Hitachi, Ltd.

Kouichi Matsumoto

Toshiyuki Kajiwara

Masahisa Inagaki

Masahiro Hayashi

Junjiro Nakajima

Hideo Maki

Hiromasa Hirakawa

Iwao Takase

Hideaki Ishizaki

Toraki Sakuma

Nobukazu Yamamoto

Nobuhiro Okazaki

In a method of fabricating a channel box for use in a nuclear reactor, Zr-alloy sheet material is formed into a tubular channel box. The method includes solution heat treatment of the Zr-alloy sheet material including quenching from a temperature at which .beta.-phase is present. After the solution heat treatment, portions of the Zr-alloy sheet are thinned relative to other portions by a non-stressing thinning process, such as chemical etching in a bath. The corrosion resistance imparted by heat treatment is retained, and the heat treatment itself is easily performed on material of uniform thickness.

Method of fabricating a channel box or other part for a nuclear reactor

A roll bending apparatus for use in a multi-stage rolling mill adapted for rolling a hard material or a thin sheet material with a high uniformity of thickness along the breadth, with a high degree of accuracy and low energy. The rolling mill has work rolls of a comparatively small diameter. The amount of bend of the small-diameter work roll is controlled by the roll bending apparatus for attaining the high degree of uniformity of thickness along the breadth of the rolled material. The roll bending apparatus has, for each of said work rolls, a supporting member having a work roll supporting portion for rotatably supporting the work roll and rockable vertically about a fulcrum, and a bending force generating means adapted for engaging the supporting member so as to cause a rocking motion of the supporting member thereby applying a substantially vertical roll bending force to the work roll through the supporting member.

Roll bending apparatus for rolling mill

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Hitachi, Japan

Kouichi Matsumoto