Mitsubishi Heavy Industries Limited

The Kansai Electric Power Co., Inc.

The Tokyo Electric Power Company, Incorporated

Chubu Electric Power Company, Inc.

The Chugoku Electric Power Co., Inc.

Tohoku Electric Power Company, Inc.

Electric Power Development Co., Ltd.

Kyushu Electric Power Co., Inc.

Hokkaido Electric Power Company, Inc.

Shikoku Electric Power Co., Inc.

Hokuriku Electric Power Company

The Japan Atomic Power Company

Hironori Onitsuka

Takashi Ishide

Shuho Tsubota

Takashi Akaba

Takahiro Ota

Kazuhiko Kamo

Jun Fujita

Koji Okimura

Takahiro Ohta

Yasumi Nagura

Kenichi Kawanishi

Noriaki Sugimoto

Seiji Asada

Itaru Muroya

Norimasa Mori

Osafumi Nakajima

Yoshimasa Tukamoto

Kazuhiro Wakabayashi

Yoshiyuki Hemmi

An object is to provide a method and an apparatus for improving a residual stress in a tubular body, which are enabled to improve the residual stress reliably by clearly defining controlling rage for treatment conditions without depending on an installation state and configuration of the tubular body. When a cylindrical tubular body () is improved in its residual stress by locally irradiating an outer-circumferential surface of a welded portion (C) of the tubular body () with laser beams () and by moving an irradiation area (s) in an circumferential direction, a plurality thermocouples () are installed on the tubular body () to be improved, a temperature history of the outer surface of the tubular body () by the irradiation of the laser beam () is managed by measuring the temperature history itself.

Method for improving residual stress in tubular body

Aims are to provide a tubular-body residual-stress improving apparatus and an adjustment method thereof capable of adjusting irradiation position with favorable reproducibility, even when an optical fiber is eccentric. In the tubular-body residual-stress improving apparatus, an optical control unit () includes a rotational hold mechanism () for holding an optical fiber () in a manner that the optical fiber () is rotatable in a circumferential direction of the optical fiber (), and, if a position of an intensity peak of the laser beam from the optical fiber () in an axial direction of the tubular body () is offset from the center of an irradiation profile, a position at which the optical fiber () is held in the circumferential direction is adjusted by the rotational hold mechanism () so as to eliminate the offset or to minimize an influence of the offset.

Apparatus for improving residual stress in tubular body and adjustment method of the same

An object is to provide a method and an apparatus for improving a residual stress in a tubular body, which are enabled to improve the residual stress reliably by clearly defining controlling rage for treatment conditions without depending on an installation state and configuration of the tubular body. When an outer-circumferential surface of a welded portion of a cylindrical tubular body () is irradiated with a laser beam that circles around an outer circumference of the tubular body (), a heating width W in a circumferential direction heated by the laser-beam irradiation and a laser-beam moving speed V in the circumferential direction are set so that a stress in the circumferential direction in an inner surface of the tubular body () produced by the heating with the laser beam is at least larger than a yielding stress of a material that the tubular body () is made of.

Method for improving residual stress in tubular body and apparatus for improving residual stress in tubular body

A tip tool guide apparatus is brought into a water chamber of a steam generator of nuclear power equipment, and guides a tip tool, such as a shot peening head, along a necessary region. For this purpose, a tip tool guide apparatusis composed of a swivel support portion, a slide table, and a manipulator. The swivel support portionis self-supported and fixed within the water chamber, and turns the slide tableconnected thereto. The slide tableconnects the manipulator, and moves the manipulatorslidingly in a fore-and-aft direction. The manipulatorgrasps the tip tool at its leading end. For bringing into the water chamber, the swivel support portion, the slide table, and the manipulatorare separated from each other, brought in individually, and assembled within the water chamber to constitute the tip tool guide apparatus

Tip tool guide apparatus and method for bringing in tip tool guide apparatus

Growing community of inventors

Kobe, Japan

Hironori Onitsuka