hardening was superior in resistability to the steel of pearlitic structure.
2) Owing to the shorter hardening time, working stress was retained in the steel hardened.and stress caused by quenching being extremely large, they acted negatively to the wear-resistance.
3) Tempering at 150°C200°C after quenching reduced the amount of wear. By doing this, metallic wear became almost independent of the frequency and the metallic structure before quenching.View full abstractDownload PDF (1070K) -
Masahisa MATSUNAGA1955 Volume 21 Issue 245 Pages 299-303
Published: July 05, 1955
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIt was reported in the previous paper that the surface layer had been proved to have high electrical resistance if it is free from breakdown and coherer effect at the oxide film (Rev. Sci. Insts. 25, 1954, 1221). In general, the conditions to obtain high resistance are as follows : (1) The surface is smooth, (2) The electrical conductivity of the oxide is low, (3) The film is considerably thick, (4) The oxide film and the underlying metal are amorphous, (5) The hardness of both metal and oxide are high. The paper describes further experiments. The circuit is shown in figure 2, contact part is bonded graphite with round tip (r=2.5mm), the load on graphite is 110 g., and voltage used is 20 mV. The electrical contact resistance are. 1100 kΩ, in the case of steel (Fig. 3) or specimen plated with chromium when they are finely finished by mechanical methods. On the contrary, the values for copper under the same conditions are smaller than 2Ω. It is found by electron diffraction that the high resistance of the finished surface of the specimen plated with chromium is due to its oxide film.
The contact resistance of an aluminum surface mechanically finished is not high (usually smaller than 8 Ω). The resistance values of the surface, however, becomes rather high as shown in the last column of the figure 3 when it is elaborately polished. The electron micrograph of the film detached from the surface is shown in figure 5, and it shows embedding of abrasives and other materials under the aluminum surface. The high resistance of aluminum surfaces are attributed to the complexity of the mechanically finished surface.View full abstractDownload PDF (1265K) -
Analysis of Tool Life of G Series Carbide Tools (for Cast Irons) (Part.I)Hidehiko TAKEYAMA1955 Volume 21 Issue 245 Pages 304-308
Published: July 05, 1955
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThe conventional analysis through tool life curves, the relationships between cutring speed and life, is not sufficient to investigate the characteristics of carbide tools.
After a great many tool life tests, it has been found out that many interesting characteristics can be detected by plotting the relationship between flank wear and cutting time on log-log paper. The relatiohship thus obtained consists of two straight lines and the critical wear which connects these lines. The slope of each line, its level, the critical wear and so on have their proper meanings and affect the tool life in their particular manners.
In this report, such a new type of analysis has been demonstrated in the case where FC27 (a high class cast iron) was machined with G seties carbide tools manufactured by five different makers.View full abstractDownload PDF (964K) -
Wear Properties of 60 : 40 AlloysFusao HAYAMA1955 Volume 21 Issue 245 Pages 309-313
Published: July 05, 1955
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe wear loss for 60 : 40 brass plate sliding on the steel shaft has been measured. The test apparatus is of such a type that the edge of brass plate finished straight may be loaded on the rotating steel shaft. Therefore the contact pressure decreases gradually with the wear of the sample, but there will be no objection to the fact that the wear loss coincide with the wear by the instantaneous pressure.
The wear loss is maximum at the speed of about 2cm/s, and decreases with increasing speed.The alloys containing much Pb wear to a high degree, but those reduced highly by rolling, wear to a low degree.View full abstractDownload PDF (1044K) -
1955 Volume 21 Issue 245 Pages 322-324
Published: July 05, 1955
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (653K)
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