巻号一覧
40 巻, 2 号
選択された号の論文の7件中1～7を表示しています
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木谷 聰生1971 年 40 巻 2 号 p. 83-98
発行日: 1971/02/25
公開日: 2011/08/05
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有川 正康1971 年 40 巻 2 号 p. 98-111
発行日: 1971/02/25
公開日: 2011/08/05
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手塚 敬三1971 年 40 巻 2 号 p. 111-121
発行日: 1971/02/25
公開日: 2011/08/05
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山崎 康久1971 年 40 巻 2 号 p. 121-125
発行日: 1971/02/25
公開日: 2011/08/05
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大西 巌, 岡本 郁男, 森沢 潤一郎, 長井 正行1971 年 40 巻 2 号 p. 126-136
発行日: 1971/02/25
公開日: 2011/08/05
ジャーナル フリーAuthors have reported that both H+ and Cl- ions in an aqueous solution of HCl acted well as flux for the spreading of solder on copper base metal. However, the flux action of the individual ion cannot be made clear, because that solution includes simultaneously these ions. So, in the present paper, the aqueous solution of H2SO4 was selected as flux not containing Cl- ions, and particular aqueous solutions including Cl-ions at various concentrations were prepared by adding NaCl to the aqueous solution of H2SO4, and in order to distinguish the electrochemical flux action of each ion, the corrosion potentials of base metal and solder were measured in these solutions arid also spreading tests wre made by the same methods described in the previous report.
In.addition, external cathodic polarization. curves of base metal and external anodic polarization curves of the solder were plotted to investigate whether there was a relation between the spreading of solder and the electrode reaction of a galvanic cell formed instantaneously in contact with the base metal and solder in these aqueous solutions.
The results obtained from these investigations are summarized as follows:
1) When the concentration of H+, ions in.the particular aqueous solutions was kept constant, the spreading of solder did not increase, appreciably with an increasing concentration of Cl- ions in these solutions. But a significant increasing phenomenon of the spreading occurred at a certain critical concentration of Cl- ion in both solutions of pH's about 2.5 and 3.0.
2) A correlation between logarithm of the critical Cl- ion activity and pH of the aqueous solution is shown by following eq.
log acl-=-4.65+pH (1.0<pH<3.0)
As this experimental eq. approximates to a theoretical eq. (10), the flux action of Cl- ion for the base metal may be expressed by the meaning of eqs. (10) and (13).
3) When the corrosion potential of the galvanic cell had a higher value than the break potential of the cathodic polarization curve, the spreading of solder did not occur because the formation of H2O2 or, H2O on cathode (that is base metal) decreased H+ ion concentration. in the aqueous solution. It is concluded that the higher the concentration of H+ ions in flux solution, the better the spreading of solder becomes.抄録全体を表示PDF形式でダウンロード (771K) -
アプセット現象の研究安藤 弘平, 仲田 周次, 福井 一郎1971 年 40 巻 2 号 p. 137-151
発行日: 1971/02/25
公開日: 2011/08/05
ジャーナル フリーFundamental characteristics in upsetting process of flash welding are studied by metallurgical and mechanical methods without regard to flashing process. The results obtained are as follows.
Mechanical strength of third-lip welded joint is proved to be good regardless of presence or absence of flashing just before upsetting process. For another shaped weld with no third-lip, however, specimen is greatly affected by presence of flashing, and fractured at weld line when the flashing is absent just before the upsetting process.
"Third-lip" shaped weld is obtained at high upset current and adequate current duration and upset force, for the molten metal layer is formed by Joule's heating in early stage of upsetting process, and "thirdlip" shaped weld is produced as the result of the molten metal being expelled by the upset pressure. White metal layer formed in weld line is practically composed of ferrite as the result of de-carburizing.
The molten metal layer plays a fundamental role to disperse the oxide inclusion produced in flashing process.
If the weld is solidified and cooled under low pressure and small deformation in upsetting process, a columlar structure in the molten layer zone and a Widmanstatten structure in heat affected zone are observed and so mechanical properties of welded joint become inferior, especially in affected zone.
Accordingly, the upsetting action is to produce the molten metal in early stage and then to solidfy and cool the molten metal and heat affected zone under adequate deformation by high pressure and to improve the mechanical properties of the weld metal.抄録全体を表示PDF形式でダウンロード (13829K) -
益本 功, 江原 隆一郎1971 年 40 巻 2 号 p. 152-160
発行日: 1971/02/25
公開日: 2011/08/05
ジャーナル フリーIt was clarified by the previous reports that crack propagation rate was predominantly affected by oxygen and/or humidity in atmospheres.
Then, plastically deformed zone at the tip of fatigue crack was observed by an optical and electron microscopies, in order to know why does the crack propagation rate change with atmospheres.
Crack propagation angle of fatigue tested specimen was also measured. A larger crack propagation angle will mean more plastically deformed cracking.
Generally speaking, the angle of fatigue tested specimen in the atmosphere without oxygen and/or humidity was larger than that in air. Significant difference of fracture surfaces were observed by electron microfractographies depending on the fatigue tested atmospheres. Some differences of hardness and slip line density at the tip of fatigue crack in different atmospheres were also observed. It can be concluded that crack in atmosphere without oxygen and/or humidity propagate with more plastic deformation than that in air.抄録全体を表示PDF形式でダウンロード (9173K)
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