著者

作井 誠太 中村 正久 布村 成具

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.48, no.1, pp.28-34, 1962-01-01 (Released:2010-02-22)

参考文献数

7

被引用文献数

4 1

---

This paper describes of the influences of deformation rate of wide range on the tensile impact properties of several steels by using a high-speed impact-tensile testing machine with a large rotary disk. The deformation rate was varied from static region to 80m/s, and the testing temperature from room temperature to 800°C. The results obtained were summarized as follows:(1) Blue brittleness was observed clearly in mild steel and two alloy steels, and temperature range of blue brittleness shifted to higher temperature with increasing rate of deformation. This shift was conspiquous up to a speed of deformation of 10m/s, but was decreased beyond this speed. Moreover, at the speed of 40m/s the blue brittleness temperature was decreased on the contrary.(2) The similar dependence on deformation rate was also made clear, with regard to the brittleness of 18-8 stainless steel which was due to the effect similar to that causing blue brittleness as well as the brittleness of pure copper at elevated temperature.(3) At higher temperature over 600°C, the critical impact velocity was not observed so distinctly as obtained at room temperature. Tensile strength was lowered with a larger scattering as the deformation rate was increased, while, correspondingly, the value of elongation or reduction of area showed tendency to be rather larger. This phenomenon, named by the authors as “high-rate deformation softening”, was discussed in relation to the loadtime curves observed experimentally.

著者

Manabu Takahashi

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.55, no.1, pp.79-88, 2015-01-15 (Released:2015-02-06)

参考文献数

74

被引用文献数

24 40

---

Development in sheet steels has progressed in strong relation with automotive industry in Japan. To meet the requirements from automotive industry, various types of sheet steels including high and ultra high strength steel sheets have been developed. Progresses in three types of steel series will be discussed by checking the historical facts and technologies and their contributions. Introductions of interstitial free (IF) steel and continuous annealing system are the important events in mild steel developments for panels. Extensive work on finding the optimum mixtures of hard and soft phases to improve elongation of steels contributed to improve the crashworthiness of autobodies. Continuous annealing system also played an important role in producing these advanced high strength steels. Precipitation is used in a particular way which is to scavenge solute carbon and nitrogen and to prevent coarse cementite particle precipitation. It is also worth to point out that the collaborative activities particularly strong in Japan between steel manufacturers and auto companies have affected the progress in advanced sheet steels.

著者

山尾 文孝 佐々 健介 岩井 一彦 浅井 滋生

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.1, pp.30-35, 1997-01-01 (Released:2009-06-19)

参考文献数

11

被引用文献数

33 41

---

The principle on separating inclusions in a molten metal by using a fixed alternating magnetic field has been confirmed through experiments with molten aluminium. The separating efficiency of inclusions is studied through experimental and analytical ways under different operating conditions. The mathematical model to predict the separating efficiency is developed and the efficiencies predicted by the model are compared with the experimental ones.A feasibility study on the application of an electromagnetic inclusion separation in a molten steel is performed. An operating non-dimensional parameter, Y ≡(ρfdp2Be2LtS) (μfμeWdt2) which characterizes an electromagnetic inclusion separation process is newly proposed.

著者

佐藤 忠雄

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.43, no.7, pp.745-748, 1957-07-01 (Released:2009-05-26)

参考文献数

5

被引用文献数

1

---

Recently the heat resisting alloys have made remarkable developments. There are few differences in the essential consideration of chemical constituents, but the aging time has been so prolonged that the stability of structure and strength at elevated temperature much increased. In heat-resisting alloys, some phenomena such as creep and fatigue take place under repeated stresses during practical use.The transformation and precipitation of the alloys are accelerated by these repeated stresses so that there occurs a change of the volume and a decrease in the creep or the fatigue strength.Further, a systematic research on these problems is needed. It is also presumed neccessary that new manufacturing techniques, for example, vacuum-melting, vacuum-casting and hotextrusion should be introduced for further improvements in heat resisting alloys.

著者

武田 喜三

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.14, pp.2239-2246, 1978-12-01 (Released:2010-02-22)

被引用文献数

1

著者

小野寺 龍太 森川 龍哉 上木原 竜太

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.87, no.1, pp.63-69, 2001-01-01 (Released:2009-06-19)

参考文献数

7

被引用文献数

1 1

---

The yield point phenomena in low carbon steel have been explained by the Cottrell or the Johnston-Gilman theory in terms of microscopic variables such as dislocation density, dislocation velocity and the interaction energy between dislocation and solute atom. However, the lower yield stress and the amount of the Lüders strain (stretcher strain) seems not to have been predicted by the above theories. In the present work we tried to explain the phenomena quantitatively by a phenomenological (rheological) model using macroscopic variables such as work-hardening rate and the strain rate sensitivity of flow stress which we can be measured by tensile test. In the model a new internal stress was introduced which is supposed to be work (strain)-softened and age-hardened. Numerical calculation showed that the model can predict the values of the upper and lower yield stress and the amount of the Lüders strain, and the effect of strain rate on these characteristics.

著者

藤井 哲雄

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.10, pp.1398-1411, 1976-09-01 (Released:2010-02-22)

参考文献数

14

被引用文献数

1 1

著者

森本 忠興

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.57, no.1, pp.116-124, 1971-01-01 (Released:2012-02-20)

参考文献数

14

---

The strength and toughness of a low alloy steel (0.8% carbon), quenched from 850°C and tempered at various temperatures below 600°C, have been investigated by static and dynamic bend tests and static torsion tests. The effect of notch radius on bend properties has also been studied. The results obtained in this study are summarized as follows:(1) The plastic deflection in the static bend test or the impact value decreases exponentially with increasing the stress-concentration factor “α” at the notch root.(2) The appearance of low temperature temper brittleness is markedly affected by test methods, that is, it appears at relatively low tempering temperatures and the embrittlement is more clearly observed in unnotched dynamic bend or static torsion tests than in static notched and unnotched bend tests.(3) An optimum hardness is observed on the fracture strength versus hardness curve in both bend and torsion tests.

著者

Nobuo Nakada Norimitsu Koga Yuki Tanaka Toshihiro Tsuchiyama Setsuo Takaki Masaharu Ueda

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.55, no.9, pp.2036-2038, 2015-09-15 (Released:2015-09-29)

参考文献数

17

被引用文献数

13 18

---

The strength of pearlitic steel was clearly reduced by annealing, even though cementite stably maintained a lamellar structure. In response, lattice strain of the ferrite phase in pearlite monotonically decreased with increasing annealing time. As a result, a good linear relationship was established between the strength and ferrite lattice strain independent of the interlamellar spacing and morphology of cementite. This suggests that the ferrite/cementite elastic misfit strain contributes to the high strength of pearlitic steel.

著者

河合 正吉

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.14, pp.1919-1932, 1961-12-01 (Released:2010-10-12)

参考文献数

16

著者

利岡 靖継 雑賀 喜規 栗山 良員

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.54, no.4, pp.416-426, 1968-03-01 (Released:2010-10-12)

参考文献数

17

被引用文献数

2 2

---

A simple method is proposed to predict mechanical properties of heattreated large steel forgings. The method is based on the findings. Firstly, the main considerations for the strength and the ductility are the carbon content of the forging and the microstructures induced during quenching. Secondarily, the microstructures can be computed from available CCT diagrams and cooling rates of quenching in the temperature range of 600°C to 300°C. These findings are verified experimentally on carbon steels and lowalloyed steels containing such elements as Ni, Cr and/or Mo. Equations for the rapid estimates of the cooling rates of steel forgings of the maximum diameter of 1000mm are derived experimentally as follows:log D+0.513 log C=2.37 when quenched in waterlog D+0.699 log C=2.02 oillog D+0.954 log C=1.18 airwhere, D is the diameter of a steel forging in mm. and C the looling rate in the temperature range of 600°C to 300°C in °C/sec.Discussions are given on the validities of the findings and the equations.

著者

梅本 実 田村 今男

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.68, no.3, pp.383-392, 1982-03-01 (Released:2009-06-19)

参考文献数

42

被引用文献数

4 4

著者

郡司 好喜

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.80, no.4, pp.N176-N186, 1994-04-01 (Released:2009-06-19)

参考文献数

36

被引用文献数

3 3

著者

杉本 孝一

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.60, no.14, pp.2203-2220, 1974-12-01 (Released:2010-10-12)

参考文献数

53

被引用文献数

19 17

著者

福井 彰一

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.55, no.2, pp.151-161, 1969-02-01 (Released:2010-10-12)

参考文献数

13

被引用文献数

16 10

---

The influence of tempering on the delayed fracture characteristics in 0.1N HCl solution, the initiationand propagation behavior of cracks in delayed fracture and the hydrogen embrittlement characteristics in-tensile tests have been studied in metallurgical view point for several low-alloy steels with the difference in, carbon content and tempering behavior.In general, the delayed fracture strength ratio (fracture strength at 30hr in life divided by static strength)-varied depending on the hardness of the steel, and showed almost constant value of 0.85 in all steels with thehardness up to Hv 350 and rapidly decreased the value with increase in hardness above Hv 350.Contradictorily to the general aspects described above, an abnormal increase appeared in the delayed.fracture strength ratio for the steel tempered at about 250°C, independently on the hardness of the steel.This phenomenon shifted to the higher tempering temperature as silicon content in the steel was increased.Considering the stabilizing effect of silicon on epsilon carbides, it is supposed that the phenomenon is attributedto the precipitation of epsilon carbides.The cracks in delayed fracture initiated at the prior austenite grain boundaries, but the propagation pathdiffered according as the tempering condition of the steel. It has been observed that the cracks propagatedat the prior austenite grain boundaries in the steels tempered in the temperature range of primary temper-brittleness (500°F embrittlement), and mainly propagated across the interior of the grains the steelstempered in the temperature out of the range of primary temper-brittleness.From the results of the electron microscopic observation of the precipitation behavior of carbides, ithas been observed that cementites precipitated in a line at the prior austenite grain boundaries in the specimenof which crack in delayed fracture propagated along the grain boundaries. The delayed fracturestrength of these steels were inferior to those cracks propagated across the interior of the grains.The dependence of the degree of hydrogen embrittlement, which was indicated as the decrease of the reductionof area in tensile test for the steel dipped in 0.1N HCl solution, on the tempering temperature was in goodagreement with that of the delayed fracture strength in the same solution. This fact suggests that themicrostructure of the steel contributed in the same way to both of the delayed fracture strength and the hydrogen embrittlement.

著者

杉本 克久

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.70, no.7, pp.637-649, 1984-05-01 (Released:2009-06-30)

参考文献数

56

被引用文献数

14 6

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

Xianfeng Hu Lena Sundqvist Ökvist Elin Åström Fredrik Forsberg Paolo Checchia Germano Bonomi Irene Calliari Piero Calvini Antonietta Donzella Eros Faraci Franco Gonella Joel Klinger Davide Pagano Andrea Rigoni Pietro Zanuttigh Paolo Ronchese Michele Urbani Sara Vanini Aldo Zenoni Gianni Zumerle

出版者

The Iron and Steel Institute of Japan

雑誌

ISIJ International (ISSN:09151559)

巻号頁・発行日

vol.58, no.1, pp.35-42, 2018-01-15 (Released:2018-01-17)

参考文献数

17

被引用文献数

3 7

---

Knowing the distribution of the materials in the blast furnace (BF) is believed to be of great interest for BF operation and process optimization. In this paper calibration samples (ferrous pellets and coke) and samples from LKAB’s experimental blast furnace (probe samples, excavation samples and core-drilling samples) were measured by the muon scattering tomography detector to explore the capability of using the muon scattering tomography to image the components in the blast furnace. The experimental results show that it is possible to use this technique to discriminate the ferrous pellets from the coke and it is also shown that the measured linear scattering densities (LSD) linearly correlate with the bulk densities of the measured materials. By applying the Stovall’s model a correlation among the LSD values, the bulk densities and the components of the materials in the probe samples and excavation samples was established. The theoretical analysis indicates that it is potential to use the present muon scattering tomography technique to image the components in various zones of the blast furnace.

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

---

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。