著者

真木 純

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.105, no.7, pp.759-766, 2019 (Released:2019-06-30)

参考文献数

17

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Aluminized steel sheets are very resistant to corrosion in the outdoor exposure environment. We evaluated the corrosion behavior of aluminized steel sheets with a Type1 coating containing around 10%Si but also a Type2 coating not containing Si in a 50-year outdoor exposure test. Both specimens had strong perforation resistance, but those with Type2 coating had superior perforation resistance. The Type2 aluminized steel sheets had two sublayers composed of Fe2Al5 and FeAl2 as the intermediate layer between the aluminized layer and the steel substrate. The FeAl2 phase has less noble potential than steel substrate and the Fe2Al5 phase in an artificial rain water environment. As a result, this layer provided sacrificial corrosion protection for the steel substrate. That was why the specimens with the Type2 coating had better perforation resistance than those with Type1 coating.

著者

片岡 由行 森川 敦史 古主 泰子 牧田 正弘 吉永 亨二 木戸 直範

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.105, no.5, pp.560-565, 2019 (Released:2019-04-30)

参考文献数

4

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An accurate quantitative analysis method including total iron had been proposed for the iron ore analysis by wavelength dispersive X-ray fluorescence spectrometry using fusion method and was accepted at ISO TC 102 meeting in 2010. The project has been proceeded in ISO TC 102/SC 2/WG54 as ISO/WD 9516-2 project. Number of covered elements is 19, and 14 elements among them including total iron are for referee analysis. The calibration discs are prepared only from reagents and the calibration equation includes coexisting component correction, overlap correction, flux/sample and oxidizer/sample mixing ratio corrections. The coexisting component correction method is based on the absorption/enhancement correction coefficients obtained by a FP (fundamental parameter) method so that LOI (loss on ignition) and GOI (gain on ignition) during fusion do not affect to analyzed results. In the verification experiments with 20 certified reference materials, the accuracy obtained by root mean square of the difference between certified values and analyzed values using proposed method was 0.14 mass%, which indicated analytical accuracy could be greatly improved compared with the existing method. For the other components, the values of accuracy obtained were almost same as the existing method. We are conducting final round-robin test in foreign laboratories and have a plan to set the method as an ISO standard.

著者

宮島 明 山田 健夫 安藤 静吾 国岡 計夫 杉山 峻一 神尾 寛 島田 勝彦 角崎 周市 富川 隆信 山田 正義 小峰 勇 米谷 捻 角崎 周市 山田 正義 田辺 英也 森田 博之 入谷 正夫 宇野 義雄 手塚 栄 吉田 謙吾 小橋 正満 山田 信男 宮崎 四郎 西出 輝幸 浜田 一明 小西 敏弘 藤原 洋一 上田 正美 東 良学 片山 知行 高橋 昭夫 吉村 清信 土屋 安夫 天野 虔一 佐藤 俊彦 桑島 英明 浜島 吉男 高橋 亮一 川野 晴雄 横井 玉雄 成合 靖正 高力 満 鎌田 晃郎 高野 道典 山口 久 寺本 和啓 中山 武典

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.64, no.4, pp.S245-S256, 1978

著者

KAWAI H. TAKAHASHI H.

出版者

一般社団法人 日本鉄鋼協会

雑誌

ISIJ international (ISSN:09151559)

巻号頁・発行日

vol.44, no.7, pp.1140-1149, 2004-07-15

参考文献数

6

被引用文献数

5 25

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One of recent discussions is on the floating and sinking motion of packed bed in the hearth part of blast furnace while the molten liquid is stored in and tapped out of the hearth. Such a repetition motion might be profoundly related to the renewal of deadman particles. Thus, further analysis for deadman motion with the iron liquid is necessary to develop a method for controlled or stable furnace operation. In this study, the experiment is performed using a two-dimensional cold model with foaming polymer particles and water. Gas flow is not considered. The particle descending velocity in the shaft of the model is found to decrease with floating of the hearth packed bed and increase with the sinking motion. The deadman renewal rate that is the solid moving rate forced into raceway from the inside of deadman, is estimated by subtracting the descending rate from the total particle discharge rate being controlled at a constant rate. The numerical treatment called Discrete Element Method is also carried out to clarify the renewal mechanism with storing/tapping liquid. It is confirmed from both the experimental and numerical that the deadman particles move gradually into the raceway while storing/tapping liquid is repeated and the renewal of particles occurs in such a way that the older particles are forced to go out of deadman by buoyancy and the new particles comes in to fill deadman through near the top of the deadman during tapping the liquid. The simulation indicates also that the wall normal contact force in the hearth part increases considerably when the particle bed floats.

著者

安田 洋平 下川 智嗣 大橋 鉄也 新山 友暁

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

pp.TETSU-2018-082, (Released:2018-11-01)

参考文献数

27

被引用文献数

2

---

Strain hardening behavior of ferrite layers in the microstructure of drawn pearlite wire is studied theoretically and numerically. It is shown that stress field associated to dislocations could diminish quickly if the dislocations enter the phase or grain boundaries and decompose into smaller segments to distribute along the boundary. Some atomistic simulations of single-phase media validate this phenomenon; dislocations show to pass, decompose or accumulate on tilt-type grain boundaries depending on their atomistic configuration. Mechanical responses of nine-layered pearlite models subjected to tensile load are analyzed by a strain gradient crystal plasticity finite element code, where possible passage or absorption of dislocations is expressed in the model of dislocation mean free path. The critical resolved shear stress for slip systems consists of the lattice friction, the Taylor and Orowan terms and the strain hardening is given by the Taylor one. The density evolution of accumulated dislocations is evaluated by the model of Kocks and Mecking where the dislocation mean free path plays a major role. Results show that the smaller the dislocation absorption ability of the phase boundary and thinner the layer thickness, larger the strain hardening becomes. Slip localization in cementite layers is shown to be suppressed when the strain hardening of ferrite layers is higher, and this trend is consistent with results obtained in previous studies by molecular dynamics simulation and classical elasto-plasticity analyses. Scale sensitive phenomena taking place at phase boundaries in layered structure are briefly discussed in views of atomistic process and continuum mechanics.

著者

雨宮 雄太郎 中田 伸生 諸岡 聡 小坂 誠 加藤 雅治

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.105, no.2, pp.314-323, 2019 (Released:2019-01-31)

参考文献数

28

被引用文献数

5

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For deeper understanding of a dynamic accommodation mechanism of internal stress in pearlite originated from the lattice misfit between ferrite and cementite phases, the lattice parameter ratios of cementite, bθ/aθ and cθ/aθ, were locally analyzed in detail by using the electron backscatter diffraction (EBSD) technique. The EBSD analysis has revealed that lattice parameter ratios of cementite lamellae obviously differ from those of spheroidized cementite particles, which demonstrates that pearlite has a certain amount of internal stress as long as it maintains lamellar structure. The internal stress in pearlite gradually decreased during isothermal holding at 923 K after pearlitic transformation due to interfacial atomic diffusion of iron atoms. However, comparing with theoretical values under Pitsch-Petch orientation relationship, it was understood that large amount of internal stress had been already accommodated upon pearlitic transformation by introduction of misfit dislocations and structural ledges on ferrite/cementite lamellar interfaces. That is, the internal stress of pearlite is dynamically reduced by two different processes; built-in accommodation upon pearlitic transformation and additional time-dependent relaxation after pearlitic transformation. On the other hand, EBSD analysis and neutron diffraction technique gave remarkably different lattice parameters of cementite. From this result, it is concluded that various crystallographic orientation relationships between ferrite and cementite coexist in pearlite. Furthermore, elastic strain energy analysis suggests that the invariant-line criterion on ferrite/cementite interface plays an important role for the selection of orientation relationships in pearlite.

著者

俵 国

出版者

一般社団法人 日本鉄鋼協会

雑誌

鐵と鋼 (ISSN:00211575)

巻号頁・発行日

vol.5, no.4, pp.400-408, 1919-04-25 (Released:2009-07-09)

被引用文献数

1 1

著者

俵 國一

出版者

一般社団法人 日本鉄鋼協会

雑誌

鐵と鋼 (ISSN:00211575)

巻号頁・発行日

vol.6, no.3, pp.253-269, 1920-03-25 (Released:2009-07-09)

著者

藤城 泰志 原 卓也 重里 元一

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.101, no.5, pp.300-307, 2015 (Released:2015-04-30)

参考文献数

25

被引用文献数

2 12

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Effect of the combined addition of molybdenum (Mo) and boron (B) on austenite (γ) to ferrite (α) transformation and precipitation behavior were investigated using low-alloy steels. B-added steel and Mo-B combined steel were held at 923 K (γ region) in order to precipitate boride. B content as precipitates increased and γ to α transformation was promoted with holding time at 923 K. In B-added steel, both M23(C,B)6 and M2B were observed. The transition from M23(C,B)6 to M2B caused by the increase in holding time at 923 K. By contrast, in Mo-B combined steel, no M2B was observed regardless of the holding time. Mo addition suppresses not only the M23(C,B)6 formation but also the M2B formation. M2B contains larger amounts of B than M23(C,B)6. B content as precipitates in Mo-B combined steel was much lower than that in B-added steel due to the suppression of M2B precipitates. The effect of Mo for B containing steel suppresses the precipitation of M23(C,B)6 and M2B and increases more segregated B in austenite grain boundary that contributes to γ to α transformation.

著者

丹羽 貴知蔵 横川 敏雄 森 一美 堤 正克 川合 亜之 藤井 毅彦 荒木 泰治 丸川 雄浄 川上 公成 岡崎 有登 松野 淳一 岡野 忍

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.52, no.3, pp.505-519, 1966-03-01 (Released:2010-10-12)

被引用文献数

3

著者

AMATATSU Masayoshi STUTS Volker GUDENAU Heinrich Wilhelm

出版者

一般社団法人 日本鉄鋼協会

雑誌

Transactions of the Iron and Steel Institute of Japan

巻号頁・発行日

vol.25, no.9, pp.949-952, 1985

被引用文献数

6

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Evaporation of potassium from slag was investigated in order to estimate the effect of chemical composition and temperature. The evaporation rate increased with addition of basic oxide as FeO, CaO and MgO and it decreased with addition of amphoteric oxide such as alumina and titanium dioxide. Addition of MgO substituted by CaO under constant basicity B=(CaO+MgO)/SiO₂ affected positively the delayed evaporation of potassium oxide.

著者

山口 哲夫 成田 宏 谷口 肇 松岡 孝 高橋 政司 平野 坦 高橋 栄治 山田 凱朗 尾内 三郎 田島 喜久雄 佐藤 進 泉 総一 子安 善郎 朝野 秀次郎 広前 義孝 大八木 八七 岡田 秀彌 細井 祐三 湯川 憲一 相崎 守弘 小若 正倫 佐武 二郎 諸石 大司 藤野 允克 松島 巖 上野 忠之 田中 良平 長崎 久弥 許廷 珪 大岡 新之 竹村 右 小原 啓一 長谷川 正義 藤山 新 竹中 康男 深瀬 孝重 遅沢 若一部 伊藤 穣一 岡本 一生 小野山 征生 太田 鶏一 高村 昭 荒川 要 坪井 孝悦

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼

巻号頁・発行日

vol.55, no.3, pp.S216-S224, 1969

出版者

一般社団法人 日本鉄鋼協会

雑誌

鐵と鋼

巻号頁・発行日

vol.10, no.10, pp.b1-b6, 1924

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

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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.

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

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

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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

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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

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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

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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

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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.