巻号一覧
72 巻, 3 号
Welding
選択された号の論文の7件中1～7を表示しています
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論説
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林 千歳, 篠田 剛, 加藤 喜久原稿種別: 総説
専門分野: 金属加工
2001 年 72 巻 3 号 p. 147-153
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーDirected Plasma Fabrication (DPF) is a rapid tooling process that is based on the controlled deposition of molten metal particles according to computer-controlled patterns. It makes fully dense, near net shape metallic components without casting, pressing or forging processes in molds or dies. Experimental works were carried out using a conventional low current Plasma Transferred Arc welding system, and the atomized Stellite #21 powder. Cylindrical shapes are successfully deposited into the wall 2.5-4.2 mm thick. The key factor is the non-dimensional "operating parameter n" which was proposed by Christensen. The better deposition efficiency is obtained with the shorter arc length and the slower traveling speed under the same plasma current.抄録全体を表示PDF形式でダウンロード (412K) -
乾 圭吾原稿種別: 総説
専門分野: 金属加工
2001 年 72 巻 3 号 p. 155-162
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーThe 19%Cr ferritic stainless steel wire has been applied to MIG and MAG welding for the automotive exhaust systems in 14%Cr steel sheet. Authors investigated the effect of minor alloying elements on the grain size of the weld metal and ascertained that the combination of 0.08%Ti, 0.04%Al and 0.1%N is optimal to refine grains through inducing in the weld the numerous rectangular titanium and aluminun nitrides fine 0.3-0.7Ém2 in section. The developed wire bearing the above elements is coated with Cu to secure the feedability and then to lessen spatters. The bead from it is flatter in shape and more resistant to hot tear than conventional beads. The finer grained weld possesses the high temperature strength and the corrosion resistance superior to the conventional welds and the oxidation resistance equivalent to the conventional ones.抄録全体を表示PDF形式でダウンロード (406K) -
堀尾 浩次原稿種別: 総説
専門分野: 金属加工
2001 年 72 巻 3 号 p. 163-170
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーThe transition liquid-phase (TLP) diffusion bonding process was recently tailored to join the tubes of duplex stainless steel, Fe-25Cr-6.5Ni-3Mo-2W-0.5Cu-0.3N, with a Ni brazing filler, Ni-7Cr-3Fe-4.5Si-3B. The butts cramped by a hydraulic system are heated up locally with an induction coil in Ar shield gas. While the bonding at the holding temperatures lower than 1250°C introduces a large amount of boron nitrides at the interface which degrade extremely the tensile strength of the joint, the higher temperature bonding eliminates them from the joint, whose strength is about 850MPa close to 1000MPa for the base metal. The coarser recrystalized grains in the stronger joint scatter the ultrasonic wave so significantly that the joint efficiency is judged non-destructively with the ultrasonic transmission test. The precipitates Fe-Cr-Mo in HAZ reduce substantially the impact value of the joint, which recovers to the original level after the post-heat treatment at 1100°C to dissolve them. Another precipitates Cr7C3 in HAZ don't impair the localized corrosion and the stress corrosion cracking resistance. The developed TLP process is a promising technology for joining the duplex stainless steel tubes at the site of oil fields.抄録全体を表示PDF形式でダウンロード (347K)
解説
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松井 仁志原稿種別: 技術報告
専門分野: 金属加工
2001 年 72 巻 3 号 p. 171-178
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーIn high quality arc welding of chasis parts, the pulsed MAG welding method is an essential technology. So it has been improved extensively for robotised welding. Through a combination of a pulsed current waveform and improved wire properties, the droplet volume can be reduced to around half of conventional one. As a result the critical speed to spatter- and defect-free welding is increased. On the other hand by using a wire reforming type torch, the deflection of the wire tip can extensively be restricted and controlled to aim at the target position in joints. As to welding galvanised steel, the vibration of the molten metal pool controlled by the arc force is effective for removal of porosities.抄録全体を表示PDF形式でダウンロード (321K) -
喜田 裕原稿種別: 技術報告
専門分野: 金属加工
2001 年 72 巻 3 号 p. 179-186
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーMost of the refining and petrochemical equipment are fabricated by welding. In addition to the construction of new equipment, the welding is extensively used to repair and modify existing ones. However, it is generally recognized that the weld is more susceptible than the base metal to degradation or damage such as mechanical failure and corrosion, and a lot of failure modes associated with the weld are observed in process plants. Accordingly, the proper welding design and fabrication considering the service conditions are vitally important in the engineering. On the other hand, the plant owners are seeking the way to operate and maintain their equipment in a more safe, reliable and cost-effective manner due to the increased global competition. This paper deals with the welding engineering to ensure the integrity and the reliability of equipment throughout the life cycle of refining and petrochemical plants.抄録全体を表示PDF形式でダウンロード (298K)
技術資料
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高木 柳平, 上仲 明郎原稿種別: 研究論文
専門分野: 金属加工
2001 年 72 巻 3 号 p. 187-193
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーAn arc welding termed "I2R process" is an attractive one to preheat the electrode wire and then to raise the deposition rate, but it has never been applied to the thin wire around 1.2mm in diameter. Authors recently succeeded in applying this process to the thin wire through the following devices and technologies. The special contact tip was newly designed to keep the contact pressure optimal for an enough period in welding. The proper insulator was employed to secure the heat shock resistance and the thermal conductivity of the tip. And the welding torch was stabilized to minimize spatters under the higher welding speed. The developed process was designated "HOT MAG" for its sufficient preheating. Some applications introduced in this paper prove that it is a promising process to weld thin steel plate for various automobile and earthmover components.抄録全体を表示PDF形式でダウンロード (321K) -
加藤 喜久, 屋代 利明原稿種別: 研究論文
専門分野: 金属加工
2001 年 72 巻 3 号 p. 195-200
発行日: 2001年
公開日: 2001/08/15
ジャーナル フリーThe recent deregulation allows the operators to extend the shutdown maintenance interval from the conventional one year to the maximal 4 years at their petrochemical plants, where the components should withstand the hostile service conditions, high temperature and pressure, and severe erosion and corrosion, more than before. Consequently it gets a crucial technical challenge to achieve greater durability of the components. Plasma Powder Welding (PPW) is an established overlaying process to yield the unrivaled erosion-corrosion resistance. As filler alloy powders for PPW, authors designed Co-Cr-Mo-V system DAPKV series bearing 1 to 4%C and 5 to 17%V, which disperse fine spherical VC carbides in the overlay. Even with higher C contents, they are ready to weld into the multi-layered beads up to 18mm in height, free from cracking without pre-heating. They develop the neat overlays with the RT-800°C hardness and the abrasion and wear resistance both higher than the conventional Co-Cr-W system Stellite series. Most of their mechanical properties are superior to Stellites'. Some components overlaid with KV10, 2%C and 9%V, proves their multiplied service lives at refineries and plastic injection shops.抄録全体を表示PDF形式でダウンロード (222K)
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