FRICTION STIR WELDING METHOD FOR STRUCTURAL STEEL AND METHOD OF MANUFACTURING JOINT FOR STRUCTURAL STEEL

摘要

The disclosure is intended to advantageously resolve plastic flow failure caused by insufficient heating of working materials to obtain a sufficient strength and improve welding workability when performing friction stir welding on structural steel. A process of pre-heating treatment is performed such that steel sheets or plates (3) as working materials are heated by a heating unit (5) provided ahead of a rotational tool (1) moving in a welding direction to precisely control the surface temperature, area, position and the like of a heating region in the process of pre-heating treatment when performing friction stir welding on structural steel.