著者
牛尾 誠夫
出版者
The Iron and Steel Institute of Japan
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.73, no.10, pp.1309-1315, 1987-08-01 (Released:2009-06-19)
参考文献数
23
被引用文献数
1 2
著者
角山 浩三 今中 誠 古川 九州男 岸田 朗 山田 恭裕
出版者
The Iron and Steel Institute of Japan
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.75, no.11, pp.2090-2097, 1989-11-01 (Released:2009-06-19)
参考文献数
5
被引用文献数
4 4

The influence of base metal surface roughness parameters on the clarity of painted automotive cold rolled sheet steels was investigated. The sheet steels were dull finished by shot blasting, electro-discharge texturing or laser dull texturing. It was found that the painted clarity improved with decreasing of Ra, while it scarcely depended on PPI. Characteristic of the surface profiles of base metal was the waviness with wavelength of hundreds micron. Whose trace remained after coating and deteriorated the clarity. In shot blasting, the dendritic microstructure and the statistical fluctuation of grit collision generated the waviness and made it difficult to control its wavelength. And, in electro-discharge texturing, it is suggested, controlling the waviness is difficult similarly. In laser dull texturing, it was possible to reduce the wavelength of waviness to less than hundreds micron and then to improve the clarity without deteriorating the press formability. A larger fraction of flat portion in laser dull texture was also responsible for the improvement of clarity.
著者
小山 元道 澤口 孝宏 津﨑 兼彰
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.104, no.4, pp.187-200, 2018 (Released:2018-03-31)
参考文献数
86
被引用文献数
6

This paper presents an overview of the recent works on dynamic strain aging (DSA) of Fe-Mn-C austenitic steels including Hadfield and twinning-induced plasticity (TWIP) steels. First, a model of the DSA mechanism and its controlling factors are briefly explained in terms of Mn-C coupling and dislocation separation. Then, we introduce the effects of DSA on mechanical properties such as work hardening capability, uniform elongation, post-uniform elongation, and fatigue strength. Specifically, we note the pinning effect on extended dislocation for the work hardening, the Poretvin-Le Chatelier banding effect on damage evolution for the elongation, and the crack tip hardening/softening effect on crack resistance for the fatigue strength. We believe that this overview will help in designing advanced high-strength steels with superior ductility and fatigue resistance.

1 0 0 0 OA 随想

著者
河西 健一
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.54, no.13, pp.1325-1326, 1968-11-01 (Released:2010-10-12)
著者
武智 弘
出版者
The Iron and Steel Institute of Japan
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.78, no.3, pp.339-345, 1992-03-01 (Released:2009-05-29)
参考文献数
15
被引用文献数
1
著者
萬谷 志郎 井口 泰孝 本多 弘 石塚 晴彦
出版者
The Iron and Steel Institute of Japan
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.71, no.7, pp.846-852, 1985-05-01 (Released:2010-01-19)
参考文献数
18
被引用文献数
2 3

The heat of mixing of silica(β-cristobalite) with liquid wustite melted in an iron vessel has been directly measured at 1420°C by the modified isoperibol calorimeter(iso-thermal jacket type). Mixing of solid silica with liquid wustite is an exothermic reaction and the measured heat, ΔHFetO(l)-SiO2(β-cristobalite), is about-900cal/mol at the fayalite composition. Heats of mixing of liquid silica with liquid wustite, ΔHMFetO(l)-SiO2(l), are obtained by the combination of this direct measured results and heat of fusion of SiO2 in the reference. This result is discussed in comparison with the estimated values by the thermochemical data and by the assumption of the regular solution.
著者
星 秀夫 佐々木 稔
出版者
The Iron and Steel Institute of Japan
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.91, no.1, pp.103-107, 2005-01-01 (Released:2009-06-19)
参考文献数
4
被引用文献数
2 4

供試材である日本刀の三振りを切断し多くの項目について調査した結果,炭素以外の諸元素が極めて少ない高純度の炭素鋼であることが鍛接性を良くし耐食性を高め,また刀身全表面に圧縮残留応力をもたせることが日本刀の靱性をさらに強化すること等が確認できたことである.
著者
黒岩 大助
出版者
The Iron and Steel Institute of Japan
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.62, no.7, pp.916-925, 1976-06-01 (Released:2010-02-22)
被引用文献数
1
著者
上部 伊織 道原 健人 森下 浩平 柳楽 知也 安田 秀幸
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.12, pp.678-687, 2017 (Released:2017-11-30)
参考文献数
27
被引用文献数
5

This study demonstrates in-situ measurement of solute partition coefficient in multicomponent alloys, using X-ray transmission imaging and X-ray florescence spectroscopy. The developed technique was applied to determine partition coefficients of Cr, Ni and Mo between δ phase and liquid phase in Fe-17.4Cr-12.6Ni-2.0Mo-1.6Mn-0.6Si alloys (mass%). In the observation and measurement, X-ray fluorescence spectra were directly obtained by irradiating the incident X-ray beam (23keV) to the solid phase or the liquid phase near solid/liquid interface. The partition coefficients were simply determined from the X-ray florescence analysis. In addition, successive measurements during unidirectional solidification allowed to measure change in partition coefficient along solidification path. During the solidification, partition coefficients of Cr, Ni and Mo changed from 1.01 to 1.08, from 0.76 to 0.70 and from 0.86 to 0.74, respectively. The present study proved that the developed technique was applicable to determine partition coefficients of 3d and 4d transition elements of which characteristic X-ray energies ranged from 4 to 20keV.
著者
生沼 駿 高久 歴 中谷 祐二郎 齊藤 大蔵 今井 潔
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.9, pp.549-554, 2017 (Released:2017-08-31)
参考文献数
14

In this study, the effect of Ni and Cr composition on mean thermal expansion coefficient (CTE) and γ’-Ni3 (Al, Ti) strengthening microstructure of austenitic heat resistant steel, Alloy 286, was investigated. The measurements revealed that the CTE of Alloy 286 decreases at wide range of temperature up to 800°C with addition of Ni and reduction of Cr concentration. The magnetization-temperature curve showed that the magnetic transition temperature, which the alloy transforms to ferromagnetic state to paramagnetic state, raise with addition of Ni and reduction of Cr. The CTE of alloys had good relations with magnetic transition temperature and mean valence electron numbers (e/a), suggesting that the magneto-volume (invar) effect and the suppression of lattice expansion strongly appear at high Ni and low Cr concentration. Ni and Cr optimized alloy exhibits γ phase microstructure with fine γ’ particles dispersed within the grain, and the hardness of grain interior is larger than Alloy 286. This alloy has low CTE comparable to conventional ferritic steels, together with higher strength than conventional austenitic steels.
著者
本間 祐太 橋 邦彦 佐々木 元 大川 琢哉 長井 寿
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.10, pp.579-588, 2017 (Released:2017-09-30)
参考文献数
18
被引用文献数
2

Better balance of strength and toughness is a strong demand for the ASTM A707 L5 grade steel. In the present study, therefore, the combination of hardening by Cu precipitates and toughening by quenching from a dual-phase (α+γ) region, so-called intercritical quenching or lamellarizing, has been investigated for a better balance of strength and toughness. The combination procedure resulted in a drastic increase in toughness at low temperatures with a slight decrease in yield strength.The lamellarizing brought about a complicated microstructure with meandered high angle grain boundaries (HAGB) and fine grains bordered by the HAGB. The final microstructure was composed of granular bainitic ferrites without retained γ and basically dual of a softer phase and a harder phase. The softer phase inherited the not-transformed α phase region in lamellarizing and contained coarse Cu precipitates. The harder phase inherited the transformed γ phase region in lamellarizing and contained no Cu precipitates. Hence, over-aging of Cu precipitation in the softer phase might result in the slight decrease in yield strength.In the present steel, the retained γ has nothing to do with the improved toughness. Hence, the effective grain size (dEFF) approach was verified to account for the microstructural effect on toughness. The unit microstructure to determine the dEFF was identified to be the bainitic ferrite grain bordered by the HAGB. The refinement of the dEFF through lamellarizing can be attributed to the improved toughness.
著者
荒木 理 藤井 浩平 赤間 大地 土山 聡宏 高木 節雄 大村 孝仁 高橋 淳
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.8, pp.491-497, 2017 (Released:2017-07-31)
参考文献数
28
被引用文献数
15

Effect of aging treatment at 373 K on Hall-Petch coefficient (ky) was investigated in consideration of the change in friction stress associated with carbide/nitride precipitation in ferritic steels containing 60 ppm carbon or nitrogen (C60 and N60). Tensile tests revealed that the ky was monotonously increased with increasing aging time in both steels, and also, C60 exhibited a larger ky value than that of N60 under the same aging time. As a result of 3DAP analysis and theoretical calculation for grain boundary segregation of carbon and nitrogen, the ky corresponded to the amount of carbon and nitrogen existing at grain boundary. There was no difference in the effect on ky increment between both elements. The larger ky in C60 under the same aging condition was due to the larger amount of segregated carbon compared with nitrogen.
著者
神野 憲博 濱田 純一 金子 賢治
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.9, pp.539-548, 2017 (Released:2017-08-31)
参考文献数
50
被引用文献数
1

In this study, Cu-added ferritic stainless steel sheets were investigated to understand the influences of Cu contents on the high-temperature strength during the high-temperature deformation. High-temperature proof stress at 700~900°C was improved greatly by addition of more than 1% of Cu. In the case of static aging at 900°C, the rod-shaped ε-Cu particles satisfied the K-S orientation relationship with the α matrix, but spherical-shaped ε-Cu particles without specific orientation relationship started appearing during the tensile deformation at 900°C. Similarly, the spherical-shaped and fine ε-Cu particles were observed during the thermal fatigue process in the temperature range from 200°C to 700°C with a 50% restriction ratio. During the observation using the high-temperature in-situ TEM straining, it was clarified that the ε-Cu particles were divided by dislocation shearing and parts of them were found dissolved. According to the LSW theory, it was suggested that the microstructure with fine and spherical-shaped ε-Cu particles was formed by the repetition of dissolution and precipitation during the high-temperature deformation.
著者
土田 紀之 大倉 誠史 田中 孝明 田路 勇樹
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.10, pp.597-605, 2017 (Released:2017-09-30)
参考文献数
39
被引用文献数
3

High-speed deformation behavior and their strain rate dependence on mechanical properties of 1 GPa-grade TRIP-aided multi-phase (TRIP) steels were studied. The strain rate range in this study was between 3.3×10–6 and 103 s–1, and the effect of retained austenite (γR) shapes on TRIP effect in the 1 GPa-grade TRIP steel was also focused on. The effects of strain rate on tensile strength and flow stress in the TRIP steels were small whereas that on uniform elongation was large. The strain rate dependences on tensile strength and uniform elongation in the TRIP steels were more closely to those of the metastable austenitic stainless steels than the conventional TRIP and dual-phase steels. The 1 GPa-grade TRIP steel with the γR shape of needle-like showed better tensile properties and absorbed energy in the present strain rate range. The volume fraction of γR more than 20% and the matrix microstructure of martensite seem to be important factors in the high-strength TRIP steels.
著者
森 滋勝
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.76, no.6, pp.817-824, 1990-06-01 (Released:2010-05-07)
参考文献数
59

最近の流動層“工学”の進歩を述べなければならないのだが,ここでは,最近の研究と技術開発について現在注目を集めているテーマを例として取り上げ,その成果と課題を紹介する.鞭,森,堀尾による“流動層の反応工学”が刊行されてから既に5年余りが経過した.本書の1・2節で,流動層の歴史を4期に分け,“第3期で流動化現象を覆っていた未知のベールはほぼ取り除かれ,粒子分散系の挙動の総合的解明に大きな一歩を踏み出したのが現在の第4期である.”と述べたが,その後,流動化粒子や操作条件の拡大にともない,新しいベールに包まれたより一般的な粒子分散系の解明に向けてますます盛んに研究が行われている.この間に,特集記事や成書が刊行された.流動層に関する第4~6回の国際会議も開催され,それぞれのプロシーディングが刊行されている.さらに特筆されるのは,新しく循環流動層だけについての国際会議が既に2回開催されたことで,第3回が1990年10月に名古屋で開催されることになっている.新しい研究の展開に大きな影響を与えたのは,この間もやはり流動層技術の新たな展開であった.1980年代に入って1970年代の世界を巻き込んだエネルギー問題も石油価格の低下により一応鎮静化した.しかし,流動層燃焼技術の開発は研究費の削減などの逆風にもかかわらず大きな進展を見た.特に,新しい燃焼技術として登場した循環流動層燃焼装置(CFBC)は,中規模用ボイラーとしてヨーロッパにおいて大成功を納め,その後,米国やアジアにおいても主に産業用ボイラーとして急速に導入されている.このCFBCの成功により,循環流動層(CFB)に関する研究がいっせいに展開され,国際会議が開催されるまでになったのである.一方,エネルギー問題に続いて主に我が国において起こったファインセラミックスをはじめとする新素材ブームは,流動層を使用した化学気相成長法(CVD)等の新しい反応器の開発やサブミクロン等の微細粒子の流動化に関する研究の強い推進力となっている.さらに,石油製品のいっそうの白物化に対応するため,より重質な油分が処理できる流動層接触分解プロセス(FCC)の開発や,高度な環境保全に対応できる下水汚泥の焼却,廃棄物や都市塵芥の燃焼とエネルギー利用プラントの開発等は,流動層に対してより高度で精密な設計と操作を要求し,詳細な基礎研究がますます重要になっている.また,最近では石油化学製品の好調な需要に支えられて各種の新しい触媒反応器の大型化や建設が計画されており,一部では既に稼働しはじめているが,今後の動向は世界的な経済情勢の動向に大きくかかわっている.鉄鋼分野では,既に読者の方々もよく御承知のように,溶融還元プロセスのための流動層を用いた鉄鉱石の予備還元炉の開発が推進されている.ここでは,まず流動化現象に関する最近の研究として,循環流動層と微細粒子の流動化を取り上げその現状と課題を紹介する.次に,最近の流動層技術の展開の例として,FCCプロセス,燃焼プロセス,新素材製造技術を取り上げ,最近の展開を紹介する.
著者
杉本 公一 小林 純也 北條 智彦
出版者
一般社団法人 日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.103, no.1, pp.1-11, 2017 (Released:2016-12-31)
参考文献数
132
被引用文献数
1 24

This paper introduces the microstructure, retained austenite characteristics, strain-induced transformation-deformation mechanism and mechanical properties of transformation-induced plasticity (TRIP)-aided martensitic (TM) steels for the automotive applications. Because the microstructure consists of a wide lath-martensite structured matrix and a mixture of narrow lath-martensite and metastable retained austenite (MA-like phase), the TM steel produced a good combination of tensile strength and cold formability. If Cr and/or Mo were added into 0.2%C-1.5%Si-1.5%Mn steel to enhance its hardenability, the resultant TM steel achieved superior notch fatigue strength and impact and fracture toughness to conventional structural steel such as SCM420. These enhanced mechanical properties were found to be mainly caused by: (1) plastic relaxation of the stress concentration, which results from expansion strain on the strain-induced transformation of the metastable retained austenite; and (2) the presence of a large quantity of finely dispersed MA-like phase, which suppresses crack or void initiation and subsequent connection.
著者
杉江 英司 松岡 雅典 秋山 俊弥 三村 宏 住友 芳夫
出版者
社団法人日本鉄鋼協会
雑誌
鉄と鋼 (ISSN:00211575)
巻号頁・発行日
vol.69, no.9, pp.1190-1197, 1983
被引用文献数
2

High Strength Line Pipe Research Committee in the Iron and Steel Institute of Japan has conducted five full scale burst tests with air pressure of 12.0 MPa on pipes of 48 in. in diameter and 0.720 in. in wall thickness of API. grade X 70, made with both controlled rolled steels and quenched and tempered steels. The arrestability of the pipes for the propagating shear fracture can be evaluated by Charpy absorbed energy and is not influenced by the existence of separation. The critical Charpy energy for arresting the shear fracture depends on the distance in which the crack should be arrested, and this phenomenon is well explained by solving the equation which governs the change in the crack velocity. Under the present test condition, the critical Charpy energy is 180 J for the arrest within one pipe length and 130 J for the arrest within two pipe length.