著者

吉崎 鴻造

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.47, no.2, pp.170-172, 1961-02-01 (Released:2010-10-12)

著者

鈴木 章 内山 郁 太田 豊彦 飯田 義治 野中 浩 小川 治夫 岡野 忍 成田 貴一 山田 史郎 谷口 政行 久次米 章 鈴木 武 江藤 重任 梅田 洋一 山田 恭暉 武井 格道 島田 春夫 大羽 信夫 長岡 豊 岩田 至弘 小池 与作 満尾 利晴 高見 敏彦 北材 征義 角田 方衛

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.53, no.5, pp.S40-S46, 1967

著者

山﨑 重人 田中 將己 森川 龍哉 渡部 康明 山下 満男 和泉 栄

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-2021-069, (Released:2021-08-05)

参考文献数

46

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Cleavage fracture of C14 Fe2W Laves phase was investigated using crystal orientation measurement with scanning electron microscopy and first-principles calculations. Trace analysis of the orientations of cleavage planes reveals that cleavage fracture occurred at five types of crystal planes of (0001), {1100}, {1120}, {1101} and {1122}, among which the fracture at (0001) is the most preferable. The first-principle calculations of the surface energy for fracture, Young's modulus, and Poisson's ratio showed that the minimum fracture toughness value of 1.62 MPa·m1/2 was obtained at (0001). The tendency that the values of calculated fracture toughness become larger with the higher indexed planes is almost the same as the frequency of the types of cleavage planes in the trace analysis. It is concluded that the fracture toughness of C14 Fe2W Laves phase is controlled by the surface energy for fracture and Young’s modulus.

著者

田村 節夫

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.68, no.15, pp.2108-2115, 1982

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高炉耐火物の損傷機構と対策,および耐火物侵食診断技術の現状について概説した.<BR>耐火物は種々の原因によつて損傷されるが,いずれにおいても,何らかの形で炉内温度変動が関与しており,損傷の直接原囚として,遠因として,あるいは加速要因として作用する.従つて,炉況の安定が耐火物損傷防止の基本であり,また逆に損傷防止が炉況の安定につながることから,耐火物の寿命延長と安定操業は不可分の関係にある.<BR>また損傷機構の解明は,耐火物の材質・構造選定の上からも重要であり,このため損傷過程にある耐火物サンプルの解析あるいは試験室的な損傷状況の再現試験が有力な手段となろう.<BR>診断技術については,単に侵食量の推定だけでなく,れんが内で生じる現象,たとえば,き裂の発生,れんがの変質,溶銑の侵入,付着物の形成などの検出,推定まで含めた診断技術の開発が必要である.

著者

宅田 裕彦 蟹江 智文 磯貝 栄志 吉田 亨

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.6, pp.553-559, 2005-06-01 (Released:2009-06-19)

参考文献数

13

被引用文献数

11 2

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In this study, first, the limit strains of a few types of high-strength steel sheets under various strain paths from balanced biaxial stretching to uniaxial tension are examined by the Marciniak-type in-plane biaxial stretching test. They are compared with those derived from some criteria for ductile fracture. It is found that the fracture strains derived from the criterion proposed by Cockcroft and Latham give the best fit to the experimental results. Next, as fundamental 3-dimensional press forming processes, the square cup deep drawing and the T-shape forming of the high-strength steel sheet are analyzed by the finite element method combined with the ductile fracture criterion. The dynamic explicit finite element program LS-DYNA ver. 970 with membrane shell is used. The comparison with the experimental results demonstrates that the fracture initiation sites and the critical punch strokes are successfully predicted by the present approach.

著者

天辰 正義

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.47-54, 2005-01-01 (Released:2010-05-25)

参考文献数

7

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(1)出土鉄滓の化学成分と製鉄工程の分類出十鉄滓の製鉄工程上の分類は,鉄滓の化学成分の分析結果によりT.FeとTiO2との関係図,および造滓成分(Slag Component SC=SiO2+Al2O3+CaO+MgO)とT.Feとの関係図から,砂鉄系製錬滓,鉄鉱石系製錬滓,砂鉄系精錬鍛冶滓,砂鉄系鍛錬鍛冶滓および付着滓に判別が可能であり,FeO-TiO2-SiO22状態図に基づいて検討した結果,以下の成分範囲に分類された。砂鉄系製錬滓は,20%≦TFe≦55%で1%≦TiO2≦40%の範囲にあって,SC≒30%である。また鉱石系製錬滓は,30%≦T,Fe≦50%でTiO2≦1%の範囲にあって,30%≦SC≦56%の範囲にある。砂鉄系精錬鍛冶滓は,45%≦TFe≦65%で,05%≦TiO2≦15%の範囲にあって,20%≦SC≦30%の範囲にある。砂鉄系鍛錬鍛冶滓は50%≦TFe≦70%で,TiO2≦15%の範囲にあって,SC≦20%の範囲にある。付着滓は,T.Fe≦20%で,60%≦SC≦90%の範囲にある。TiO2≦0.5%では,砂鉄系と鉱石系の鍛冶滓の判別は難しいが,成分比MnO/TiO2のグラフから判別ができる場合がある。半還元砂鉄(含鉄滓),金属鉄と鉄滓が共存している鉄塊系遺物や銃化鉄を含む不均質な鉄津の判別では,化学成分の分析結果のみでは鉄滓の分類は難しい。X線回折や顕微鏡組織観察の結果も加え,さらに資料の考古学的検討の結果も配慮する必要がある。(2)砂鉄製錬の特徴造滓成分をSC=SiO2+Al2O3+CaO+MgOで代表し,T.Feとの関係を図示し,得られた分析データ群から平衡状態図において特定できる組成の特異点や外挿点との関係を解析した。砂鉄系製錬津のSCは,鉱石系製錬滓のSCより低くなるが,TiO2=0%から40%に増加しても,シリカ成分は40%から30%に減少するだけで鉄滓の融体化反応が維持されていたと推定された。すなわち,砂鉄中の二酸化チタン含有量が高い始発原料であっても,融体化反応は類似の造滓成分(SC≒30%一定)と同じような温度条件(約1250℃)で可能であるという砂鉄製錬の特徴が,平衡状態図の液相線と分析データの解析から得られた。

著者

相原 安津夫

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.67, no.1, pp.35-46, 1981-01-01 (Released:2009-06-19)

著者

北野 智靖 田川 哲哉 粟飯原 周二 Mirco Daniel CHAPETTI 宮田 隆司

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.83, no.6, pp.401-406, 1997-06-01 (Released:2009-06-19)

参考文献数

19

被引用文献数

2 1

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The influence of microstructure on non-propagating behavior of fatigue crack below the fatigue limit was investigated using low carbon steels with three different microstructures simulated heat affected zone of welds. Notched round bar specimens with different stress concentration factors were fatigued under axial loading at the stress ratios R=-1 (tension-compression). Fractographic and metallographic observations of non-propagating cracks at the stress level below fatigue limit were examined, and correlation between non-propagating crack and microstructures was investigated. Non-propagating cracks could be classified as Stage I or Stage II, depending on the microstructure and notch root radius. In the case of dull-notched specimens, where the notch factor in fatigue is proportional to stress concentration factor, the non-propagating crack is Stage I type regardless the microstructure, although Stage II type cracks were observed in sharp notched specimens for particular materials. The criteria for both Stage I and Stage II type non-propagating crack were discussed on the basis of the point stress model and fracture mechanics.

著者

福山 誠司 横川 清志 山田 良雄 飯田 雅

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.6, pp.860-869, 1992-06-01 (Released:2009-05-29)

参考文献数

43

被引用文献数

8 14

著者

西野 知良 本間 浩夫

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.56, no.7, pp.859-868, 1970-06-01 (Released:2010-10-12)

参考文献数

66

被引用文献数

2 1

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The dependence of the yield stress of mild steel at low temperatures on grain size, strain rate and temperature was studied mainly by compressive deformation test.(1) The following equation relating strain rate (ε), temprature (T) and frictional stress (σt) of Petch equation was obtained;This is applicable when at is in the range of 8.7 to 28.2 kg/mm2. Strain rate exponent n and activation energy E are constant, both being independent on temperature, strain rate or stress. Above this stress level, n becomes larger but E is substantially invariable.(2) According to the study on BCC metals, it can be said that they behave in a similar manner to mild steel. That is, is is in the range of 7 to 9, being constant and specific to BCC metals, and in addition, E is approximately proportional to an energy of μb3, where μ is the shear modulus and b the Burgers vector.(3) The relations between strain rate, grain size and ductile-brittle transition temperature were studied by using the above equation, and the calculated temperatures are generally in accordance with the measured values.

著者

藤尾 和樹 山本 厚之 西川 進

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.7, pp.372-377, 2015 (Released:2015-06-30)

参考文献数

11

被引用文献数

3 3

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Seizure tests were carried out on Ni-Cr-Mo abrasion resistant cast irons containing different amounts of graphite and eutectic carbides. Specimens were prepared with changing Cr and Ni contents based on 2.3% C-1.5% Si- 0.6 Mn- 1.8 Mo iron. Surfaces of the test pieces were finished with mechanical grinding or electro-spark machining up to roughness of Ra:0.30 ~ 0.35. Seizure properties were evaluated with using a high peripheral speed wear tester. Higher load was applied for evaluating seizure property, while lower load was applied for friction coefficient. Weight loss was also measured after testing. Surfaces of the specimen after seizure test were observed with SEM. The specimens with higher amounts of graphite showed lower friction at the early stage of seizure tests. When the testing load was increased, seizure was significantly occurred on the specimen with graphite. The effect of graphite for lubrication was also diminished in the case of wear tests under lower load except the early stage of testing. The electro-spark machining for surface finishing lead to exfoliation of graphite from the surface resulting in increase in friction coefficient. The specimen with higher amount of carbides showed superior wear properties.

著者

成瀬 亘

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.64, no.5, pp.650-658, 1978-04-01 (Released:2010-02-22)

参考文献数

15

著者

徳田 昌則 吉越 英之 大谷 正康

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.56, no.14, pp.1899-1915, 1970-12-01 (Released:2010-10-12)

参考文献数

123

被引用文献数

21 9

著者

大山 伸幸 岩見 友司 山本 哲也 町田 智 樋口 隆英 佐藤 秀明 佐藤 道貴 武田 幹治 渡辺 芳典 清水 正賢 西岡 浩樹

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.97, no.10, pp.510-518, 2011-10-01 (Released:2011-10-01)

参考文献数

42

被引用文献数

3 8

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JFE Steel Corporation developed the hydrogen-based gas fuel injection technology for sintering machines to improve sinter quality without increasing coke breeze ratio. With the technology, it is possible to extend the temperature zone between 1200°C and 1400°C by injecting the gaseous fuel from the top surface of the sintering machine as a partial substitute for coke breeze. Theoretical and experimental studies were carried out to verify the effect of the gaseous-fuel injection technology on pore structure in the sinter cake with the X-ray CT scanner and sintering pot test.It is important to hold the temperature between 1200°C and 1400°C in order to produce high strength and high reducibility sinter. The liquid phase ratio can be increased with extending the proper temperature zone by applying the gaseous fuel injection technology. The increase in liquid phase ratio promotes the combination of pores (1–5 mm) and sinter strength is improved. At the same time, the pores over 5 mm growth are promoted and the permeability is improved in the sintering bed. Moreover, the low-temperature sintering process depresses the iron ore self-densification. Micro pores under 1 μm remain in unmelted ores and improve sinter reducibility. As a result, the technology enables to improve the pore structure in the sinter cake and sinter quality.The technology was put into commercial operation at Keihin No. 1 sinter plant in January 2009 and stable operation has continued up to the present. As a result, the energy efficiency in the sintering process is greatly improved, and it has been achieved to reduce CO2 emissions by a maximum of approximately 60000 t/year at Keihin No. 1 sinter plant.

著者

村尾 明紀 柏原 佑介 大山 伸幸 佐藤 道貴 渡壁 史朗 山本 耕司 福本 泰洋

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.102, no.11, pp.614-622, 2016 (Released:2016-10-31)

参考文献数

30

被引用文献数

3 4

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Increased gas utilization and improved permeability have been desired in order to achieve low RAR (Reducing Agent Rate) operation of blast furnace. Coke mixed charging in the ore layer is one effective measure for realizing these improvements. A burden distribution control technique for mixing small coke at a blast furnace with a parallel type and center feed type bell-less top were developed and investigated in an experiment with a scale model of an actual blast furnace at JFE Steel. The scale model consists of an ore bin, a coke bin, a surge hopper, belt conveyers, a bell-less top and a model furnace to simulate the charging system of the actual blast furnace. The mixed coke ratio at the furnace top was controlled by the discharge pattern of mixed small coke and ore, and mixing position. The optimum patterns were founded to discharge the small coke from the coke bin after the ore discharged from ore bin in center feed bell-less top, and to discharge the small coke on the ore at front of quarter part overlapped in parallel type bell-less top. These patterns were applied to the actual blast furnace, and the improvement of permeability in a furnace was confirmed by the effect of increase the mixed small coke yield into ore layer.

著者

篠竹 昭彦 内藤 誠章 尾松 保彦 赤木 一志 坪田 淳 村瀬 伸 菊池 善悦 鈴木 啓之

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.99, no.3, pp.185-190, 2013 (Released:2013-02-28)

参考文献数

7

被引用文献数

1 2

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In the scrap-melting operation of shaft furnaces, an operation technology with use of 100% small size blast furnace coke for solid fuel instead of typically utilizing foundry coke has been established. An operation technology with use of 100% steel scrap without using return scrap containing 3-4 % carbon for ferrous raw material, and 70% or more of steel scrap consists of shredder scrap, has been established as well.This technology was first developed with one-stage tuyere operations using only lower tuyeres. Next two-stage tuyere operations using lower and upper tuyeres has been developed to explore more efficient operation.In the two-stage tuyere operation, the number of pipes, the diameter, and the protruding length of the upper tuyeres were examined as parameters, an operation technology with high efficiency was established, which enabled us to achieve high productivity and low coke ratio.

著者

的場 幸雄 平田 賢 遠藤 倫正

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.69, no.7, pp.874-879, 1983

著者

松本 和久 秦野 正治 大宮 慎一 藤井 秀樹

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.1, pp.54-63, 2017 (Released:2016-12-31)

参考文献数

40

被引用文献数

4 5

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To investigate an effect of internal hydrogen on mechanical properties of a new austenitic stainless steel “STH2” having a nominal composition of Fe-15%Cr-9%Mn-6%Ni-2.5%Cu-0.15~0.2%N, tensile tests and fatigue crack growth tests were conducted for the specimens containing around 80 ppm hydrogen charged by the exposure in 45 MPa hydrogen gas at 300˚C for 200 h and the ones heat treated in air with the same heat pattern.At room temperature and –40˚C, no significant ductility drop by hydrogen charging was observed and about 80% of relative reduction of area was obtained, which is the same as that of JIS SUS316L with the same amount of internal hydrogen. In the specimens tensile tested at –40˚C, a small quantity of quasicleavage fracture surfaces were observed. In the banded areas in which Mn, Ni and Cu were negatively segregated, some relatively coarse voids coalesced with cracks extended along the maximum shear stress plane, which is similar to what is called void-sheet type of fracture. It is quite different from the case for tensile tests in 90 MPa hydrogen gas, in which coarse longitudinal cracks form, suggesting that the concentration of hydrogen at crack tips in 90 MPa hydrogen gas is higher than 80 ppm. It was also confirmed that fatigue crack growth rates were not accelerated by 80 ppm internal hydrogen although some faceted fracture surfaces composed of (111) γ formed.It is confirmed that STH2 has excellent properties not only in high pressure hydrogen gas but also in the circumstance of internal hydrogen of around 80 ppm.

著者

安藤 玲音 松野 崇 松田 知子 山下 典理男 横田 秀夫 後藤 健太 渡邊 育夢

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.106, no.12, pp.944-952, 2020 (Released:2020-11-30)

参考文献数

21

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Herein, we investigated the local preliminary hardening of ferrite near the ferrite–martensite interfaces in a dual-phase (DP) steel. Geometrically necessary dislocations (GNDs), generated due to interfacial misfit between different phases, may cause preliminary hardening of ferrite around such interfaces. However, for nano-hardness distribution, the hardened zone was not evidently detected by scattering measurement. Thus, we factorized nano-hardness scattering to estimate the actual ferrite hardness near ferrite–martensite interfaces.First, nano-hardness was measured around a martensite island using a conical nano-indenter in the DP steel containing 10% martensite by volume. Taking into account the scattering, the nano-hardness measurement converged to the hardness of ferrite, exceeding the distance corresponding to the nano-indenter radius. Thus, a preliminary hardening zone was not detected. Subsequently, the surface of the nano-indented microstructure was polished and observed using scanning electron microscopy (SEM) by analyzing electron back scattering diffraction (EBSD). This analysis confirmed the presence of the nano-indented microstructure under ferrite. Moreover, it established that the majority of the irregularly higher nano-hardness was caused by the buried martensite under ferrite. The value of the kernel average misorientation (KAM), which is proportional to the GND density for other irregularly higher nano-hardness points, was higher for the nano-indented microstructure as compared to that of the buried martensite. On the other hand, the ferrite was expanded under the nano-indented points for the majority of the irregularly lower nano-hardness, with some exceptions. Further, soft martensite was observed to induce irregularly lower nano-hardness locally around the interface.

著者

林 武志

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.64, no.13, pp.2037-2056, 1978-11-01 (Released:2010-02-22)

参考文献数

29

被引用文献数

2 2