巻号一覧
75 巻, 4 号
選択された号の論文の10件中1～10を表示しています
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論説
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堀尾 浩次, 豊田 和洋2004 年 75 巻 4 号 p. 231-236
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーThe influence of oxygen and calcium in the surface layer of titanium welding wire on arc stability and droplet transfer in pulsed metal inert gas (MIG) welding was investigated. Outbreak phenomenon of the arc was classified into two types, a concentrated arc and a sprayed arc. In both types, cathode spots were generated stable position on base metal by the effect of oxygen in welding wire surface. With regard to droplet transfer, droplets were formed and transferred into molten pool stably in case of the concentrated arc, whereas droplets were not formed often or their travel times into molten pool were enlarged in case of the sprayed arc. The results of the investigation are concluded that the calcium in the surface layer of welding wire makes the arc stable and the oxygen in it assists the droplet transfer.抄録全体を表示PDF形式でダウンロード (1771K) -
上仲 明郎, 乾 圭吾, 清水 哲也, 江幡 貴司, 滝口 常美2004 年 75 巻 4 号 p. 237-243
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーSoft-magnetic stainless steels have been used for high precision equipment. Their good machinability is rendered by Pb and/or MnS dispersed in them. From the viewpoint of health, Pb is an undesirable element. And MnS deteriorates the corrosion resistance and cold formability. A titanium carbosulfide, Ti4C2S2, is thermodynamically more stable than MnS and it is considered to replace MnS.
Effect of titanium carbosulfide on weldability of a soft-magnetic stainless steel has been investigated. Regarding a laser-welded joint of this steel plate and Type304 stainless steel plate, weld bead appearance and shape of penetration were equivalent to those of conventional stainless steel. There were no welding cracks in the weld bead, and there were few microporosities in the case of lower heat input than 0.225kJ/cm. Furthermore, welded joint was ruptured in base metal or HAZ of Type304 stainless steel plate in tensile test, so the mechanical property of welded joint was excellent.抄録全体を表示PDF形式でダウンロード (1041K) -
渡部 健司, 北村 陽一郎, 殷 福星2004 年 75 巻 4 号 p. 245-252
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーThe effects of alloy composition and heat treatment on the damping capacity and strength of MnCuNiFe damping alloys were investigated in this study. It is observed that:
When Mn composition is varied from 70.5 to 75.9 mass%, the fcc-fct phase transformation temperature increases with the increase of Mn composition at a rate of 3.2K/mass% Mn. This value is larger than the 1.9K/mass% Mn that is expected from the MnCu phase diagram. It is indicated that Mn enriched regions form in the alloys during the controlled slow-cooling process. Meanwhile, increased Ni content enhances not only the twin-boundary damping peak, but also the damping capacity above the transformation temperature of the alloy. The hardness, the strength and the transformation temperature of the alloy can be related to the degree of uneven distribution of Mn and Cu during the ageing process. The aged Ni added MnCuNiFe alloy is found to show the enhanced damping capacity in the temperature range above the transformation temperature because of the gradually continuous transformation.抄録全体を表示PDF形式でダウンロード (228K)
解説
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神谷 修2004 年 75 巻 4 号 p. 253-260
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーAustenitic stainless steel was welded by GTA and GMA methods in high pressure up to 6.1MPa nitrogen pressure. Welding condition, nitrogen absorption and microstructure of solidified metals have been investigated.
Nitrogen content (N) of GMA solidified metal increased from 0.2 to 0.65 mass% with increasing in pressure from 0.1 to 6.1 MPa. The fracture toughness of the weld metals was measured by means of the Charpy impact test at test temperature range from 77K to 290K. The Vickers's hardness number increased from 225HV to 350HV with N. The toughness increased with N up to 0.4%. However, N exceeded about 0.5% the intergranular fracture was easily caused by Cr2N and solidification micro cracks. Cr2N at the grain boundary can be absorbed in γ matrix and micro cracks were prevented by several % of Mn additions, then the fracture toughness at low temperature can be improved.抄録全体を表示PDF形式でダウンロード (634K) -
上山 智之2004 年 75 巻 4 号 p. 261-267
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーThe technology trend of gas shielded arc welding system is described on the view point of arc welding process. In the recent inverter controlled welding power sources, the reliability of welding quality and productivity are improved since various welding current wave form controls are realized by introducing digital control. The wire feeder with an encoder and servo feedback motors, achieves not only improving wire feeding accuracy but also spatter free ignition of arc.抄録全体を表示PDF形式でダウンロード (480K) -
杉山 憲一, 川村 聡, 長坂 浩志, 屋代 利明, 近藤 鉄也2004 年 75 巻 4 号 p. 269-276
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーFor fluid machinery used in seawater, the overlaying technique is an effective means for the resistance to corrosion, erosion and abrasive wear in terms of cost, performance and repair. Therefore, we had attempted to combine the manufacturing technique of anti-wear resistant Co based KV powder and Crevelloy alloy with excellent crevice corrosion resistance. As the results, the overlayer containing 15%massVC, 35%massCr, and 15%massMo shows high hardness and excellent anti-corrosion property. High hardness of overlayer is mainly caused by matrix phase with lamellar structure consisting Ni-Cr-Mo-Fe alloy phase and carbide phase. Corrosion property was evaluated by cyclic potentiodynamic anodic polarization curve measurement in 3.0%NaCl aq. at 25°C, pitting potential measurement in 3.5%NaCl aq. at 80°C and 6-months immersion test in seawater. Erosion property was evaluated by slurry jet test and vibratory cavitation erosion test. From the evaluation results, developed material VCRMO is recommended as overlaied alloy for seawater applications.抄録全体を表示PDF形式でダウンロード (559K) -
武田 裕正, 金子 浩幸, 小野寺 敏2004 年 75 巻 4 号 p. 277-281
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーThe glow discharge is risen between chamber and target in the mixed gas of hydrogen and ammonia. In this discharge the mixed gas changes to plasma, the reactive NH radical occurs and it leads to nitriding. Precise nitriding can be achieved on any materials according to purpose, because the reactive radical can be generated more efficiently than other nitriding technique.抄録全体を表示PDF形式でダウンロード (301K)
技術資料
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大矢 耕二, 前田 利秀2004 年 75 巻 4 号 p. 283-288
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーHeat resistant cast tubes have been used for ethylene cracking furnace. Creep strength, carburization resistance, and anti-coking characteristics are required for the tubes. We have developed a clad tube for ethylene cracking furnace, named PTT, which inner surface was claded with special metal by Plasma Powder Welding process. PTT have been introduced into the commercial furnaces and evaluated the performance. Results of the practical application trials were compared with conventional ethylene cracking furnace tubes and concluded as follows.
1) PTT in commercial furnaces showed longer run length by lower TMT (Tube Metal Temperature) tangent. Improvement of feed rate was also confirmed.
2) PTT's overlaid layer had Cr2O3 layer with no Fe. The oxide layer is considered to prevent catalytic coke formation.
3) Superior carburization resistance was confirmed by EPMA analysis. PTT's overlaid layer with high Cr content is considered to prevent carburization of the tube.
4) Superior carburization resistance and anti-coking characteristics of PTT are confirmed. Extensions of run-length and tube life are realized by PTT.抄録全体を表示PDF形式でダウンロード (498K) -
江幡 貴司, 滝口 常美2004 年 75 巻 4 号 p. 289-295
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーVoices of our customers in late 1990s requiring soft-magnetic steels with high hardness for high wear resistance and high durability drove us to launch research and development and we have succeeded in developing a new steel K-M57, Fe-15Cr based precipitation-hardened ferritic steel by modifying a base steel with high hardness above 400HV but not quite satisfactory concerning magnetic properties and manufacturability.
A simple relationship between concentrations of alloy elements and matrix phase has been found around the composition of base steel which gave us a confirmation about stability of ferritic matrix and helped us to design the new steel.
Newly developed K-M57 has both high hardness (>350HV) and high performance soft-magnetic properties (Hc<100A/m, μmax>2500μH/m, B2000>1.2Tesla) simultaneously, which satisfy the requirements of magnetic cores of various types of solenoid valves including fuel injectors of automobiles. It also has high corrosion resistance and high electric resistivity (ρ≅90μΩ-cm) suitable for highly responsive devices. K-M57 has also good manufacturability due to low hardness (<250HV) after solution treatment which enables cold-drawing. Machinability is not less than SUS304 containing 0.02mass%Sulfur.
It is expected that the demands for the new steel will further extend because of its potential for expanding freedom of solenoids' design and eliminating surface hardening treatment of parts as well as of eco-friendliness from them.抄録全体を表示PDF形式でダウンロード (1402K) -
山口 孝夫, 岩田 英敏2004 年 75 巻 4 号 p. 297-303
発行日: 2004/10/15
公開日: 2010/06/02
ジャーナル フリーIn recent years, SQUID (superconducting quantum interference device) technology has been developed for measuring the very low magnetic field generated from a human's physiology activity, and this technology is used for MEG (magnetencephalograph) and MCG (magnetcardiograph). In this way, the MEG and MCG have begun to be installed to the some hospitals as the medical devices. It is necessary to reduce the environmental magnetic field significantly, in order to measure the weak signals with high stability by using these devices.
We developed and manufactured the magnetic shielding room for this purpose. In this paper, shielding performance of the magnetic shielding room at the low intensity and low frequency magnetic field is introduced.抄録全体を表示PDF形式でダウンロード (411K)
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