Hitachi, Ltd.

Nissan Motor Company Limited

Takamitsu Nakazaki

Hisanao Kita

Yoji Akutsu

Yoshinori Karatsu

Norio Yokoba

Shinji Tanaka

Hiroshi Satoh

Hisanori Okamura

Nobuyuki Iizuka

Yuji Yoshitomi

Takeshi Araya

Takao Funamoto

Kazuhiko Kumata

Megumi Nakanose

Kei Kobayashi

Tatsuo Yonezawa

Masami Yada

Shota Iwakura

Tsuneo Kakimi

Toshimi Sato

Yasuzi Kawada

Takaharu Konishi

A Co-base alloy including, by weight, 0.03-0.10% C, not more than 1.0% Si, not more than 1.0% Mn, 20-30% Cr, 15-23% Ni, 3-10% W, 5-10% Ta and 0.05-0.7% Zr, is used as a welding material. A gas turbine nozzle has a crack repaired with a multi-layer weld using the Co-base alloy and a gas turbine for power generation employs the nozzle.

Gas turbine nozzle, power generation gas turbine, co-base alloy and

A method of forming a non-circular pipe having a different sectional shape in the longitudinal direction thereof by bending a raw pipe while applying pressure to the inside of the raw pipe, wherein the circumference of a section of the raw pipe is substantially equalized to the circumference of a section, corresponding to the section of the raw pipe, of the non-circular pipe after formed.

Method and apparatus for forming a non-circular pipe

A method of welding opposite end surfaces of two titanium alloy parts kept in alignment by a high energy-density welding process such as electron beam welding, laser beam welding or TIG arc welding, characterized by closely interposing an insert member of either practically pure titanium or Ti-Al binary alloy containing up to 3 Wt % of Al. Owing to thorough alloying of the inserted titanium with the constituents of the fused base metal, the weld metal in a weld joint obtained by this method is sufficiently high in both strength and toughness. By an optional postwelding heat treatment, the strength of the weld metal can further be enhanced.

Method of welding titanium alloy parts with titanium insert

A vacuum chamber for welding in which to place a workpiece is hermetically connected to a vacuum chamber for an electron beam gun in which to place an electron beam gun, and the former is kept at a vacuum of 1.times.10.sup.-4 Torr while the latter, at a vacuum of 1.times.10.sup.-6 Torr. The distance between the electron beam gun and the surface of the workpiece is made greater than the mean free path of gas molecules and metal vapor molecules generated in treating, e.g., 1.85 m. Two focusing coils are arranged to prevent the expansion of the electron beams.

Method of treating a workpiece with electron beams and apparatus therefor

An electron beam welding machine comprises an electron gun including a first beam adjusting means, a second beam adjusting means disposed spaced from the first beam adjusting means so as to be movable in the direction of an electron beam path, and position adjusting means for adjusting the position of the second beam adjusting means through rotary movement about an axis perpendicularly crossing the electron beam path and linear movements on a plane perpendicular to the electron beam path. The machine further includes a mirror and light source mounted on the electron gun to emit light on the electron beam path, and photodetectors mounted on the opposite sides of the second beam adjusting means so as to face the electron gun and a workpiece, whereby the correct position of the second beam adjusting means is detected.

Electron beam welding machine

An electron beam welding apparatus is provided with a magnetic shielding pipe for preventing electron beams emitted from being deflected by stray magnetic fields, and a removing device for removing metal deposit accumulated on a tip portion of the magnetic shielding pipe, which tip portion faces to a weld formed by welding of materials to be welded. The removing device is provided with at least a pair of shutters which move along a tip face of the tip portion to prevent the metal deposit from accumulating on the tip portion. The pair of shutters provides in their central portion a hole for passing electron beams therethrough when they are closed so that welding can continue irrespectively of the movement of the shutters.

Electron beam welding method and apparatus therefor

A method for welding dissimilar metals, wherein a filler metal is deposited on one end of the aforesaid dissimilar metals to be jointed, said filler metal being of the same material as that of another of said dissimilar metals; the outer surface of the weld metal thus deposited is machined to provide a joint surface adapted for welding; and an electron beam welding is applied along the interface formed between said joint surface of said weld metal thus deposited and the joint surface of another of said dissimilar metals.

Welding method for dissimilar metals

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Takahagi, Japan

Takamitsu Nakazaki