Tetsu-to-Hagane

Combustion Technology in Steel Industry

Tomio SUZUKI

1990 Volume 76 Issue 6 Pages 807-816
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_807

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Recent Advance in Fluidization Technology

Shigekatsu MORI

1990 Volume 76 Issue 6 Pages 817-824
Published: June 01, 1990
Released on J-STAGE: May 07, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_817

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Development of Heat-pattern Control System along the Width Direction of Sintering Bed

Ryuichi NAKAJIMA, Shinichi KUROSAWA, Hiroshi FUKUYO, Takashi WADA, Ryo ...

1990 Volume 76 Issue 6 Pages 825-831
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_825

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Sintering condition fluctuates considerably in sintering bed, particularly at large scale sintering machines. The fluctuation deteriorates the quality, yield and productivity of sinter. The fluctuation, therefore, must be controlled to improve both the quality and the sinter operation.
The heat-pattern control system along the width direction of sintering bed has been developed and applied to Ohgishima Sintering Plant at Keihin Works. This system unifies automatically the sintering speed along the width direction by measuring waste gas temperature under pallets at No. 18, 20 and 22 wind box to evaluate the fluctuation and by controlling the five charging gates divided along the width direction of sintering machine.
The coefficient of variation of the waste gas temperature at No. 20 wind box decreased to 0.06 from 0.19 by applying the control system. The sinter quality, the return fine amounts and the productivity of sinter were also improved by decreasing the fluctuation.

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Low Silicon Operation in Blast Furnace with Flux Injection through the Tuyeres

Ryuichi NAKAJIMA, Sumiyuki KISHIMOTO, Hirohisa HOTTA, Akio SIMOMURA, K ...

1990 Volume 76 Issue 6 Pages 832-839
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_832

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For the purpose of decreasing Si content in hot metal by means of flux (CaO, MgO) injection through the blast furnace tuyeres, fundamental experiments and operational tests at Keihin No. 2 blast furnace were carried out. Results obtained are as follows.
(1) The generation rate of SiO gas (K'_SiO) based on fundamental experiments were formularized as follows.
K'_SiO= 4.07 × 10⁷ × exp (-120 × 10³/RT) × α_SiO₂
(2) For decreasing Si content in hot metal, MgO flux injection from the tuyeres was proved to be more effective than CaO flux injection. As to the charging method of flux, tuyere injection is most effective followed by top charging with coke and top charging with ore.
(3) The decrease in Si content in hot metal by MgO injection was estimated to be mainly due to the decreased generation rate of SiO gas with decreased activity of SiO₂ in raceway slag, which is formed by the reaction of coke ash and injected MgO flux.
(4) According to magnesite injection of additional 10 kg/t from the tuyeres, Si decreases due to MgO increase in hearth slag and raceway slag were estimated to be 0.009% and 0.045% respectively.

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Bubble Characteristics in the Momentum Region of Air-Water Vertical Bubbling Jets

Manabu IGUCHI, Hirotoshi KAWABATA, Toshikatsu IWASAKI, Kentarou NOZAWA ...

1990 Volume 76 Issue 6 Pages 840-847
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_840

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The vertical bubbling jet region in a cylindrical vessel can be classified into four subregions. They are named the momentum, transition, buoyancy and surface regions from the nozzle exit toward the bath surface. However, the bubble characteristic in each region is not clear even in air-water bubbling jets. The present paper proposes empirical correlations for the bubble frequency and gas holdup in the momentum region in air-water bubbling jet. The momentum region is defined as the region where the gas holdup on the centerline decreases from 100 to 10%. These correlations are applicable to bubbling jets of the modified Froude number from about unity to 2 × 10⁵.

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Measurement of Heat Transfer Rate between Particle and Fluid in Counter-current Moving Beds

Tomohiro AKIYAMA, Reijiro TAKAHASHI, Jun-ichiro YAGI

1990 Volume 76 Issue 6 Pages 848-855
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_848

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For heat transfer between particles and fluid stream in industrial moving beds like as blast furnace and shaft furnace for direct reduction, the significant discrepancy has been reported between actual heat transfer rate and that estimated by empirical correlations.
Three modes of steady-state heat transfer experiments have been carried out between nitrogen stream and hematite pellets in a laboratory scale counter-current moving bed reactor. Longitudinal distribution of both pellet and gas temperatures were measured by sheathed thermocouples inserted at the center of the pellet and protruded from inner wall by 5 mm, respectively. In the measurements, thermal gradient was not found within the pellet because of Bi<0.15 where Bi is Biot number. Heat loss through the wall of the bed was also measured by a heat flow meter.
The observed results have been correlated in terms of Nusselt, Reynolds and Prandtl numbers to give :
Nu= 2.0 + 0.39 Pr^1/3Rep^1/2 (150<Rep<400)
The coefficient 0.39 obtained here is considerably small compared with those of reported correlations.

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Disintegration of Bubbles and Acceleration of Gas-Liquid Reaction with Ultrasonic Vibrating Nozzle in Water Model Experiment

Masahiro KAWAKAMI, Naoyuki TONO, Shouichi DOUWAKI, Koin ITO

1990 Volume 76 Issue 6 Pages 856-862
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_856

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The possibility to disintegrate bubbles and to accelerate gas-liquid reactions has been investigated by applying ultrasonic vibration to the injection nozzle in water model experiment. The formation of fine bubbles was examined by visual observation. The acceleration effect was examined in absorption of CO₂ to NaOH solution and distilled water, and desorption of CO₂ from the latter solution. The bubbles were disintegrated by the application of ultrasonic vibration. The effect was remarkable at low gas injection rate. At high gas injection rate, however, large bubbles were formed discontinuously along with the fine bubbles formation. The fine bubbles penetrated deeper into the solution due to the jet stream induced by the ultrasonic vibration. All of the above gas-liquid reactions were accelerated by the application of ultrasonic vibration. This was attributed both to the larger interfacial area caused by the disintegration of bubbles and to longer residence time of bubbles in the solution. The mechanism of the disintegration is considered as follows : in the negative pressure period of vibration, cavities are formed in the vicinity of nozzle tip, where some amount of gas penetrate into, then the gas is disintegrated into fine bubbles in high pressure period of vibration. There existed the optimum nozzle dimension to accelerate the reaction, which was determined by compromise between linear velocity of gas and amplification of vibration at nozzle tip.

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Controllability of Particle Size and Efficiency of Electromagnetic Energy on Electromagnetic Atomization Process of Molten Metal

Shingo NINAGAWA, Kensuke SASSA, Toshiyuki KOZUKA, Shigeo ASAI

1990 Volume 76 Issue 6 Pages 863-869
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_863

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The electromagnetic atomization process in which molten metal was atomized by imposing electric and magnetic fields was studied. In order to improve the controllability of this process, splashing phenomena of molten metal were visualized by use of a high speed camera and a VTR. The observed phenomena were carefully examined and main obstacles disturbing the continuous operation of the process and the sharp particle distribution were removed. A mathematical model was proposed for the better understanding of the process. On the basis of the visualization of splashing phenomena and the calculated results of the mathematical model, it was found that the particle size could be mainly controlled by the distance between a nozzle and an electrode, the delay time of electric current and the mass flow rate of molten metal. The impulse defined as the products of electromagnetic body force and the period of applying electric current, and the momentum of a splashed particle defined as the products of the mass and the velocity of a particle were calculated from the observed data. From the linear relation between the impulse and the momentum, the efficiency in which electromagnetic energy was transformed into the kinetic energy of a particle was evaluated.

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Stability Analysis of Free Surface of Liquid Metal Levitated by Electromagnetic Force

Shuji TAKEUCHI, Jacqueline ETAY, Marcel GARNIER

1990 Volume 76 Issue 6 Pages 870-877
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_870

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A theoretical analysis has been made to clarify the stability condition of Horizontal Electromagnetic Casting (HEMC) by means of the linear stability theory. The stabilities of thin plates and round rods of molten metal are analyzed when infinitesimal perturbation waves are added on the free surface of molten metal levitated by electromagnetic force.
The analysis reveals that influence of imposed magnetic field on the stabilization of perturbated surfaces is anisotropic and that the free surface of the metal is most stable when magnetic field is imposed parallel to the perturbation wave vector. The critical wave length which distinguishes stable condition from unstable one is 0.02 m for a molten steel plate with applied current density of 10⁶ A/m². This length practically limits the distance between a metal supply nozzle and solidified part of the metal.
The critical wave length for a round rod is almost the same as that for a plate if the diameter of the rod is the same as the thickness of the plate.

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Phosphorus Reaction between Molten Iron of High Carbon Concentration and Slag Containing FeO and Fe₂O₃

Pan WEI, Masamichi SANO, Masahiro HIRASAWA, Kazumi MORI

1990 Volume 76 Issue 6 Pages 878-885
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_878

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The phosphorus reaction between molten Fe-C-P alloy([% C] = 4.4) and Li₂O-CaO-SiO₂-Fe_tO slag has been investigated under the condition of mechanical stirring at 1300°C. The partial pressure of oxygen in the atmosphere and the initial concentration of Fe_tO in the slag were varied between 0 and 0.2 atm and between 3 and 15%, respectively. The initial concentration of P in the metal was below 0.1%. In the case of rephosphorization experiment the initial concentration of P in the slag was 1.1%.
The dephosphorization rate is much affected by the initial concentration of Fe_tO in the slag and the partial pressure of oxygen in the atmosphere, but not affected by the mechanical stirring. In the case of rephosphorization experiments the rate of rephosphorization of metal increases with increasing rotating speed of stirrer. It is found that the maximum ratio of phosphorus concentration in the slag to that in the metal ((% P)/[% P])_max largely increases with increasing Fe³⁺/(Fe²⁺+Fe³⁺) which is dependent on the partial pressure of oxygen in the atmosphere. The ratio of ((% P)/[% P])_max decreases with increasing rotating speed of stirrer larger than 50 rpm. A mathematical model is developed to explain the experimental results. It is shown that the present model can interpret the simultaneous reactions between molten iron of high carbon concentration and slag containing FeO and Fe₂O₃.

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Analysis on Buckling of Steel Plates in a Process of On-line Controlled Cooling

Naotake YOSHIHARA

1990 Volume 76 Issue 6 Pages 886-893
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_886

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During on-line controlled cooling of continuous motion type, steel plates are subjected to successive water cooling from the top to the bottom. Therefore thermal gradients in the longitudinal direction necessarily arise. Especially in the cooling which requires a large temperature drop like direct quenching, the plates will buckle by thermal stress generated from the longitudinal temperature gradient and shape problems will occur.
Those plates are flattened by hot leveler, but afterward the buckling may occur during air-cooling, if the temperature in the plates is not uniform just after the leveling.
We carried out the finite element method analysis on buckling caused by thermal stress which arose from the longitudinal temperature distribution during and after the controlled cooling.
The following terms were examined quantitatively.
(1) Effect of the zone length of controlled cooling, the plate thickness and the plate width on the buckling behavior during and after the controlled cooling.
( 2) Arrangement condition of pinch rolls for avoiding the buckling under the controlled cooling.
The knowledge obtained from the analysis contributed to the development of the controlled cooling equipment in the plate factory of NKK's Keihin Works. Now it is useful for the guide in the actual operation.

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Effects of Alloying Elements and Thermomechanical Treatment on Mechanical and Magnetic Properties of Cr-Ni Austenitic Steel

Toshihiko TAKEMOTO, Yasushi MURATA, Teruo TANAKA

1990 Volume 76 Issue 6 Pages 894-901
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_894

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Effects of alloying elements and thermomechanical treatment on mechanical and magnetic properties of Cr-Ni austenitic stainless steel have been investigated.
N and Si increase hardness after cold rolling as well as strain age hardening. Si decreases γ stability with respect to α' transformation, while other alloying elements increase it. Nonmagnetism can be maintained by controlling Ni_eq, an index of γ stability. High strength-nonmagnetic stainless steel can be obtained by utilizing strain age hardening and Ni_eq.
Si changes deformation mode from dislocation multiplications to formation of stacking faults. Si increases X-ray halfwidth at a given cold rolled condition, while decreasing it after aging treatment. It is considered that a large strain age hardening by Si is attributed to increase of internal strain and precipitation hardening. The decrease of γ stability by the addition of Si may be due to the accerelation of formation of α' phase by virtue of ε phase.

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Effects of Surface Texture on Cooling Curve during Quenching of Heated Metals in Subcooled Water

Michiharu NARAZAKI, Sadakatsu FUCHIZAWA, Masamitsu INABA

1990 Volume 76 Issue 6 Pages 902-909
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_902

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The effect of surface texture on the characteristic temperature during quenching of silver, nickel and SUS 304 stainless steel cylinders in still subcooled water has been investigated. The following results were obtained,
1)The surface texture of specimen does not affect the cooling characteristics at initial solid-liquid contact stage and next vapor blanket stage. But the characteristic temperature and its dependence on liquid subcooling are strongly affected by the surface texture.
2) The characteristic temperature becomes higher with increase of surface roughness and liquid subcooling. Even if the surface roughness are nearly equal, the characteristic temperature is affected by the surface geometry which varies with the methods of surface finish.
3) If the surface of specimen is sufficiently roughened, the characteristic temperature becomes higher with increase of liquid subcooling and its dependence on liquid subcooling shows a similar tendency to that of HENRY's equation. On the other hand, if the surface is sufficiently smooth, the characteristic temperature approaches to the values predicted by hydrodynamic model by BERENSON.

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Effects of Chemical Composition on the Heat-treatment Response of Ti-15V-3Cr-3Sn-3Al Based Beta Titanium Alloys

Naotake NIWA, Taizou DEMURA, Kunio ITO

1990 Volume 76 Issue 6 Pages 910-916
Published: June 01, 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_910

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On Ti-15-3 (a shortened designation for Ti-15V-3Cr-3Sn-3Al) and other two alloys which contain less V and Cr and more Al compared with Ti-15-3, the effects of alloy elements Al, V and Cr on beta transus temperature, aging behavior and mechanical properties were examined.
This variation in composition causes a little increase in beta transus temperature and nose temperature. At fully aged condition, it produces a little increase in hardness and great increase in alpha phase volume fraction. Among the effects, it is notable that it produces rapid aging to fully aged condition, however, it does not alter the strength-ductility relationship in fully aged condition.

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Saturation of Damage in Fretting Fatigue of High Strength Steels in Seawater

Kozo NAKAZAWA, Masae SUMITA, Norio MARUYAMA

1990 Volume 76 Issue 6 Pages 917-923
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_917

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The saturation behaviors of damage in fretting fatigue at frequencies of 1 and 20 Hz in seawater under freely corroding condition were studied using high strength steels having tensile strengths of 490, 690 and 880MPa. Fretting damage saturated beyond a certain number of fretting cycles, and this number varied drastically with the steel and the frequency. The saturation behaviors of damage could be divided into two groups, that is, the smallest numbers of fretting cycles to cause the saturation were less than 0.1% of the fretting fatigue life (group 1) and more than 40-60% (group 2). They had a strong relationship to crack initiation and growth behaviors. In group 1, cracks propagated normal to the alternating stress axis from the early stage of crack propagation. However, in group 2 the cracks propagated at angles less than 90° to the alternating stress axis, but changed direction to become normal as they propagated beyond a certain length. This relationship could be explained from the mechanism that the decrease in the fretting fatigue lives of group 1 resulted from the decrease in crack initiation life caused by the acceleration of corrosion pit formation, and that of group 2 from crack initiation and growth caused by fretting.

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Subsurface Crack Initiation in High Cycle Fatigue of Ti-6Al-4V Alloys at Cryogenic Temperatures

Osamu UMEZAWA, Kotobu NAGAI, Keisuke ISHIKAWA

1990 Volume 76 Issue 6 Pages 924-931
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_924

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In titanium alloys subsurface fatigue crack initiation occurs apparently without the existence of any defects such as inclusion or pore. We investigated subsurface crack initiation and sub-crack for Ti- 6Al-4V alloys at cryogenic temperatures, and discussed the growth mechanism of microcrack.
As the maximum stress was decreased, the morphology of subsurface crack initiation sites was changed from consisting of one facet to of more facets. The facet was identified as a cracked α phase by comparing their chemical composition and morphology. Sub-cracks were also produced in α phase. The subsurface crack initiation sites and the ub-cracks were not perpendicular to the applied stress. Hence it is concluded that a microcrack initiates in a α grain, grows into neighbor β plates and α grains, and finally forms an initiation site for a main fatigue crack. The lower the maximum stress, the greater the size of subsurface crack initiation sites. We adopted the size of the projection of subsurface crack initiation site on the main crack propagating plane, as a shape parameter of three-dimensional crack. Using this parameter, the dependence of initiation site size on the maximum stress range can be accounted for by an assumption that the microcrack growth is controlled by a threshold condition.

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Effect of Microstructure on Fracture Toughness of Ti-15V-3Cr-3Sn-3Al Alloy

Takao HORIYA, Hirowo G.SUZUKI, Teruo KISHI

1990 Volume 76 Issue 6 Pages 932-939
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_932

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Effect of microstructure on fracture toughness of β type Ti-15V-3Cr-3Sn-3Al alloy (Ti-15-3) was systematically examined.
At 0°C, fracture toughness (δ_c) is gradually decreased as strength (0.2%PS) increased. A linear relationship is obtained between fracture toughness and strength, regardless of microstructure: morphology of precipitated a phase or β grain size. Compared with (α + β) type Ti-6Al-4V alloy (Ti-6-4), Ti-15-3 has almost the same δ_c, in the strength range of 80 to 90 kgf/mm² and has a higher fracture toughness above the strength of 100 kgf/mm². The difference in fracture toughness between Ti-15-3 alloy and Ti-6-4 alloy is attributed to the difference in crack extension resistance of microcracks developed at the notch tip before unstable fracture.
At -196°C, fracture toughness is linearly decreased with increasing strength, independent of microstructure. However, the decrease in fracture toughness is rather small. Contrary to the case at 0°C, Ti-15-3 had a lower fracture toughness near the strength of 150 kgf/mm² than that of Ti-6-4. This is because Ti-15-3 had a lower crack initiation toughness (δ_i) than Ti-6-4 at -196°C.
It was found that crack initiation toughness (δ_i) of Ti-15-3 has a close relationship with reduction of area in the round bar tensile test. And crack resistance property was greatly influenced by both strength and the size of a phase precipitated during aging.

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Fabrication and High Temperature Properties of Single Crystal Component of Advanced Ni-base Superalloys

Yoshio OHTA, Yukiya G.NAKAGAWA, Shinichi OHAMA

1990 Volume 76 Issue 6 Pages 940-947
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_940

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A precision casting of high pressure turbine blades and vanes consisting entirely of an oriented single grain of nickel-based superalloys has been introduced in most advanced aircraft engines due to their superior high temperature strength. This paper presents a description of the casting process for single crystal components and the evaluation of high temperature properties for a newly developed alloy TMS26 in comparison with the existing alloys. Major outcomes are summarized as follows;
(1) Selecting the most adequate casting procedure and parameters, high quality single crystal blades in which their longitudinal orientation divergence from <100> was less than 10 degree were consistently procedured from TMS26 and CMSX-2 (an existing alloy) with a yield in excess of 90%.
(2)Mechanical properties (tensile, creep and low cycle fatigue strength) and several physical properties of TMS26 were found to be generally superior to those of existing commercial alloys.

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The Effect of P and Si Segregation to Grain Boundary on the Intergranular Corrosion of Type 304L Stainless Steel

Kishu HOSOI, Tsunenobu YOKOSUKA, Toshimi YOSHIDA, Isao MASAOKA, Yasuhi ...

1990 Volume 76 Issue 6 Pages 948-955
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_948

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The correlation between grain boundary segregation and intergranular corrosion in solution heat treated Type 304L stainless steel was examined. Grain boundary composition was analyzed with a high resolution analytical electron microscope (HRAEM). Intergranular corrosion susceptibility was tested in 9 kmol/m³ nitric acid solution containing 1 mol/m³ Ru at 373 K for 1.8 Ms. The followings are found: (1) The amount of phosphorus segregation to grain boundaries in solution heat treated stainless steels were successfully measured quantitatively with HRAEM. The amount of phosphorus segregation increases with higher phosphorus content, and the phosphorus concentration of grain boundary becomes about a hundred times of that of grain interior. (2) Phosphorus and silicon additions cause intergranular corrosion. The correlation between amount of phosphorus segregation and intergranular penetration depth is seen in low silicon content steels. But high silicon content steels show deep intergranular penetration depth, in spite of the small amount of phosphorus segregation. (3) Assuming MCLEAN'S model of equilibrium segregation, the segregation free energy of phosphorus at 1323 K is estimated as about 57 kJ/mol.

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Evaluation of Gas Turbine Materials for Low BTU Coal Gasification Generation

Toshiharu KOBAYASHI, Takashi ARAI, Takehiko ITAGAKI, Michio YAMAZAKI

1990 Volume 76 Issue 6 Pages 956-963
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_956

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The low BTU coal gasification-complex generation technique was the national project in Japan. In the project, selection of materials for the gas turbine was done. Coal gas which was supplied by gasifier of Coal Mining Research Centre was cleaned up, and then exposure of samples was done under combusting condition close to actual apparatus gas. Specimens of commercial superalloys which were diffusion-coated by aluminium or chromium were evaluated by appearance and by weight change after exposure. Maximum weight loss at 1 000 h was very small to be 11 mg /cm². But, under certain circumstances, weight loss of base alloys was considerably larger than coated samples. Therefore, the effectiveness of diffusion coating was recognized. The combution gas was found to be oxidative, because of formation of oxide scale. Sulfur was detected in a scale formed in both dry and wet cleaning methods of gas, and alkali metals were also detected in a scale formed in dry-cleaned gas. It was shown that there was influence of sulpheric corrosion on high temperature oxidation. If present samples are evaluated by estimating maximum scaling loss at 10000 h, there will be no problems from a view point of material deterioration.

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Microstructure and Mechanical Properties of an α-particle Irradiated Type 316 Stainless Steel

Kazuya MIYAHARA, Yasuhiro SAKAMOTO, Hideo KAYANO, Yuzo Hosoi

1990 Volume 76 Issue 6 Pages 964-966
Published: June 01, 1990
Released on J-STAGE: February 16, 2010

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_964

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[title in Japanese]

[in Japanese]

1990 Volume 76 Issue 6 Pages 977
Published: June 01, 1990
Released on J-STAGE: June 30, 2009

DOIhttps://doi.org/10.2355/tetsutohagane1955.76.6_977

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