Jfe Steel Corporation

Shohei Iwata

Muneo Matsushita

Yasushi Kitani

Kai Tomita

Provided is an electrical steel strip friction stir welding method that is able to inhibit the occurrence of coil joint fractures on a production line caused by deterioration of mechanical properties and shape of the coil joint while maintaining high work efficiency and that is also advantageous in terms of rotating tool durability. In the method, preheated double-sided friction stir welding is performed, diameter D (mm) of shoulders of rotating tools satisfies the relationship of the following Expression (7), and rotation speed RS (r/min) of the rotating tools, the diameter D (mm) of shoulders of the rotating tools, and joining speed JS (mm/min), expressed as RS×D/JS, satisfy the relationship of the following Expression (8), 4×TJ≤D≤10×TJ . . . (7), and 180×TJ≤RS×D/JS≤1500×TJ . . . (8).

Electrical steel strip friction stir welding method and method of producing electrical steel strip

A double-sided friction stir welding method, methods for producing a cold-rolled steel strip and a coated steel strip, a double-sided friction stir welding apparatus, and facilities for producing a cold-rolled steel strip and a coated steel strip. The double-sided friction stir welding method includes pressing two rotating tools, which are disposed on a first surface and a second surface of a butt portion or overlap portion of the steel strips, against the butt portion or overlap portion of steel strips and moving the rotating tools in the welding direction while rotating the rotating tools in opposite directions to each other, so that an unwelded portion of the steel strips is softened by frictional heat generated between the rotating tools and the unwelded portion of the steel strips, and the softened portion is stirred with the rotating tools to generate plastic flow so as to weld the steel strips together.

Double-sided friction stir welding method, methods for producing cold-rolled steel strip and coated steel strip, double-sided friction stir welding apparatus, and facilities for producing cold-rolled steel strip and coated steel strip

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Tokyo, Japan

Shohei Iwata