著者

杉本 諭 前田 徹 籠谷 登志夫 手束 展規 猪俣 浩一郎

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.42, no.3, pp.202-206, 2003-03-20 (Released:2011-08-11)

参考文献数

20

著者

山末 英嗣 村橋 勲 奥村 英之 石原 慶一

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.71, no.9, pp.763-771, 2007 (Released:2007-09-01)

参考文献数

12

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An abandoned traditional steelmaking in Southwest Ethiopia (Dime) has been restored, and the technology and knowledge used for the operation have been metallurgically analyzed. The restoration was carried out with local blacksmiths from September to October in 2004, and the steelmaking operation including mining, construction of a furnace and charcoal production, etc was successfully performed. Produced sponge iron contains 0.31∼0.48 mass% carbon without any impurities. The yield ratio of the iron was about 40%. The collected slag contains the elements of Fe, Si, Al, K, P, Ti and Mn, which are typical components of slag. The blacksmiths used three kinds of iron ore, named “Balt”, “Bullo” and “Gachi”. The former two ores mainly consist of goethite (α-FeO(OH)) and kaolinite (Al2O3•2SiO2•2H2O). The latter includes calcium phosphate hydrate (Ca3(PO4)2•xH2O) in its white part, as well as the goethite and kaolinite. The reason why the local blacksmiths specifically selected “Gachi” as the best ore for their steelmaking was discussed from the viewpoint of slag forming ability.

著者

秋山 英二

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.56, no.3, pp.230-233, 2017 (Released:2017-03-01)

参考文献数

64

被引用文献数

1 3

著者

大森 俊洋 草間 知枝 喜瀬 純男 田中 豊延 荒木 慶一 貝沼 亮介

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.58, no.3, pp.137-143, 2019-03-01 (Released:2019-03-01)

参考文献数

22

著者

榊 孝 清水 要樹 崎山 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.49, no.3, pp.202-209, 1985 (Released:2008-04-04)

参考文献数

7

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The corrosion behaviour of various commercial alloys was studied by measurements of potentio-dynamic polarization curves, the change in corrosion potential with time and the average corrosion rate. The corrodent used was 48%NaOH solution at temperatures between 373 and 473 K, and the following results were obtained. The corrosion resistance of stainless steels was improved by adding nickel and chromium. Especially, immersion tests showed that ferritic stainless steels containing 27-30% chromium and austenitic stainless steels containing nickel more than 20% possessed excellent corrosion resistance. On the other hand, addition of molybdenum and copper to the stainless steels gave no protective effects as to the alkaline corrosion. When the corrodent was a 48%NaOH solution obtained by the diaphragm process, NaClO3 contained in the solution acted as an oxidizer. Its oxidation powder increased somewhat the tendency of the high chromium steels to become passive, but promoted dissolution of nickel.

著者

Han Lee-Long Lin Chun-Ming Shih Yih-Shiun

出版者

公益社団法人 日本金属学会

雑誌

Materials transactions (ISSN:13459678)

巻号頁・発行日

vol.54, no.5, pp.833-838, 2013-05-01

参考文献数

14

被引用文献数

6

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This study compared cryogenic treatment, ultra-cryogenic treatment, and high-low temperature tempering treatment using ASSAB Stavax ESR, and conducted the following analyses of the prepared specimens: (1) analysis the structure by X-ray diffraction, (3) analysis of the texture of the processed specimens by optical microscopy, (2) using a hardness tester to analyze the changes in hardness of specimens processed by cryogenic and heat treatment, (3) analyzing the hydrophilicity and hydrophobicity by the water contact angle test, and (4) analyzing corrosion resistance by the corrosion resistance test. The experimental results showed that cryogenic temperature affects the amount and shape of the carbides, which are significantly reduced in cases of high-temperature tempering. The water contact angle test analysis showed that the coating film’s water contact angle performance is the best, followed by specimens of ultra-cryogenic treatment, specimens of cryogenic treatment, and specimens of traditional heat treatment. It was found that cryogenic treatment can increase polishability, and empower the specimens with good mold release performance. The coating-film corrosion resistance test showed that ultra-cryogenic treatment and cryogenic treatment can improve corrosion resistance; however, the performances of specimens by traditional heat treatment were the worst.

著者

德永 透子 外本 和嗣 大野 宗一 松浦 清隆

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.81, no.8, pp.389-393, 2017-08-01 (Released:2017-07-25)

参考文献数

8

被引用文献数

1

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The poor corrosion resistance of Mg alloys, which is well known as one of the lightest structural metal materials, limits a wide use of these alloys. In order to dramatically increase not only the corrosion resistance but also the surface hardness of Mg alloys (AZ80), coating with A2024 Al alloy by hot extrusion has been attempted in this study. The coating was successfully realized by hot extrusion of a Mg alloy (AZ80) billet together with an Al alloy plate placed between the billet and the extrusion die. The A2024 Al alloy-coated Mg alloy exhibited an excellent corrosion resistance and no weight loss was observed after immersion in a 5 mass% HCl aqueous solution for 10 min while a weight loss of about 1500 g・m-2 was observed in case of AZ80 Mg alloy without coating under the same condition. The surface hardness of the coated alloy was increased to about 85 HV by aging for 144 h at room temperature after solution treatment for 3 h at 673 K.

著者

鄭 巍巍 庄子 哲雄 糸藤 春喜 張 建華

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.80, no.3, pp.176-185, 2016 (Released:2016-02-25)

参考文献数

18

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The purpose of this study is to analyze the microstructure and chemical composition of the oldest heavy section cast iron cannon in China, which was manufactured at the early Ming dynasty in the year of 1377 with the inscription of Hongwu. It is worthwhile to study any characteristic casting processes and advancement of the heavy section casting technology during the Ming dynasty because the cannon technology could be developed based upon the leading technology of that age. This cannon has been preserved and displayed at Shanxi Province Art Museum. Some microstructural analysis was performed on site by use of portable grinding and polishing tools for the metallurgical examination. In addition, more detailed metallurgical examination by EDX, XPS, high temperature optical microscope (OM) and DSC analysis was performed on a small sample taken from the cannon. Chemical analysis was also performed on the grinding chips and powder collected during the metallurgical surface preparation. A thermodynamic phase diagram was calculated by CALPHAD method for the material with the same chemical composition as measured. After the detailed metallurgical examination and chemical composition analysis, it turned out that the cannon has a chemical composition range of minor elements as: C: 1.36-1.8 mass%, S: 0.58-0.78 mass%, P: 0.61-0.81 mass%, Si: 0.45-0.61 mass%, and shows a uniform hypereutectoid microstructure. Taking into account the evidence of no microstructural gradient from a surface to inside which is not common in ancient decarburized cast iron, the cannon is highly likely to be made by a cast steel rather than by a cast iron.    Non-metallic inclusions are observed both by OM and by a scanning electron microscope (SEM) on the sample. A high temperature optical microscope with an in-situ heating capability was used to directly observe any phases with a lower melting temperature. Also DSC analysis was performed on the sample to examine any phase change at some specific temperature. Based upon these observations and analysis, it was concluded that the Hongwu cannon was made by cast steel with a hypereutectoid microstructure. This microstructure contained a eutectic phase in pro-eutectoid cementite, which suggests a formation of steadite Fe-Fe3C-Fe3P with a low melting temperature of 1227 K. This finding strongly suggests that, instead of cast iron technology, cast steel technology had already existed and was put in use for heavy-section cannon production during early Ming Dynasty in China.

著者

飯塚 敏彦

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.33, no.8, pp.1044-1045, 1994-08-20 (Released:2011-08-11)

参考文献数

4

著者

桐野 文良 大野 直志 田口 智子

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.3, pp.87-96, 2019-03-01 (Released:2019-02-25)

参考文献数

16

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The metal craft production techniques for an ancient Chinese coin named Ittou in the Shin period of ancient China were studied from material science viewpoints. This cultural artefact was manufactured in the Shin period of ancient China. An infrared image shows the surface state and the materials absorbed on the surface. According to infrared images of the cultural artefact, roughness on the surface of this coin was created on cooling during mintage. UV-fluorescence images show luminescence at corrosion products and yellow soil. In X-ray transmission images, some voids in this coin were observed, indicating the metal craft production technique used during this period. The main element of this cultural artefact is Cu and other elements are Sn and Pb. X-ray diffraction patterns indicate the presence of Cu-Sn base intermetallic compounds. Ittou coins are made from bronze. The characters on the coins were formed using an inlay technique called zougan. Yellow soil adhered to the surface of the examined coin from where it was excavated. The material used to form the characters on the coin is 10 mass% Cu-Au alloy, and flaws were observed on the surface of the characters. The compositions of ancient Kan coins produced between the east Kan and west Kan periods were also analyzed. The composition of these ancient coins was the same as that of the coin from the Shin period of old China, indicating that the same metal craft production technique was used in both periods. These techniques were improved in this period, enabling many coins to be manufactured.

著者

古林 孝夫 間宮 広明 中谷 功

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.38, no.8, pp.638-644, 1999-08-20 (Released:2011-08-11)

参考文献数

23

被引用文献数

1

著者

林 和彦

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.74, no.7, pp.394-403, 2010 (Released:2010-07-01)

参考文献数

20

被引用文献数

1 2

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Bismuth based high temperature superconductor has discovered by Dr. Maeda at NIMS (National Institute for Materials Science). Just after the discovery of this material, Sumitomo Electric has carried out the R&D on long length and high performance wire, and many application prototypes for more than 20 years. As a wire manufacturing technology, CT-OP (controlled over pressure sintering) process is very effective to make high performance wire. Power cable and ship propulsion motor applications using bismuth based superconducting wire are highly expected.

著者

松本 修 村井 康生 津田 陽一 鈴木 信久

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.37, no.4, pp.274-276, 1998

著者

山縣 裕

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.38, no.7, pp.581-585, 1999

著者

榎本 正人

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.54, no.2, pp.65-71, 2015 (Released:2015-02-01)

参考文献数

18

被引用文献数

2

著者

野田 哲二 工藤 清勝 佐藤 教男

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.37, no.9, pp.951-957, 1973 (Released:2008-04-04)

参考文献数

22

被引用文献数

18 11

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The anodic passivation film formed on iron in neutral borate-buffer solution has been studied by using ellipsometric, electrochemical, and gravimetrical techniques. The film can be dissolved from its outer surface by applying a cathodic current in borate-buffer solution at pH 6.35 in which the reductive dissolution,(This article is not displayable. Please see full text pdf.) \ oindentproceeds at 100 per cent current efficiency. Ellipsometric measurements carried out during the galvanostatic-cathodic reduction of the film in this solution reveals that the film consists of two layers, an inner layer with the optical constant 3.0−0.5i and an outer layer with the constant 1.8−0.1i. It is also shown that the density of the inner layer is in agreement with that of γ-Fe2O3.The inner layer thickness increases linearly with the passivating potential, and the potential extrapolated at zero thickness of the inner layer corresponds to the equilibrium potential of the anodic formation of γ-Fe2O3,(This article is not displayable. Please see full text pdf.) \ oindentThe outer layer, however, is not directly related to the anode potential. Thermo-gravimetrical measurements indicate that the film contains some amount of water which is concentrated in the outer layer. The average composition of the outer layer is estimated as Fe(OH)3.A film model is proposed in which the inner layer of anhydrous γ-Fe2O3 is the cause of the potential drop in the film producing a field intensity of 5.6×106 V/cm and the outer layer of hydrous ferric oxide depends on the solution environment and passivation process.

著者

河村 能人 井上 明久

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.41, no.9, pp.644-649, 2002-09-20 (Released:2011-08-11)

参考文献数

21

被引用文献数

2 2

著者

戸高 義一 梅本 実 渡辺 幸則 土谷 浩一

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.67, no.12, pp.690-696, 2003 (Released:2008-04-24)

参考文献数

30

被引用文献数

15 24

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The surface nanocrystallization of various steels by air blast shot peening was investigated. It was found that nanocrystalline layers can be produced when higher shot speed and longer process period than those of conventional shot peening were applied. The produced nanocrystalline layers are several μm thick and show extremely high hardness. The layers have clear boundaries with the adjacent work-hardened regions. By annealing, slow grain growth without recrystallization is observed in the layers. Those characteristics are similar to those observed in the nanocrystalline layers produced by other techniques, such as ball milling, ball drop and particle impact deformations.

著者

長谷川 雅幸

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.35, no.2, pp.93-102, 1996-02-01 (Released:2011-08-11)

参考文献数

35

被引用文献数

8 9

著者

山縣 裕

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.35, no.12, pp.1325-1332, 1996-12-20 (Released:2011-08-11)

参考文献数

33

被引用文献数

3 5