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76 巻, 1 号
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坂尾 弘1990 年 76 巻 1 号 p. 17-24
発行日: 1990/01/01
公開日: 2009/06/30
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増渕 洋一, 宮本 祐三, 大住元 博1990 年 76 巻 1 号 p. 25-33
発行日: 1990/01/01
公開日: 2009/06/30
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千野 淳, 石橋 耀一, 郡司 直樹, 岩田 英夫, 鈴木 喜夫, 板垣 省三, 三谷 成康1990 年 76 巻 1 号 p. 34-41
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーThe method for estimating exposured temperature of coke by laser Raman spectrometry with multi-channel detector has been developed.
The procedure is as follows.
1) The Raman spectra of coke (1 3001 650 cm-1) are measured by a multi-channel laser Raman spectrometer.
2) The spectra are analyzed by lorentzian fitting continuously and the intensity ratio of peaks (R-value, I. 1 360 cm -1 / I. 1 580 cm-1) is calculated automatically.
3) The histogram of R-values is drawn up.
The advantage of this method compared with the powder X-ray diffraction method, which has been used until now, is as follows.
1) The sample preparation, for example, crushing, de-ashing and forming, is not needed.
2) The measuring time (3 min) is much shorter than that of the previous method (3040 min).
3) The estimating the temperature of each particle can be measured although the avarage estimating temperature of particles was measured by previous method.
This method makes it possible for the first time to estimate the exposured temperature of coke in details, for example, estimating the exposured temperature distribution of every coke particle in a certain range.抄録全体を表示PDF形式でダウンロード (871K) -
長谷川 守弘1990 年 76 巻 1 号 p. 42-49
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーA kinetic study has been made on the nitrogen desorption from inductively stirred iron-chromium melts with 6.527.5%Cr under reduced pressures at 1 600°C.
The rate of nitrogen desorption under the pressure of 8×102 Pa is essentially controlled by the mass transfer of nitrogen in liquid and gas phases as well as the chemical reaction at the liquid-gas interface, although the rate is mainly controlled by the chemical reaction at the interface.
In case of 17%Cr melt containing 50 ppm of oxygen at around 70 ppm of nitrogen in the melt under the pressure of 8×102 Pa, the interfacial resistance is 5 times larger than the resistance of mass transfer in the liquid phase, and the interfacial resistance is 10 times larger than that in the gas phase.
It is suggested that the apparent adsorption coefficients of O and S increase with increase of Cr content in the melt.抄録全体を表示PDF形式でダウンロード (971K) -
橋本 俊一, 薬師 寺輝敏, 前田 恭志1990 年 76 巻 1 号 p. 50-56
発行日: 1990/01/01
公開日: 2010/02/16
ジャーナル フリーThe effect of metallurgical factors on the γ-value of cold rolled steel sheet has been reported by many researchers. However the number of reports with regard to the mechanical factors on the γ-value is quite few. In this study, the effects of roll diameter, thickness of the steel and reduction per pass on the γ-value of extra low carbon cold rolled steel sheet has been examined and discussed using the results obtained by rigid finite element method.
(1) γ-value of cold rolled and annealed steel sheet increases with increase in roll diameter and decrease in initial thickness at the cold rolling.
(2) When the changes in thickness and reduction per pass during continuous cold rolling are considered, γ-value shows a good relationship with the sum of {Roll diameter (Di) / Thickness (tmi)} and cold reduction of each pass.
(3) The decrease in γ-value with decrese in {Roll diameter (D) / Initial thickness (to)} relates with the increase in shear strain in the surface region of the sheet. That is, the deterioration of γ-value with decrease in this parameter is brought about by formation of the unfavorable texture in surface region for deep drawability originated by shear strain.抄録全体を表示PDF形式でダウンロード (774K) -
安斎 正博, 中川 威雄1990 年 76 巻 1 号 p. 57-64
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーIn generally, particle composite alloy is fabricated by powder metallurgy. The other hand, Plasma Powder Melting (PPM) method is being put into practice for welding machine in the field of surface hardening. In this study, it is attempted to fabricate Fe-carbide composite materials using PPM method. The Fe powder, Cr3C2 powder, NbC powder and WC powder are mixed respectively, which are directly melted by plasma arc in the graphite mold so as to obtain Fe-carbides composite materials. The maximum bending strength of the composite reinforced with 20wt% of Cr3C2 particles was 1.2 GPa, and the strength value was remarkably high in comparison with 0.8 GPa of the product without reinforcing under similar preparation conditions. In Fe-NbC composites, the maximum bending strength of the composite reinforced with 20wt% of NbC particles was 0.98 GPa, NbC particles were dispersed uniformly. In Fe-WC composites, the strength value of this composites remarkably low in comparison with other Fe-carbide composites, which was caused by difference of density between Fe and WC. In generally, with increasing the content of carbide, the bending modulus of these composites decreased monotonously and hardness of these increased monotonously.抄録全体を表示PDF形式でダウンロード (5631K) -
今井 義一, 田中 義和, 市川 宏, 石川 敏功1990 年 76 巻 1 号 p. 65-72
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーRecently, SiC fiber from polycarbosilane (SiCpcs) reinforced pure Al "proform wires" with high tensile strength have been developed by means of the continuous liquid metal infiltration method.
In this paper, using this method compatibilities of the fiber and various Al alloys as the matrices were investigated. The matrices used were Al based binary alloys contained each 5wt% of Si, Cu and Mg, and practical Al alloys such as A2024, A5052, A6061 and A7075. No wire with high strength was obtained in any matrix.
The results observed were precipitation of crystal Si on the surface of the SiC fiber in Al-5Si, Al-CuAl2 eutectic crystals coupling fibers in Al-5Cu, and diffusion layer of Mg into the fiber in Al-5Mg. They were considered to be the reasons of degradation of wire tensile strength. And also in the case of practical Al alloys similar tendencies were recognized.
From the experimental results, A1-3Cu-2Ni alloy was originally designed, and contact time of fiber and molten matrix during the infiltration were shortened. The tensile strength of the wire obtained was about 1.0GPa (at Vf 0.4) near the wire strength of pure Al matrix.
Consequently, it is concluded that compatibilities of SiCpcs fiber and Al alloys could be improved by adopting optimum processing variables and alloy compositions.抄録全体を表示PDF形式でダウンロード (11775K) -
金築 裕, 勝亦 正昭, 井上 毅1990 年 76 巻 1 号 p. 73-80
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーIn the process of making structural parts, spheroidization treatment of the rolled bars is applied to obtain good cold forgeability. In this study, the effect of using controlled rolling and cooling process on the subsequent spheroidization behavior of medium carbon steel was investigated using a hot deformation simulater and transmission electron microscope.
The following results were obtained.
(1) By controlling the cooling rate to 10°C/s immediately after controlled rolling, the post dynamically recrystallized fine austenite grains did not grow and transformed to a fine and globular ferrite-pearlite microstructure. This microstructure revealed an extremely high volume fraction of ferrite compared with a microstructure transformed from coarse austenite grains.
(2) By using transmission electron microscope, fine ferrite-pearlite microstructure transformed from fine dynamic-recrystallized austenite grain was observed. It was found that the extrinsic grain boundary dislocations were inherited from residual strain due to rapid cooling during the post dynamic recrystallization state. Furthermore, cementite films, which suggest an enhanced diffusion of carbon along the nonequilibrium boundary structure, were formed along each phase boundary.
The discussion is also made about the enhanced spheroidization during intercritical annealing on the basis of the behavior of grain boundary dislocations during reheating.抄録全体を表示PDF形式でダウンロード (9031K) -
立野 一郎1990 年 76 巻 1 号 p. 81-88
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーA quantitative method for deriving the anisotropy in the magnetic induction from the texture data of electrical steel sheets was developed. Using the data of the three dimensional texture analysis by the vector method, magnetic induction parameter BT for any direction in the steel sheet plane was formulated, under the assumptions of (1) each grain is magnetized in one of the easy magnetization directions having a smallest angle from the direction of the applied field, and (2) interaction between neighbouring grains is negligible.
Comparing BT calculated from the data of the three dimensional texture analysis by the vector method with observed B50/BS, it was confirmed that the two agreed well in three kinds of non-oriented electrical steel sheets. By an observation of magnetic domains by SEM, it was revealed that the assumption for the calculation of BT that each grains had no domain walls in themselves was realized in the vicinity of B50. This was the reason for the agreement of calculated BT with observed B50/BS.抄録全体を表示PDF形式でダウンロード (2670K) -
鹿内 伸夫, 香川 裕之, 栗原 正好, 田川 寿俊1990 年 76 巻 1 号 p. 89-96
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーThe heavy-gauge HSLA steel plates with low yield ratio have been applied to the steel-frames of high-rise buildings to utilize the benefits of their high strength and uniform deformability. The yielding behavior of steels relates to the microstructural morphologies such as microstructure, volume fraction and shape of each phase, dislocation, grain size and so on. In the present paper, appropriate microstructural morphology for low YR HSLA steel was investigated by FEM analysis. The influence of shape, volume fraction and mechanical properties of each phase on yielding behavior were analyzed by dual-phase and tri-phase models. From a series of FEM analysis, it is clarified that the appropriate microstructural morphologies to decrease the YRare as follows. (1) Uniform distribution of spherical high-hardness phase in low-hardness phase (2) Around 50% volume fraction of low-hardness phase (3) Increase of the ratio of yield strength of high-hardness phase to that of low-hardness phase.抄録全体を表示PDF形式でダウンロード (940K) -
鎌田 芳彦, 大谷 泰夫1990 年 76 巻 1 号 p. 97-104
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーHot cracking of Nb containing steels (Nb steel) during HCR (Hot Charge Rolling) process has been investigated by means of laboratory rolling simulation using small ingots and conducting the hot tensile tests simulated HCR process.
Hot cracking in Nb containing steels occurs in the case of HCR process with the charging temperature ranging from 650°C to 900°C. This phenomenon can be explained by the precipitation of Nb (CN) at the large austenite grain boundaries succeeded from solidification at the interval of casting process and heating process before rolling. The precipitation of Nb (CN) at such a large austenite grain boundary during rolling process leads to larger strain concentration and promotes the initiation of microvoids due to decohesion of the grain boundary precipitates from the matrix. Final fracture mode is ductile intergranular fracture of austenite by microvoid coalescence.
To avoid the hot cracking in Nb containing steels during HCR process, it is favourable to chose the charging temperatures out of above mentioned temperature region. But, even if cast slabs are charged to furnace with such temperature, hot cracking in Nb containing steels can be avoided by controlling the heating temperature before rolling higher than solution temperature of Nb (CN).抄録全体を表示PDF形式でダウンロード (10668K) -
山本 重中, 中島 宏興1990 年 76 巻 1 号 p. 105-112
発行日: 1990/01/01
公開日: 2010/02/16
ジャーナル フリーMachinability of a bearing steel of which hardness was changed in a wide range by quenching and tempering was investigated. Sawing, drilling and turning were carried out for work materials of the hardness of HV180-770 and cutting time, thrust force and resultant cutting force were measured respectively.
1) In all machining methods the minimum cutting resistance (cutting time) was observed at the hardness of about HV350. Multiple regression analysis was applied between the above measuring values and the mechanical properties of work materials. The regression equation indicates that the cutting resistance increases with increase of the tensile strength, hardness, the elongation and reduction of area.
2) It was suggested that the minimum in the cutting resistance at the hardness of_??_HV 350 was brought about by the formation of the strong built-up edge. The cutting resistance increased in the hardness range of HV180-250 and 430-550. The former is due to an enlargement of the chip shear region and the latter to an increase of the deformation resistance per unit area of the chip shear region.
3) Sawtooth like chips were produced, when work materials of the hardness of HV550-700 were machined at high speed. The mechanism is considered that the chip shear region is subjected to the shear deformation by softening arising from the concentrated generation of heat.抄録全体を表示PDF形式でダウンロード (3260K) -
田中 學, 飯塚 博, 葦原 文夫1990 年 76 巻 1 号 p. 113-119
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーEffect of serrated grain boundaries on the creep-rupture properties of a wrought cobalt-base HS-21 alloy are investigated in the temperature range from 1 089 K (816°C) to 1 311 K (1 038°C). The strengthening mechanism of serrated grain boundaries is then discussed based on the authors' grain-boundary fracture model, in which the recovery effect by diffusion of atoms is taken into account. Specimens with serrated grain boundaries showed higher creep-rupture strength and larger rupture ductility than those with normal straight grain boundaries. Especially, large difference in the rupture ductility occurred at the lower temperatures. A ductile grain-boundary fracture was observed on the specimens with serrated grain boundaries, but typical grain boundary facets were found in specimens with straight grain boundaries, except high-temperature low-stress conditions. The results of the theoretical discussions based on the model suggested that the strengthening effect of serrated grain boundaries is correlated to the change in the creep-fracture mechanism of specimens with the creep-rupture test conditions.抄録全体を表示PDF形式でダウンロード (7570K) -
金築 裕1990 年 76 巻 1 号 p. 120-127
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーThe grain boundary cementite and widmanstatten cementite consisted in a hypereutectoid steel have been considered to cause the brittle fracture. In this study, the effect of Co addition on the transformation behavior of the hypereutectoid steel has been examined in order to control the grain boundary cementite precipitation. It was found that in the case of hypereutectoid steels containing carbon content less than 1.3 wt% the grain boundary cementite precipitation could be suppressed with the addition of Co and patenting treatment.
By suppression of grain boundary cementite, the hypereutectoid steel showed good drawability comparable with that of eutectoid steel and the increase of tensile strength comparing with eutectoid steel. The analysis using EMBURY-FISHER relation showed the increase of workhardening rate due to the refinement of lamellar spacing, which was confirmed by microstructural observation. The effect of Co addition on the transformation behavior was also discussed from CCT curves.抄録全体を表示PDF形式でダウンロード (2856K) -
高橋 礼二郎, 白 瀾1990 年 76 巻 1 号 p. 128-131
発行日: 1990/01/01
公開日: 2009/06/30
ジャーナル フリーPDF形式でダウンロード (2199K)
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