材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
49 巻 , 11 号
選択された号の論文の13件中1~13を表示しています
  • 諸石 大司, 富士川 尚男, 樽谷 芳男
    2000 年 49 巻 11 号 p. 1171-1178
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 宮本 博之, 森川 孝之, 御牧 拓郎, 橋本 敏
    2000 年 49 巻 11 号 p. 1179-1184
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Corrosion fatigue of pure copper single crystals having a single activated slip system in aquious 1M NaNO2 solutions was investigated by focusing on the effect of anodic potential and role of persistent slip bands (PSBs) on the crack nucleation. The number of cycles to fracture is lowest under 100mV vs. Ag/AgCl followed by those under 0 and 250mV vs. Ag/AgCl. Potential of 100mV corresponds to where sensitivity of the transgranular stress corrosion cracking (TGSCC) in pure copper was reported to be highest under monotonic tensile deformation in a slow strain rate test. A number of cracks were observed at PSBs under 100mV vs. Ag/AgC, and plane of the cracks corresponds to {110} plane normal to applied tensile axis. Crystallographic features of the cracks formed under 100mV vs. Ag/AgCl were similar to those of TGSCC of pure copper single crystals deformed monotonically. Anodic current increased when the Bauschinger energy parameter βe showed a peak, suggesting that cracks formed along the PSBs. It is suggested that the cracks formed by the same mechanism of TGSCC in pure copper, and PSBs play an important role in nucleation of cracks under cyclic deformation.
  • 熊田 誠, 小渕 茂寿
    2000 年 49 巻 11 号 p. 1185-1192
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Corrosion tests of mild steel and welded mild steel have been coducted to study the corrosion protection effect in the simulated inert gas environment of crude oil tankers. Morever, causes of corrosion cracking failures in inert gas environment of brass tubes for heating heavy crude oil have been invesigated. The results are as follows:
    (1) The corrosion protection effects of mild steel in N2 gas containing O2 become 47% under O2/N2=0.1, 74% under O2/N2=0.04, 88% under O2/N2=0.01. The corrosion protection effect of 74% at O2/N2=0.04 shows that O2 concentration is not a corrosion factor.
    (2) The corrosion protection effect in inert gas environment of oil tanker becomes minus 13.5% to that in air.
    (3) The reaction of HSO3-+5H++4e=S+3H2O which occurs in low pH H2SO3 solution accelerates corrosion of mild steels together with O2 and H+ as cathodic reaction.
    (4) Since the inert gas environment containing 250ppm SO2 causes the same corrosion rate as that in air, SO2 gas effects severely corrosion in the actual environment. Accordingly, control of SO2 gas is important for corrosion protection under inert gas system in oil tanks and ballast tanks.
    (5) Corrosion failures of brass tubes for heating crude oil seem to be caused due to sulfide stress corrosion cracking and sulfide corrosion fatigue.
  • 茂 博雄, 中山 武典, 池田 貢基, L.F. VEGA, E.L. COLVIN
    2000 年 49 巻 11 号 p. 1193-1199
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Correlation between laboratory tests and field tests for filiform corrosion of painted aluminum alloy sheets for automobile was investigated by conducting 6 kinds of laboratory tests with different pH, dry-wet condition, etc., and 2 sites of outdoor exposure tests, and vehicle test. It was found that susceptibility to filiform corrosion in the laboratory tests increased with the decrease of pH and/or the increase of repetition rate of wet/dry cycle, and that correlation between outdoor exposure tests and vehicle test was low. In conclusion, the laboratory tests with relatively low wet ratio (70%) correlated well with the outdoor exposure tests, and the tests with relatively high wet ratio (95%) correlated with the vehicle test.
  • 松田 宏康, 吉田 賢, 桂 義人
    2000 年 49 巻 11 号 p. 1200-1206
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    To prevent corrosion by MIC (Microbiologically Influenced Corrosion) of the heat exchanger's carbon steel tubes in Mitsui Chemicals Osaka Works (MCI Osaka), we improved the cooling water recirculating system. Furthermore we have studied the ability of several kinds of inhibitors used in our water cooling system.
    To reduce MIC potential, we have changed the sterilizing method from the intermittent addition of bactericide (NaClO) to the continuous addition. As a result, life of the heat exchangers were prolonged more than two times. Additionally, we have studied the ion selective property of synthetic iron rust membranes (β-FeOOH) adsorbed the inhibitor, such as OP (Ortho Phosphoric acid), PBTC (2-Phosphno Butane-1, 2, 4-TriCarboxylic acid), HEDP (Hydorxy Ethilidene-1, 1-Di Phosphonic acid), PAA (Poly Acrylic Acid) and so on.
    Cation selectivity was increased in the order: OP<PAA<HEDP<PBTC. From this fact, it was found that HEDP and PBTC is more effective for corrosion prevention compared to PAA and OP. Iron rust adsorbed the inhibitors containing HEDP or PBTC has ability of preventing corrosive anion like chloride ion from penetrating it into metal surface.
  • 2000 年 49 巻 11 号 p. 1207-1210
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 皆木 卓士, 塩野 剛司, 有谷 博文, 西田 俊彦
    2000 年 49 巻 11 号 p. 1211-1216
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Forsterite (Mg2SiO4) precursor was synthesized from heterogeneous alkoxide solution containing MgO powder (mean particle size: 10nm). In order to examine thermal behavior of the precursor, DTA was carried out. The precursor was calcined at temperatures before and after each exothermic and endothermic reaction. The calcined powders were examined by XRD analysis and FT-IR spectroscopy to clarify the reactions. It was found that C2H5OH adsorbed on the surface of the powder evaporates at 82°C, Mg(OH)2 decomposes at 390°C and that forsterite phase is formed at 796°C. The changes in near-surface crystal structure involving these reactions were evaluated by Si and Mg K-edge XANES spectroscopy. The forsterite precursor was found to have a metastable structure before crystallizing as forsterite crystal, resulting from the dehydration around 400°C. The phase was identified as amorphous and the electronic structure was close to Mg2Si3O8.
  • 木村 英彦, 秋庭 義明, 田中 啓介, 安達 修平, 滕 海君
    2000 年 49 巻 11 号 p. 1217-1223
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Smooth and notched specimens of reactive-sintered Ti-45at%Al-1.6at%Mn intermetallic compound with lamellar and equiaxed γ microstructures were fatigued under cyclic axial tension compression at room temperature. The effect of microstructures on the crack propagation behavior was investigated in comparison with cast Ti-47.2at%Al with larger grain size.
    Fatigue crack paths were tortuous in the lamellar microstructure in contrast to the straight crack paths in the equiaxed γ microstructure. In comparison with cast TiAl, reactive-sintered TiAl exhibited higher crack propagation rates when compared at the same stress intensity range. The values of stress intensity range at threshold were greater in cast TiAl. Those threshold values had a tendency to increase with the roughness of the fracture surface. The rate of increase in crack opening stress intensity factor at threshold with non-propagating crack length was smaller than that of cast TiAl. Predicted fatigue limits for crack initiation and propagation based on the fatigue-crackgrowth resistance-curve method were in agreement with the experimental results. The fatigue limits of notched specimens were smaller than those of cast TiAl in spite of the superior mechanical properties of reactive-sintered TiAl.
  • 山内 雅文, 中馬 康晴, 大谷 知未, 高橋 由紀夫
    2000 年 49 巻 11 号 p. 1224-1229
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    High temperature low-cycle fatigue tests were conducted by using a miniature specimen with diameter of 2mm and gage length of 3mm in order to investigate a detailed distribution of low-cycle fatigue properties in a welded joint of 316FR stainless steel. First, a high temperature low cycle fatigue testing procedure by miniature specimens was established. Five kinds of specimen were taken from the 316FR stainless steel welded joint of 50mm thick plate; one from the base metal, two from the heat affected zone with different hardness, and two from the weld metal in longitudinal and tangential directions. Low-cycle fatigue tests were carried out at 550°C at the strain rate of 0.1%/sec in air. Detailed low-cycle fatigue properties, such as fatigue strength, cyclic hardening/softening behavior and cyclic stressstrain curve, of the 316FR stainless steel welded joint were clarified.
  • 高橋 昌男, 橋本 泰宏, 吉川 信一, 小林 光
    2000 年 49 巻 11 号 p. 1230-1234
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    Several rare earth doped lanthanum dioxymonocyanamide phosphors have been prepared by calcining mixture of La2O3 and rare-earth oxide powders under flowing ammonia gas in the existence of carbon. Incorporated rare earth ions worked as a luminescence center. Colors of the luminescence of these phosphors irradiated by the monochromatized x-ray of 9keV were pale blue, reddish purple, red and green for Pr, Sm, Eu and Tb, respectively. For optical luminescence spectra measured for (La1-xEux)2O2CN2 at room temperature, the relation between the fluorescence intensity and Eu content, x was discussed with the solid solution limit of Eu to La2O2CN2, estimated by the XRD and XANES analyses.
  • 石神 逸男, 横山 雄二郎, 三浦 健一, 浦谷 文博, 星野 英光
    2000 年 49 巻 11 号 p. 1235-1241
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    A low carbon steel, S15CK, was carburized at the temperatures of 1113 to 1313K for times up to 20.571ks in a propane atmosphere at 2.67kPa and thereafter diffused below 0.133Pa for times ranging from 0 to 18.9ks at the same temperature where carburizing was done. Carbon profiles were determined by a succession of grindings and emission spectrochemical analyses of the ground surfaces. The uptake amount of carbon by a thin specimen was measured by infrared absorptiometric method after combustion in the current of oxygen. Carbon flux was evaluated from dependence of the amount on carburizing time. A mathematical model is proposed to describe carburizing behaviors. Comparison between the calculated and the experimental profiles revealed that the model was able to represent the carburizing behaviors precisely. Both experimental and calculated results verified that treatments at the same ratio of carburizing time to diffusing time give the same surface concentration of carbon. This fact is very useful to find out the optimum condition in vacuum carburizing.
  • 単サイクルの水素吸蔵-放出プロセスにおける変形挙動
    丁 泳鑵, 末廣 秀樹, 酒井 譲
    2000 年 49 巻 11 号 p. 1242-1248
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
    By using the electrolytic method, thin plate Palladium specimens are loaded with hydrogen to examine the relation between the lattice expansion and the hydrogen absorption rate, and the relation between the lattice expansion and bulk deformation of specimens at each hydrogen absorbing rate on one hydrogen absorption-desorption cycle. The behavior of the lattice expansion on the hydrogen absorbing rate can be obtained by X-ray diffraction analyses. It is noted that the lattice size increases quickly with increasing hydrogen absorbing rate (H/Pd) up to 0.2, however, above the rate the lattice size keeps constant value. The expansion rate of the Pd plate specimen agree well with the lattice expansion rate in longitudinal and width direction of the specimens, though in thickness direction the expansion rate is about 5 times lager than other directions.
  • 4. 廃棄物の処理処分・廃棄物地盤の跡地利用と地盤改良技術
    小野 諭
    2000 年 49 巻 11 号 p. 1249-1254
    発行日: 2000/11/15
    公開日: 2009/06/03
    ジャーナル フリー
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