Kabushiki Kaisha Toshiba

Toshiba Energy Systems & Solutions Corporation

Wataru Kono

Satoshi Okada

Masaki Yoda

Masataka Tamura

Hiromi Kato

Yoshinobu Makino

Masahiro Takeuchi

Daiki Tanaka

Tomoyuki Ito

Mitsuaki Shimamura

Katsuhiko Sato

Yoshio Hamamoto

Hiroyuki Miyasaka

Shigeki Maruyama

Yumiko Abe

Seiichiro Kimura

Koichi Soma

Yutaka Togasawa

Kenji Matsuzaki

Yoshinori Katayama

Minoru Obata

Hisashi Hozumi

Katsunori Shiihara

Yuuichi Motora

Yasuo Morishima

Hidenori Takahashi

Masakazu Abura

Taiji Kobayashi

Yoshimi Tanaka

Nobuichi Suezono

Takahiro Hayashi

Toru Sakamoto

Tomoharu Tanabe

A nickel-base alloy welding material according to an embodiment comprises: Cr (chromium) larger than 30.0% and less than or equal to 36.0% by mass; C (carbon) less than or equal to 0.050% by mass; Fe (iron) larger than or equal to 1.00% and less than or equal to 3.00% by mass; Si (silicon) less than or equal to 0.50% by mass; Nb (niobium)+Ta (tantalum) less than or equal to 3.00% by mass; Ti (titanium) less than or equal to 0.70% by mass; Mn (manganese) larger than or equal to 0.10% and less than or equal to 3.50% by mass; Cu (copper) less than or equal to 0.5% by mass, and a remainder is Ni and unavoidable impurities.

Nickel-base alloy welding material, welding material for nuclear reactor, nuclear power apparatus and nuclear power structure, and method of repairing nuclear power apparatus and nuclear power structure

A heating laser beam is emitted to a cracked portion to remove moisture from the cracked portion, and subsequently, a welding laser beam is emitted to the cracked portion to heat and melt the cracked portion. The heating laser beam and the welding laser beam are emitted to an entire surface of the cylindrical body inside the reactor such as a stub tube penetrating through and fixed to a reactor bottom portion and a crack of the welded portion between the cylindrical body and the reactor bottom portion to thereby prevent a new crack from occurring and reactor water from leaking.

Reactor bottom repairing method

According to one embodiment, a laser welding apparatus has a laser irradiation head that is arranged in an outer frame and is divided inside into a light source side and an irradiation side by a partitioning member. The apparatus also has a gas jet nozzle that is formed so as to irradiate a portion to be welded with the laser light and jet the inert gas to the portion to be welded; and a welding wire feed pipe that sequentially feeds a welding wire. The apparatus also has a welding wire contact mechanism that includes a measuring means for measuring a distance between the extremity of the irradiation side and the extremity of the welding wire, and is formed so that the extremity of the welding wire is brought into contact with and pressed against the portion to be welded by an elastic member.

Laser welding apparatus

A method of sealing a surface crack in a member is provided includes steps of irradiating a region of the member at which the crack is produced with a heating laser beam so as to heat the region to a temperature lower than a melting point of the member, and then irradiating a region of the member at which the crack is produced with a welding laser beam subsequent to irradiation of the heating laser beam so as to heat the region to a temperature higher than or equal to the melting point of the member, thereby sealing an opening of the surface crack of the member.

Surface crack sealing method

A repair method for a structure having an open flaw in a welding heat affected portion, including, removing at least a part of the open flaw and thereby forming a concave portion in the welding heat affected portion, forming build-up weld layers so as to fill the concave portion, treating a surface of the build-up layers to reduce tensile residual stress by means of at least one of laser peening, shot blasting and water jet machining. Also disclosed is an apparatus suitable for carrying out the repair method.

Repair method for structure and repair welding apparatus

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Yokohama, Japan

Wataru Kono