圧力技術
Online ISSN : 1347-9598
Print ISSN : 0387-0154
ISSN-L : 0387-0154
42 巻, 2 号
選択された号の論文の5件中1~5を表示しています
論文
  • 臼井 俊央, 齊藤 文一, 田村 英樹, 橋口 拓泰
    2004 年 42 巻 2 号 p. 60-68
    発行日: 2004年
    公開日: 2004/08/31
    ジャーナル フリー
    Ballistic impact tests were conducted on intermediate purity titanium plate and Ti-6pctAl-4pctV-ELI alloy plate and newly developed Ti-Fe-O-N alloy plate using ogive-shaped projectile with 7. 62mm diameter to study relation between the fracture mechanisms and adiabatic shear band formation The plugging process was dominated by adiabatic shear deformation in localized bands.
    Selected data and optical micrographs relating to the adiabatic shear band formation, the variation of depth of penetration and ballistic limit velocity were presented.
    The fracture mechanisms associated with the shear localization and fracture process changed from bulging failure to plugging failure by a shocked pressure increase.
    The results showed the differences of the fracture mechanisms between two high strength titanium alloys are responsible for significant differences in the elongation of their mechanical property and in the evolution of shear band patterns
    It also showed evidence of the long shear band connected from the shocked surface to the bulging region was found in all target plates, but evidence of the long cracks connected did not be found in all target plates at impact velocity just near below each ballistic limits
  • 三村 宏, 田川 哲哉, 孕石 泰丈, 岩崎 正美, 阿部 英嗣, 宮田 隆司
    2004 年 42 巻 2 号 p. 69-75
    発行日: 2004年
    公開日: 2004/08/31
    ジャーナル フリー
    The local fracture stress, such as σF in the Knott model or σu in the Beremin model, has been thought to be independent of temperature, which has been explained by the Griffith equation with constant surface energy γeff.
    An application of the mod:f:ed Beremin model gives a more plausible method to correlate the local fracture stress with γeff. It is shown that γeff increases with raise in temperature.
  • 松原 雅昭, 佐々木 哲也, 伊澤 悟
    2004 年 42 巻 2 号 p. 76-80
    発行日: 2004年
    公開日: 2004/08/31
    ジャーナル フリー
    A simplified procedure can calculate collapse stresses on a flawed rectangular beam for combined tension and bending. The results obtained are as follows:
    (1) The method enables us to calculate the collapse stresses for any flaw size and any combination of tension and bending.
    (2) The method leads to an allowable flaw size of about one-tenth the beam width.
    (3) The method gives the evaluation of safe side for the experimental result in the case that the defect size⁄beam width ratio is 0. 6.
  • -石油タンク底板の防食技術の開発 第五報-
    加藤 謙治, 児嶋 一浩, 加藤 忠一, 石本 裕保, 屋敷 孝志
    2004 年 42 巻 2 号 p. 81-87
    発行日: 2004年
    公開日: 2004/08/31
    ジャーナル フリー
    Large efficiency of Zn sprayed steel plate for enhancement corrosion lifetime has been investigated in previous paper. To apply Zn sprayed steel to bottom plate of industrial oil tanks, weld work being essential for building affects metallic condition and corrosion preventive property of Zn layer largely. To avoid detrimental effect of welding, numeric heat input analysis and corrosion test of heat affected zone on Zn sprayed layer was carried out to find optimum utilizing conditions in this study.
    As a result, it is found that the surface temperature goes above melting point of zinc easily resulting oxidization of outer surface and formation of Fe-Zn alloy layer that are detrimental corrosion. And it is also found that limiting heat input of welding to 0. 6kJ⁄mm at filet welding with 9. 0mm thickness enables to minimize the damage to the Zn sprayed surface. Based on this finding, corrosion test of Zn sprayed plate with weld, with which heat input control at welding was carried out. Weld sample with the heat input control has shown good corrosion resistance.
    Based on findings above, building of bottom plate for 30, 000kl industrial oil storage tank utilizing Zn sprayed steel plate has been completed successfully.
  • -石油タンク底板の防食技術の開発 第六報-
    加藤 謙治, 加藤 忠一, 石本 裕保, 屋敷 孝志
    2004 年 42 巻 2 号 p. 88-94
    発行日: 2004年
    公開日: 2004/08/31
    ジャーナル フリー
    Corrosion condition of Zn splayed plate adapted to annular plate of industrial oil storage tank for ten years is investigated. As a result, not only the efficiency of Zn sprayed plate as a corrosion prevention measure but also validity of corrosion lifetime estimation method proposed in previous reports is confirmed. Main results are as follows.
    Base steel with Zn sprayed layer of 300∼400μm thickness served for annular plate of industrial oil storage tank in field for ten years is confirmed to be free from corrosion problem. No reduction in thickness of base metal is observed. Specimens with Zn splayed layer of 480∼610μm thickness have also been buried in berm of oil storage tank for ten years. Little rust points are observed on them, but the corrosion rate is negligible small less than 0. 021mm⁄y. Hence, the efficiency of Zn sprayed steel as corrosion prevention method is proved in the field.
    Moreover, corrosion conditions of these specimens are estimated by the newly proposed method being based on extreme statistics analysis and corrosion test results in laboratory. Estimated results are in good agreement with observed corrosion condition quantitatively.
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