Hitachi, Ltd.

Kouji Satou

Kenjiro Narita

Yukio Hirama

Kinya Aota

Hisanori Okamura

Kenichi Yasuda

Shinichi Kaga

Masahiko Sakamoto

Tadashi Nishino

Yasutsugu Yoshimura

Yoshio Takakura

Mitsuo Nihei

Ken-ichi Yasuda

Takehiko Saito

Yasutsuga Yoshimura

Ken-ichi Yoshimoto

Disclosed is a friction stir welding method for welding two members to be welded which differ in physical properties and/or mechanical properties by abutting the two members to each other, inserting a pin portion of a rotary tool having the pin portion and a shoulder portion to the abutment surfaces of the two members, and moving the rotary tool along the abutment surfaces. The pin portion is inserted to only one of the members, the pin portion is not inserted to the other of the members but only the shoulder portion is set in contact with the other of the members, and, while this condition is maintained, the rotary tool is moved. With this method, only the member on the side where the pin is inserted can be made to undergo plastic flow attendant on a friction stir action. The metal in plastic flow is pressed against the opposite member at an elevated temperature and high pressure, whereby diffusion of atoms is caused in the vicinity of the abutment surfaces, and the members are welded.

Friction stir welding method and component part welded by the method

A rolling mill is provided with a pair of work rolls 2, a pair of intermediate rolls 3 and a pair of backup rolls 4 in a mill stand 5, wherein the pair of backup rolls are arranged so that their axial lines cross perpendicularly a plate travelling direction and do not incline to the direction in a horizontal plane, the intermediate rolls and work rolls are arranged so that the axial lines of the intermediate rolls and the axial line of the work rolls incline to (cross) the axes of the backup rolls in a counter direction to each other in a horizontal plane, and a lubricant supplying apparatus 6 is provided for supplying a lubricant to the roll surfaces.

Rolling mill and rolling method

In a tandem mill system, at least one first type rolling mill is arranged in the upstream side and at least one second type rolling mill is arranged in the downstream side. The first type rolling mill is of the so-called work roll crossing mill in which a pair of work rolls are inclined with respect to a pair of back-up rolls supporting the work rolls and simultaneously crossed each other in a horizontal plane to control transverse thickness distribution of a strip. The second type rolling mill is of the so-called HC mill which controls the strip crown and shape by a combination of axial movement of intermediate rolls and work roll bending. Such an arrangement makes it possible to increase a capability of controlling the strip crown and shape, particularly, a capability of correcting the quarter buckle, and eliminate a fear of causing scratches on the strip and roll surfaces, with the result of improved production efficiency. Plural lines of lubricant supply device are also provided to stop supply of a lubricant immediately before biting of the strip into the work roll crossing mill and start the supply again after the biting. A system of lubricating the work roll crossing mill is thereby improved.

Tandem mill system and work roll crossing mill

In a system and method for manufacturing thin plate by hot-working, a splicing machine for continuously splicing the front edge of a following plate and the rear edge of a precedent plate is provided in the process precedent to a set of rolling mill stands having non-driven small diameter working rollers. By continuously splicing the plates, most portions of the rolled plates can be rolled under a steady state rolling condition, that is, an after-engaged rolling condition, and the thickness reducing amount of the plates in most portions of the rolled material is substantially increased, which substantially improves the rolling efficiency. Thereby, the diameter of the working rollers can be decreased smaller than the diameter of working roller used in a conventional rolling mill, rolling mill strands can be made small, and it can be realized to attain a small-scale system for manufacturing thin plate by hot working.

System and method for manufacturing thin plate by hot working

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Hitachi, Japan

Kouji Satou