著者

明日香 壽川 山本 政一郎 朝山 慎一郎

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.74, no.1, pp.61-63, 2010

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&nbsp;&nbsp;Endo <i>et al</i>. says that the sea level will be lower due to the ice in the polar region, and refers to the IPCC (Inter-governmental Panel on Climate Change) assessment reports as if these reports would have supported the notion. The referred sections of IPCC reports, however, describe the effects of &ldquo;polar ice sheets&rdquo; of Antarctica and Greenland combined, and not &ldquo;ice in the polar region&rdquo; as Endo <i>et al</i>. says. The misinterpretations of these terms also lead to their unfounded and untenable criticism on the &ldquo;White Paper on the Environment&rdquo; published by the Ministry of the Environment, Japan.<br>

著者

遠藤 小太郎 吉田 真悟 中嶋 貴裕 行本 正雄 武田 邦彦

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.70, no.5, pp.420-426, 2006

被引用文献数

1

---

&nbsp;&nbsp;The respective awareness of the Intergovernmental Panel on Climate Change (IPCC), the Japanese government, media and citizens about the change of sea level at some future date due to climate change was surveyed and analyzed. Three official reports from the IPCC, the white paper on the Quality of the Environment in Japan from the government, the articles in the Asahi Shimbun newspaper from about the past 20 years, and the questionnaires by the Japanese and local governments conducted towards citizens were used. The results of this investigation were that the IPCC concluded in their past three reports that the sea level was estimated to be lower because of ice in the polar regions due to climate change, the Japanese government did not describe this point clearly, the newspaper drew the opposite conclusion from the IPCC and the understanding of citizens was that the change in climate caused the sea level to rise. These differences were due to the lack of or misunderstanding of scientific knowledge such as Archimedes's Principle and the migration of fluid materials, and to the psychological trend of human beings. It is necessary for the government and media to clearly explain and announce these scientific facts in a modern society which maintains a close relationship to science.<br>

著者

田中 眞奈子 北田 正弘

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.74, no.4, pp.250-257, 2010 (Released:2010-04-01)

参考文献数

16

被引用文献数

7 5

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The composition and microstructure of nonmetallic inclusions of a Japanese matchlock gun, called Hinawa-ju in Japanese, fabricated in the Edo period have been investigated. The purpose of this work is to study the composition and microstructure of nonmetallic inclusions of the barrel and to obtain modern materials-science data of the raw materials of the Japanese matchlock gun. Test pieces are cut from the center and the male screw of the barrel. Nonmetallic inclusions of the barrel are observed using an optical microscope and scanning electron microscope (SEM). The small-area concentration of a nonmetallic inclusion is obtained by electron dispersive X-ray analysis (EDS). The electron backscattering pattern (EBSP) is analyzed using an ultrahigh-resolution scanning electron microscope. Fe, Si, Al, Ca, K, Mg, P, Na and Ti are detected from nonmetallic inclusions of the center of the barrel. As Ti is detected from many parts of the nonmetallic inclusions, iron sand is inferred to have been used as the raw iron material of the barrel. Nonmetallic inclusions of the center of the barrel are classified into two groups. One is a plural phase and is consisted of FeO (wustite), Fe-Si-O grains, multi-element grains and glass-rich matrix oxide. The other type is a single phase of aluminum silicate glass. Fe, Si, Al, Ti, Ca, Mg, K, Na, P, Mn and S are detected from nonmetallic inclusions of the male screw of the barrel. As Ti is detected from many parts of the nonmetallic inclusions, iron sand is again thought to have been used as the raw iron material of the male screw. Nonmetallic inclusions of the male screw are of the plural phase and consist of Fe-Ti-O grains, aluminum silicate oxide and aluminum silicate glass matrix.

著者

田中 眞奈子 北田 正弘

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.76, no.8, pp.489-495, 2012 (Released:2012-08-01)

参考文献数

15

被引用文献数

2 1

---

The microstructure and mechanical properties of the steel barrel of a Japanese matchlock gun fabricated by the gunsmith Kunitomo Tokudayuu in the Edo Genroku period have been investigated. The purpose of this work is to obtain modern materials-science data for a Japanese matchlock gun fabricated by a noted Kunitomo gunsmith and to study the manufacturing technique of the steel barrel. Specimens are cut from the center, the muzzle, and the screw of the barrel. The carbon concentration is determined by chemical analysis. The microstructure and nonmetallic inclusions of the specimens are observed with an optical microscope and a scanning electron microscope (SEM). To evaluate the hardness, Vickers hardness (Hv) is used. The inner structure of the screw is observed by X-ray radiography. The carbon concentration is 0.007 mass% in the center of the barrel and 0.07-0.3 mass% in the muzzle. The distribution of nonmetallic inclusions in the center of the barrel indicates that the barrel was fabricated by joining two long edges of a steel sheet, a technique that is called Udonbari (seamed steel pipe in Japanese). The muzzle was reinforced with steel having a higher carbon content than that of the center of the barrel by rolling the steel over the Udonbari barrel. The female screw of the barrel was made of clad steel. Both male and female screws of the barrel were made by a cutting technique.

著者

岡本 正三 田中 良平

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.22, no.4, pp.173-176, 1958

被引用文献数

1

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The deterioration resistance of three marquenching oils (one imported and two home products), were compared by measuring their various physical properties and cooling ability. These measurements were carried out on fresh and deteriorated samples under the exactly same conditions by an electric-resistance heater immersed in each. In the measurement of the cooling ability a carbon tool steel and a bearing steel were used as specimens, and after the marquenching, the depth of hardening in constant size specimens and the critical diameter in variable size specimens were determined. It was found that, among these oils, one of the home products is superior to others in cooling ability and particularly in stability against deterioration.

著者

李 敬鋒 川崎 亮 解 子章 渡辺 龍三

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.55, no.4, pp.466-471, 1991

被引用文献数

1

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A simple test method using small sized specimens is often required for the effective development of ceramic materials. In the present work, the Modified Small Punch (MSP) test was employed for evaluating the thermal shock resistance of Y<SUB>2</SUB>O<SUB>3</SUB>-ZrO<SUB>2</SUB> and SiC ceramics.<BR>The change in strength after quenching from various temperatures was evaluated accurately by the MSP test. The load vs. deflection curves obtained by the MSP test provided more detailed information about the thermal shock by quenching. It has been found that the measured values of the critical temperature difference which indicates the thermal shock resistance of the ceramics are in good agreement with the theoretically calculated values for the materials investigated in the present work. The results show that the combination of water quenching and MSP test is effective for the evaluation of thermal shock resistance of ceramics.

著者

宮内 喜子 江阪 久雄 篠塚 計

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.73, no.9, pp.732-741, 2009 (Released:2009-09-01)

参考文献数

12

被引用文献数

8 11

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Recently, lead-free solders have been used in electronic equipments. Sn-Ag-Cu system is an important alloy for lead-free solders. There have been so many reports for mechanical properties of bonding. It is important to understand the evolution of solidified structure of these alloys, though, such reports are few.    In order to understand the solidification process of Sn-Ag-Cu alloys, Sn-Ag alloys have been used in this study. Three alloys, hypo-eutectic, eutectic, and hyper-eutectic alloys have been prepared. The specimen was quenched during solidification and the solidified structure was interrupted and compared with thermal history.    In the case of hypo-eutectic alloy, the specimen was composed by primary Sn and eutectic. It was found that a small undercooling was necessary for nucleation of eutectic. Such undercooling was not observed in eutectic and hyper-eutectic alloys. This may be interpreted by the difference in the liquid composition when the eutectic solidification starts. In the case of eutectic and hyper-eutectic alloys, the eutectic as well as β-Sn may form at almost the same time of recalescence.    In the case of hyper-eutectic alloy, it was found that a large undercooling was not necessary for nucleation of Ag3Sn, even though it was facetted phase. Since the primary Ag3Sn was surrounded by the halo of β-Sn and eutectic, the Ag3Sn phase may be a site for nucleation of β-Sn and eutectic.

著者

孫 仁俊 中野 博昭 大上 悟 小林 繁夫 福島 久哲 堀田 善治

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.69, no.10, pp.892-898, 2005 (Released:2005-10-20)

参考文献数

13

被引用文献数

12 13

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The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al and Al-Mg alloy was investigated by means of polarization curves in solutions containing 300 ppm of Cl- and by surface analysis. The potentials for pitting corrosion of Al and Al-Mg alloy were evidently shifted to the noble direction by ECAP process, indicating that this process improves resistance to pitting corrosion. SEM observation revealed that the pitting corrosion occurred near the impurity precipitates and the size of impurity precipitated decreased with ECAP process. The time-dependence of corrosion potential and the polarization resistance determined by AC impedance technique suggested that the formation rate of Al oxide films was increased with ECAP process. The improvement in pitting corrosion resistance of Al and Al-Mg by ECAP seems to be attributable to the decrease in the size of impurity precipitates and the increase in the formation rate of Al oxide films.

著者

樋尾 勝也 安達 崇 山田 隆志 土田 豊 中島 浩衛 細井 祐三

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.64, no.12, pp.1148-1155, 2000 (Released:2008-04-24)

参考文献数

35

被引用文献数

1 1

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A study has been made on the effects of Al, Si and Mo on anodic polarization characteristics of Fe-10Cr alloys in 0.05-1.0 kmol·m−3 H2SO4 and NaCl aqueous solutions. Potential decay curves have also been measured in order to evaluate the stability of the passive films formed on Fe-10Cr alloys containing Al, Si and Mo. The analysis of the chemical composition of the passive film has been carried out by AES and XPS.The addition of Mo was very useful to decrease the critical passivation current density of Fe-10Cr alloys which contained Al and Si. The passive current density decreased with addition of 2 mass%Mo to an Fe-10Cr-3Si alloy, while it increased in an Fe-10Cr-3Al alloy. Pitting potential was moved toward the noble direction by the addition of Mo, except for the case of an Fe-10Cr-3Al-3Si-2Mo alloy. It seems that Laves phase (Fe2Mo) was precipitated in this alloy, and Mo-depleted zone was formed locally. The activation time was increased by the addition of Al, Si and Mo to Fe-10Cr alloys. Two step potential decay curves were obtained in Si-containing alloys, and this behavior of the decay curve was shown more clearly in an Fe-10Cr-3Si-2Mo alloy. The results of AES and XPS analysis indicated that Cr and Al concentrated in the passive film of an Fe-10Cr-Al alloy. In the case of an Fe-10Cr-Si alloy, Si concentrated in the surface region of the film and Cr did in the internal region of the film. The confirmation was not possible for the enrichment of Mo in the passive film.

著者

猪子 富久治 安宅 健 木村 節 秋園 幸一 美馬 源次郎 辛島 誠一

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.46, no.7, pp.672-679, 1982

被引用文献数

2 2

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In order to examine effects of the grain boundary on initiation of fatigue cracks, aluminum bicrystals were produced with Bridgman method. They were tested by a bending fatigue testing machine under the constant strain amplitude of 0.18%.<BR>It has been found that conditions necessary for the initiation of fatigue cracks along primary slip bands in the grain boundary affected-regions are as follows:<BR>(1)&emsp;Dislocations parallel to the grain boundary planes are of nearly the screw type.<BR>(2)&emsp;Cross slip on the primary slip systems can be promoted due to incompatibility of elastic and plastic strains at grain boudaries.

著者

貴田 啓子 北田 正弘

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.74, no.3, pp.158-164, 2010 (Released:2010-03-01)

参考文献数

8

被引用文献数

11 7

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The deterioration mechanism of ferric ferrocyanide (Fe4[Fe(CN)6]3·xH2O) which is called Prussian blue, used as a blue pigment in Ukiyo-e printed in late Edo period, has been investigated. The two Ukiyo-e of the same design differ in their degree of deterioration; one print has good color, but the other is seriously discolored. The conditions of their blue areas are compared. The composition of the Ukiyo-e color pigments are analyzed by EDS (Energy Dispersive X-ray Spectroscopy). FT-IR (Fourier Transform infrared Spectrometer) is used to identify the functional group in the chemical compound. Areas of good blue color in the Ukiyo-e contain Fe, which is the main element in ferric ferrocyanide. In the FT-IR spectra, the absorption peak of around 2090 cm-1 corresponding to the CN triplet combination of ferric ferrocyanide (Fe4[Fe(CN)6]3·xH2O) is recognized. The Fe concentration in the faded blue area in the discolored sample is reduced to one-third that in the nondiscolored sample at the same position. The peak corresponding to the CN group has disappeared. A non discolored sample is subjected to accelerated ageing under the condition of high temperature and high humidity (353 K, 65%rh). The peak intensity of reflectivity in the aged sample decreases gradually with ageing.

著者

鶴田 華子 清水 一行 村上 武 鎌田 康寛 渡邉 英雄

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.85, no.6, pp.239-246, 2021-06-01 (Released:2021-05-25)

参考文献数

17

被引用文献数

1

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The plan-view and cross-sectional microstructures of SUS304 steel irradiated by gallium focused-ion beam were investigated using electron backscatter diffraction and energy dispersive X-ray spectroscopy. Structural phase transformation and gallium implantation were confirmed in the region of irradiated austenite grains. The amount of bcc phase and gallium concentration increased with increasing irradiation dose, which suggests that gallium implantation plays an important role as a ferrite stabilizer and also the source of stress effect. Crystallographic orientation relationships between bcc phase and austenite matrix were analyzed by considering the angular deviation between closed-packed planes and closed-packed directions. Differences in transformation behaviors between (001) and (111) austenite grains were discussed from the view-points of fcc-bcc interface structures.

著者

遠藤 小太郎 吉田 真悟 中嶋 貴裕 行本 正雄 武田 邦彦

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.70, no.5, pp.420-426, 2006 (Released:2006-05-21)

参考文献数

30

被引用文献数

1 1

---

The respective awareness of the Intergovernmental Panel on Climate Change (IPCC), the Japanese government, media and citizens about the change of sea level at some future date due to climate change was surveyed and analyzed. Three official reports from the IPCC, the white paper on the Quality of the Environment in Japan from the government, the articles in the Asahi Shimbun newspaper from about the past 20 years, and the questionnaires by the Japanese and local governments conducted towards citizens were used. The results of this investigation were that the IPCC concluded in their past three reports that the sea level was estimated to be lower because of ice in the polar regions due to climate change, the Japanese government did not describe this point clearly, the newspaper drew the opposite conclusion from the IPCC and the understanding of citizens was that the change in climate caused the sea level to rise. These differences were due to the lack of or misunderstanding of scientific knowledge such as Archimedes's Principle and the migration of fluid materials, and to the psychological trend of human beings. It is necessary for the government and media to clearly explain and announce these scientific facts in a modern society which maintains a close relationship to science.

著者

川上 雄士 円城寺 隆志 毛利 茂樹 田中 宏季 高島 和希

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.71, no.2, pp.195-198, 2007

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&nbsp;&nbsp;In this paper, we describe an experimental study of pulsed current sintered binderless tungsten carbide hard metal. The binderless tungsten carbide is expected to be a highly precious mold material used under high temperature and harsh conditions.<br> &nbsp;&nbsp; Low temperature and rapid sintering are achieved by the pulsed current sintering method. The developed material has more than 99% of relative density and Rockwell hardness of 96.5[HR30N] without applying hot isostatic press. Due to its rapid sintering, the material has fine microstructure and fine surface roughness. The polished surface roughness (Ra) is less than 3 nm.<br>

著者

柴田 清 杉山 静一 斎藤 文良 早稲田 嘉夫

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.63, no.7, pp.809-816, 1999 (Released:2008-04-24)

参考文献数

35

被引用文献数

1 1

---

Automobile transportation is one of the predominant sources of air pollution, producing CO2, NOx, and SOx. The weight reduction of automobiles is essential for reducing the environmental burden during their life cycle. High-tension steel, aluminum alloy and resin are candidates for such purpose. However, substituting aluminum for steel is not always beneficial with respect to reducing the burden on the environment, because the energy consumption during aluminum production is considerably greater than that for steel. A generalized equation has been derived to describe the relationship between the driving distance, weight reduction, materials production route, and change in environmental performance. In particular, the effect of the difference of electricity source for aluminum smelting on life cycle CO2, NOx, and SOx, by substituting aluminum for steel in automobile parts, is discussed. The reduction of CO2 emission can be expected for all cases, if 50% of mass reduction is made. On the other hand, aluminum produced by the uncontrolled coal fire power is not capable of reducing NOx emission. It is also suggested that a reduction of SOx emission can only be obtained when using very clean aluminum.

著者

小川 芳樹 久松 敬弘 河村 和孝

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.21, no.10, pp.597-599, 1957 (Released:2008-04-04)

参考文献数

6

被引用文献数

1

---

A method for preparing protective coating on mild steel has been dealt with. The principle lies in that titanium can be deposited on a steel sheet when it is immersed side by side with a titanium sheet or titanium powder in a fused-salt bath consisting of NaCl, KCl or NaCl-KCl mixture. The thickness of the coating obtained depends mainly on temperature and time but not on the initial bath composition. Pyrosol of titanium may have been produced during the process. The microvickers hardness of the titanium coating has been found to be 400∼600 and a salt spray test has revealed high corrosion resistivity.

著者

高木 節雄

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.83, no.4, pp.107-118, 2019-04-01 (Released:2019-03-25)

参考文献数

37

被引用文献数

8 14

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Yielding and deformation behavior was overviewed for polycrystalline ferritic steels with various grain sizes and carbon contents. In the well-annealed ferritic steels, yielding is governed by the mechanism of grain refinement strengthening (GRS) and yield stress follows the Hall-Petch relation as to grain size. Conversely, yielding of cold rolled ferritic steels is governed by the mechanism of dislocation strengthening (DS) and yield stress follows the Bailey-Hirsch relation as to dislocation density. Under the same percentage of deformation, dislocation introduction is promoted with decreasing ferrite grain size and this results in higher yield stress (or flow stress) in specimens with smaller grain size. Yielding elongation appears due to the plastic instability that is realized during the change of strengthening mechanism from GRS to DS. Therefore, the extent of yielding elongation is determined in the relation between yield stress and work hardening behavior of matrix. Temper rolling plays a role to make the strengthening mechanism change from GRS to DS. When the extent of temper rolling is so small as about 1%, yield stress of temper rolled specimens is lowered below that of the as-annealed specimen. This is the reason why yield stress of the temper rolled specimen is lowered below that of as-annealed specimen. In the relation between GRS and DS, there is not additional but competitive relationship.

著者

北田 正弘 桐野 文良 山本 和弘

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.71, no.1, pp.85-89, 2007 (Released:2007-01-01)

参考文献数

22

---

The surface structure of a metallic mirror fabricated in the late Edo period has been investigated. A Sn layer of 100 nm thickness on the mirror surface is observed by cross-sectional Transmission electron microscopy (TEM). Hg is detected in the Sn layer by EDX analysis. This means that the surface Sn layer of the mirror was fabricated using an Hg-amalgam technique. By AES measurement, an Sn-Cu alloy at the interface between the Sn layer and the Cu base metal is detected. The Sn surface has been oxidized. The oxide layer consists of SnO2, SnO•SnO2, SnO and Sn in order of increasing distance from the surface.

著者

砂野 豊治

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.18, no.12, pp.637-640, 1954 (Released:2008-04-04)

参考文献数

6

---

Pure nickel plplates rolled to several thickness were anneald at various temperature, and the manner of their isothermal sofenting was studied, by observing the changes in their tensile strength and the hardness in the progress of annealing. The results obtained were discussed in connection with the influences of the received cold working, for the sake of study on the mechanism of sofenting.

著者

宮本 吾郎 金下 武士 知場 三周 古原 忠

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.79, no.7, pp.339-347, 2015 (Released:2015-07-01)

参考文献数

38

被引用文献数

8 21

---

Attention to lath martensite and bainite in steels has been increasing due to their good mechanimcal properties. Various boundaries bewteen K-S variants contained in those microstructures contribute to their high strength and toughness so that deeper understand of nature of those boundaries is required. EBSD analyses have revealed that different variant grouping tendencies appear depending on composition and transformation temperature, such as variants belonging to the same Bain group, variants sharing the same close-packed plane parallel relationship. Kinematical compatibility (KC) condition can explain variant pairs coupled preferentially in lenticular and thin plate martensite satisfactory. In addition, it is revealed that some of the variant pairs observed in lath martensite and bainite are favorable for the KC condition when double shears are assuemd for lattice invariant shear.