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76 巻, 3 号
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小野寺 秀博, 山崎 道夫1990 年 76 巻 3 号 p. 307-313
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーPDF形式でダウンロード (836K) -
武子 康平1990 年 76 巻 3 号 p. 314-319
発行日: 1990/03/01
公開日: 2010/02/16
ジャーナル フリーPDF形式でダウンロード (799K) -
亀本 喬司1990 年 76 巻 3 号 p. 320-328
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリー流れの中に渦が発生するメカニズムは,流れの初期条件や境界条件によってかなり相違があるが,本質的には渦度がどのように供給され,それらがどのように流れるかによっていることは本文に説明したとおりである. 自然界における空気や水の流れを見ても,渦を伴わないものはほとんど無いと言っても過言ではない.技術の粋を集めて作られた航空機でもひとたび設計条件からはずれると,Fig.7に示したような流れの剥離により失速状態に陥ることもあり,渦とはこれほど発生しやすいものと考えたほうが良さそうである.
流れにおける渦の生成を,さまざまな条件下で意のままにコントロールできたとすれば,それは正に人間にとって夢の実現に値するものである.鳥や魚のように,渦無しの流れと渦放出を巧みに使い分けることもできるし,台風やたつ巻の,発生や進路を自由に制御することもできるようになる.
流れにおける渦の生成に関する研究を行っていると,流体が時として生き物のように感じられ,「流れは, 自身の姿を自由に変え,常に流れやすいように流れている」ように見えてくる.要は,「流れの気持ち」が理解できるようになることであろうか.溶けた鉄の流れがどのような性質を持つ生き物なのかについては,ご専門の技術者や研究者の方々が解き明かしてくださるものと楽しみにしている.この分野の方々にとって,本文が多少なりともご参考になれば幸いである.抄録全体を表示PDF形式でダウンロード (3833K) -
菅野 道夫1990 年 76 巻 3 号 p. 329-336
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーPDF形式でダウンロード (1089K) -
丹羽 康夫, 炭竃 隆志, 牧 章, 長野 誠規, 酒井 敦, 桜井 雅昭1990 年 76 巻 3 号 p. 337-344
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーIn order to standardize the coke properties necessary in the blast furnace and to establish the control technologies of hot metal components by clarifying the changes in characteristics of coke and behaviors of hot metal and slag at the lower part of the blast furnace, a sampler, which is able to sample in-furnace molten materials at the tuyere level during the outage (for regular inspection and maintenance), was installed at No. 2BF (Inner volume of 2 828 m3, hearth diameter of 11.5 m) in Fukuyama Works.
The following results were obtained ;
(1) The coke temperature of the raceway is influenced by not only the theoretical flame temperature calculated by Ramm's equation but also the distribution of burden and gas flow.
(2) In the vicinity of the raceway, the higher the Coke Reaction Index (CRI) is, the more the coke size decreases, and the average disintegrated rate at the lower part of a blast furnace will be increased accordingly.
(3) Silicon content in the dropping zone depends upon the temperature and is affected by CRI.
(4) A presumed equation of a static hold-up (hs) can be obtained as follows :
hs=0.20·Gam0.102·Cpm-0.387
where Gam : Modified galilei No., Cpm : Modified capillary No.抄録全体を表示PDF形式でダウンロード (914K) -
石橋 一弘, 柘植 俊一1990 年 76 巻 3 号 p. 345-351
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーThe Direct Reductive Heating (DRH) was great practical advantage in continuous heating of thin steel plates compared with the conventional indirect heating conducted under nitrogen environment.DRH has been so far employed experimentally with some success at the level of know-hows.However, its theoretical background has not been given as to what aerothermochemical conditions necessary for reduction at a steel surface to be realized.An computational approach for the 2-D flame held in the boundary layer of a steel surface shows some evidence of DRH judging from the concentration profiles of chemical species.In fact, the ratio of CO2 /CO the most crucial measure for the reduction goes down to less than 0.1 on the surface just behind the flame foot, for a narrow wall temperature range around 900°C.It is concluded thereby that a fuel-rich hydrocarbon-air mixture can generate a reductive region behind the flame front where the oxygen is depleted if the cooling effect due to the wall is favorable for formation of more CO rather than CO2.抄録全体を表示PDF形式でダウンロード (848K) -
原 徹, 月橋 文孝, 佐野 信雄1990 年 76 巻 3 号 p. 352-359
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーThe phosphorus partition between BaO-BaF2 fluxes and Fe-Cr-Csatd. alloys was measured at temperatures ranging from 1 175°C to 1 300°C under a CO atmosphere.
The phosphorus partition ratio increases with increasing BaO content in the fluxes and decreases with increasing chromium content in Fe-Cr-Csatd. alloys. The BaO-BaF2 system was found to have a large phosphate capacity ranging from 1026 to 1028.5 at 1300°C, which is much larger than that for the CaO-CaF2 system. The enthalpy change for the dephosphorization reaction by BaO bearing fluxes was determined to be-528 kJ/mol. The chromium partition ratio increases with an increase in BaO content especially in the higher BaO content range. The possibility of the removal of phosphorus from Fe-16% Cr-C alloys without much oxidation loss of chromium by using 50% BaO-50% BaF2 flux was demonstrated.
Furthermore, the activity of BaO for the BaO-BaF2 system was determined at 1 200°C and 1 300°C and the activity of BaF2 was calculated by using the Gibbs-Duhem relationship. The phase diagram for the BaO-BaF2 system was also discussed.抄録全体を表示PDF形式でダウンロード (1037K) -
原 茂太, 荻野 和巳1990 年 76 巻 3 号 p. 360-367
発行日: 1990/03/01
公開日: 2010/02/16
ジャーナル フリーThe rate of FeO reduction in molten FeO-CaO-SiO2 slags by graphite is determined by measuring volumes of gas evolved in a temperature range of 12501400°C. An X-ray fluoroscopy technique is applied to visualize the appearance of the reaction. The results are summarized as follows ; (1) formation of foaming layer, which is observed above the dense slag melt after slag-graphite contact, has an incubation period, (2) the rate of the gas evolution becomes maximum when the foaming layer appears (3) the foaming layer as well as the dense slag melt contributes to the FeO reduction and (4) the rate of the FeO reduction strongly depends on activity of FeO in the melt, but the dependency changes when the activity is above 0.8.抄録全体を表示PDF形式でダウンロード (1126K) -
藤澤 敏治, 山内 睦文, 坂尾 弘1990 年 76 巻 3 号 p. 368-375
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーExperimental study was conducted on the equilibrium between molten Fe-Al-S alloys and CaO-Al2O3-CaS slags in a CaS crucible at 1 873 K. The equilibrium relation could be represented by the following reaction :
3CaO(s)+2Al+3S=3CaS(s)+Al2O3(s)
By application of the Gibbs-Duhem equation, integration techniques were developed which allowed us to calculate the activities of CaO and Al2O3 from the slag composition and the activities of aluminum and sulfur in the alloy. The free energy of the above reaction was also determined as well as the free energies of formation of calcium aluminate compounds, CaO·Al2O3(CA), CaO·2Al2O3(CA2), and CaO·6Al2O3(CA6)from their constituent oxides.抄録全体を表示PDF形式でダウンロード (987K) -
中田 等, 安中 弘行1990 年 76 巻 3 号 p. 376-382
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーThe influence of manganese and sulfur contents of steel on its hot ductility just below solidus temperature which has close relation to the internal crack was investigated using a hot tensile testing machine.The shape and composition of sulfide were also examined in relation to the hot ductility of steel. In order to evaluate the hot ductility of steels below solidus temperature, two parameters were introduced, the first being Z.D.T. (Zero Ductility Temperature) and the second recovery ratio of reduction area. These two parameters have close relation to Mn3/S, where Mn and S are manganese and sulfer contents (wt%) in steel, respectively. In the steel whose Mn3/S is less than 1.5, the recovery state of ductility below solidus temperature changes for the worse abruptly, and hence internal crack was considered to occur easily.抄録全体を表示PDF形式でダウンロード (4374K) -
甲田 満, 内田 幸夫, 鈴木 勝, 出口 武典, 広瀬 祐輔1990 年 76 巻 3 号 p. 383-390
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーAn inhibition mechanism of the black patina development on the surface of 4% Al-0.1% Mg-Zn alloy coated steel sheet by spraying aqueous solution of Co salt was investigated with various surface analytical methods.
Without Co treatment, the coating surface rapidly changed its color into black in a high temperature and high humidity environment. This phenomenon was due to the formation of thick oxide film which composed of Zn, Cr and Al. The blackening of the coating surface was effectively retarded by spraying aqueous solution of Co salt onto the molten coating surface just after hot dipping.
On the Co treated coating surface, a large number of Co3O4 deposits, of which structure was identified with HEED, were observed in TEM image and in IMA ion image. The thickness of this Co oxide was 0.1 0.2 μm as determined by a direct TEM observation of the ultramicrotomed cross section of the coating layer. SAM and ESCA depth-profiles showed that Co oxide retarded oxidation of the coating surface. This effect of Co oxide was attributed to cathodic inhibitive action or stable zinc hydroxide forming ability of Co ion which was eluted into the condensed water on the coating surface.抄録全体を表示PDF形式でダウンロード (5147K) -
今井 義一, 田中 義和, 市川 宏, 石川 敏功1990 年 76 巻 3 号 p. 391-398
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーPolymer derived SiC fiber reinforced Al "preform wires" were used as semi-finished materials for fabricating composites by hot-pressing. The influence of combination of pressure, heating temperature and holding time during hot-pressing on strength, microstructure and fracture surface of fabricated composites was investigated.
Pressure below 30 MPa and pressing time shorter than 300 s were not enough to bond preform wires each other. Pressing time longer than 1.8 ks degradated fiber strength. The combination of pressure of 40 MPa or more and pressing time of 600 s through 1.2 ks resulted in high strength of composites. Under such conditions, pressing temperature below 788 K was too low to bond preform wires each other, while pressing temperature above 833 K lead to fiber damage due to interfacial reaction between SiC fibers and aluminum matrix.
Consequently, the pressing temperature from 803 K through 823 K was suitable to make high strength composites. The composites fabricated under the conditions described above showed very high tensile strength, which was about 95 pct of that of the preform wires.
It can be concluded that metal matrix composites can be easily fablicated using preform wires as semifinished materials.抄録全体を表示PDF形式でダウンロード (7932K) -
安斎 正博, 中川 威雄1990 年 76 巻 3 号 p. 399-405
発行日: 1990/03/01
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 hardning. In this study, it is attempted to fabricate Co alloy (KCM-1)-carbide composite materials and 3-dimensional model using PPM method. The KCM-1 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 KCM-1-carbide composite materials.
The maximum bending strength of the composites reinforced with 20 wt% of Cr3C2 particles was 1.18 GPa, and the strength value was low in comparison with 1.34 GPa of the product without reinforcing under similar preparation conditions. In KCM-1-NbC composites, the maximum bending strength of the composite reinforced with 20 wt% of NbC particles was 1.07 GPa, NbC particles were dispersed uniformly. In KCM-1-WC composites, the strength value of this composites remarkably low in comparison with other KCM-1-carbide composites, which was caused by difference of density between KCM-1 and WC. With increasing the content of carbide, the bending modulus of these composites decreased monotonously, and the hardness of these composites increased monotonously. It has succeed in making 3-dimensional model of KCM-1-carbide composite using PPM apparatus. Plasma powder melting method will be used practically in the field of manufacturing of mold or mock up.抄録全体を表示PDF形式でダウンロード (6243K) -
中川 師夫, 祖父江 昌久, 田口 三夫1990 年 76 巻 3 号 p. 406-413
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーSteel rolls have been predominantly adopted for cold rolling of thin strip. They, however, appear to be approaching the limit of rolling performance.
To provide rolls with performance levels that steel can never attain, the use of ceramics has been studied, because ceramics generally possess higher hardness, larger Young's modulus than those of steel and a nonadhesion property to rolled strip, etc.
In this work, sialon ceramic was selected and its characteristics and performance in cold rolling were examined.
Results obtained were as follows:
(1) The rolling fatigue strength was higher than 2.8 GPa.
(2) 25% thinner gage under 9% lighter load was obtained in rolling mild steel.
(3) 30% glossier rolled surface was obtained in rolling stainless steel.抄録全体を表示PDF形式でダウンロード (2094K) -
水井 正也, 武智 弘, 関根 知雄1990 年 76 巻 3 号 p. 414-421
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーLow cycle fatigue damage of two types of formable hot-rolled high strength sheet steels for automobile use with different static strengthening mechanisms of 600 MPa class in tensile strength; 0.9% Si-1.2% Mn dual phase and 0.04% Nb added precipitation hardened steel was studied by the X-ray differaction, SEM and TEM methods, the following results were obtained.
(1) Si-Mn dual phase steel (DP) with low yield ratio shows higher cyclic stress than Nb containing precipitation hardened steel with high yield to tensile strength ratio.
(2) Nb containing steel shows monotonuous cyclic softening which provides a decrease in the X-ray half value breadth resulting from sub-boundaries due to the rearrangement of dislocations.
(3) DP steel offers initial cyclic hardening followed by cyclic softening with an initial increase followed by a decrease in the X-ray half value breadth, this resulting from fine cell-structures in the ferrite matrix.
(4) DP steel seems to show high resistance to a fatal crack due to the effect of microstructures of soft ferrite and fine martensite.抄録全体を表示PDF形式でダウンロード (5815K) -
岡本 篤樹, 水井 直光1990 年 76 巻 3 号 p. 422-429
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーThe textures and precipitates formed in ultra low carbon Ti-added sheet steels containing varied amounts of Mn, P and Nb, by processing through cold rolling and continuous annealing, have been investigated for the development of a high strength sheet steel with a high r-value. A Ti-added steel alloyed with 1.4%Mn and 0.08% P has been found to meet the required mechanical properties. In the steels containing both Ti and P, the recrystallization texture showed a characteristic heating rate dependence ; that is, the faster the heating rate for annealing, the stronger the {111} texture components after recrystallization. FeTiP pre-cipitates were observed in the annealed steels but not in the hot rolled steels. An increase of Mn content suppressed the precipitation of Ti sulphide precipitates (TiS and Ti4C2S2) in the hot rolled steel, by form-ing MnS precipitates, and influenced the FeTiP precipitation. It was thought that the precipitation of FeTiP during the recrystallization stage influenced the texture development. The roles of Mn, P and Ti in the recrystallization texture control through the formation of fine FeTiP precipitates were discussed.抄録全体を表示PDF形式でダウンロード (5212K) -
勝亦 正昭, 高木 勇, 梶 晴男1990 年 76 巻 3 号 p. 430-437
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーThe effect of overheating on the amount of MnS(Vs) and the number of MnS(n) precipitated on unit area of ductile intergranular facets and hence on the change in upper shelf energy (vEs) was investigated in this study. The vEs decreased proportionally with an increase in Vs in steels overheated by isothermal holding. A change in vEs related to both Vs and n in steels overheated by continous cooling. The increase in vEs due to slow cooling at a cooling rate less than 2°C/min was caused by an decrease in n; despite an adequate amount of Vs. The Vs was 0.1 to 0.5 times as small as the amount of MnS precipitated on unit area of grain boundaries (Vs') which was calculated from the Mn/S solubility product and grain boundary area per unit volume. The Vs/Vs' tended to decrease when S content increased. This suggests that the increase in S content enhances the intragranular precipitation of MnS. It appears that an decrease in the onset temperature of overheating with the decrease in S content can be explained by the increase in Vs' due to coarsening austenite grain and the prevention of intragranular precipitation of MnS. The critical value of Vs' for preventing overheating was 5×10-5 mm3/mm2, which was obtained from the relationship between vEs and Vs'. Combination of Mn and S contents to get the Vs' of less than the critical value was determined.抄録全体を表示PDF形式でダウンロード (1030K) -
山田 人久, 桜井 隆, 竹之内 朋夫1990 年 76 巻 3 号 p. 438-445
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーIn solidification of low-alloy steels, micro-and macrosegregations are greatly affected by peritectic reaction which determines the redistribution of solute elements during solidification and effects the susceptibility of internal crackings in continuous slab casting. However, little is known about the effect of alloying elements on the peritectic temperature. In this study, therefore, the effect of alloying elements on the peritectic temperature in low-alloy steels was studied using a differential thermal analysis and a new method was developed to construct quasi-binary phase diagrams for multi-component systems. It was found that Mn and Ni increase the peritectic temperature and Si, P, S, Cr, Mo, and V decrease it. This tendency was well explained in terms of α/γ phase stability parameter. Moreover, the accuracy of estimating solidus temperature was improved by taking the change in peritectic temperature into account.抄録全体を表示PDF形式でダウンロード (1079K) -
大内 博史, 小林 順一1990 年 76 巻 3 号 p. 446-453
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーIn order to consider why and how the fatigue crack growth in steel is accelerated in seawater, effects of environmental variables on fatigue crack growth rates were investigated. In this study, intermediate (Region II) Fatigue Crack Growth Rates (FCGRs) in a 660 MPa tensile strength steel were measured under various environmental conditions at 25°C, using compact type specimens. Those experiments showed that decrease of corrosion rate by cathodic protection at-0.8 V vs. SCE or deoxygenation was not effective to lower the FCGR in synthetic seawater. Also anodic polarization at-0.6 V vs. SCE did not influence the FCGR. These results suggest that corrosion reactions do not influence the FCGR in seawater.
On the other hand, salts dissolved in seawater did not affect the FCGR and the increase of water contents in ethanol and glycerin accelerated the FCGR. Water must be the substance which accelerates the FCGR. In addition, FCGRs in some oils or other noncorrosive liquids, i.e. liquid paraffin, hydraulic oil, oleic acid and linoleic acid were greater than that in air, although the FCGR in 1, 1, 2-trichloro-1, 2, 2-trifluoroethane was almost equal to that in air. Therefore, it was concluded that hydrogen atoms dissociated from environment substances caused the fatigue crack growth acceleration.抄録全体を表示PDF形式でダウンロード (914K) -
小泉 裕, 冨塚 功, 原田 広史, 前田 達之, 中沢 静夫, 山崎 道夫1990 年 76 巻 3 号 p. 454-461
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーEffects of boron and carbon contents on tensile properties at 760°C were investigated for Ni-base PM-alloys with compositions fixed for main components (content of gamma prime phase : 65%). The obtained results were compared with those of cast alloys with the same composition of main component.
When specimens were prepared by powder-metallurgical procedures-HIP-consolidation of alloy powder, superplastic forging of it, or additional heat treatment on either of the former two-, Yield Strength (YS), Ultimate Tensile Strength (UTS) and Elongation to fracture (EL) were improved by addition of a small amount of boron (say 0.02%) except for the case of as-forged products. However, EL deteriorated by further increase in boron content, although UTS and YS remained almost unchanged. YS, UTS and elongation deteriorated, when carbon content increased from 0.02% to 0.20%. The properties of the HIPed or forged products were improved by an appropriate heat treatment.
When specimens were prepared by casting, trend seen for as-cast products was not much different from what was seen for as-HIPed ones. After the same heat treatment, however, the properties abruptly deteriorated. EL vanished and UTS decreased by more than 30%.抄録全体を表示PDF形式でダウンロード (7383K) -
品川 一成, 西川 裕之, 石川 孝司, 細井 祐三1990 年 76 巻 3 号 p. 462-468
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーTemperature dependence of deformation-induced martensitic transformation in type 304 stainless steel is investigated by homogeneous compressive test which is carried out over large strain in the temperature range from 20 to 100°C.The results obtained for the volume fraction of martensite vs.plastic strain relationship at each temperature are formularized as a simple expression in order to develop a numerical simulation of martensitic transformation progress during cold upsetting.Distribution of martensite in specimens upset on hydraulic press or mechanical press is investigated by a coupled usage of magnetic measurement and X-ray diffraction.While the distribution profile of martensite volume fraction is rather clear in the specimens upset on hydraulic press because of inhomogeneous deformation, that found in speci mens upset on mechanical press is somewhat vague due to temperature rise.Amount of deformationinduced martensitic transformation during cold upsetting is calculated by a simulation on the basis of strain and temperature distribution obtained by a coupled analysis of Finite Element Method(FEM)and Finite Difference Method(FDM).As for upsetting on hydraulic press the calculated result is smaller than the experimental result under the general complex deformation condition, however the distribution pattern looks common to both.抄録全体を表示PDF形式でダウンロード (953K) -
澤井 巌, 奥野 嘉雄, 泉 博之, 三沢 俊平1990 年 76 巻 3 号 p. 469-474
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーEffect of cure schedule and test temperature on tensile shear adhesion strength was investigated in a S55C high carbon steel/epoxy resin adhesive system, and was discussed the interrelations among shear, tensile and peel adhesion strengths. The results obtained are as follows :
(1) Probability distribution of adhesion shear strength was found to be followed by Weibull distribution.
(2) Shear strength obtained for various heating temperatures and its holding times, tested under 20°C, was divided into three stages in Larson-Miller parameter plot, that is, incomplete adhesion stage I of interface failure, suitable adhesion stage II of cohesive failure and deterioration adhesion stage III of cohesive-interface mixing failure mode.
(3) The test temperature dependence on shear strength having peaks was observed and the fracture mode was cohesive failure below 40°C corresponding to the temperature of a maximum strength, whereas shear strength decreased gradually with the appearance of an interface failure above 40°C.
(4) There lay a positive linear correlation between shear and tensile adhesion strengths, in addition to similar relationship between peel and tensile adhesion strengths.抄録全体を表示PDF形式でダウンロード (5875K) -
宋 小芳1990 年 76 巻 3 号 p. 475-477
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーPDF形式でダウンロード (428K) -
大中 逸雄1990 年 76 巻 3 号 p. 482
発行日: 1990/03/01
公開日: 2009/06/30
ジャーナル フリーPDF形式でダウンロード (319K)
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