WELD PART DETERMINATION METHOD AND WELD MATERIAL MANUFACTURING METHOD

摘要

In the present invention, a weld part determination method includes the following: an incidence step (S2) in which ultrasonic waves (US) from an insertion side and the side opposite thereto of a tool (1) are caused to be incident on a weld part (J) when a workpiece (W) formed by stacking plate members (Wa) is welded by the tool (1) that has a probe (2) and a shoulder (3) which supports the probe (2) and that is for friction stir welding; an image acquisition step (S3) for obtaining an ultrasonic wave transmission image of the weld part (J) using the ultrasonic waves (US); and a determination step (S4) for determining that the weld part (J) has been welded if the weld part (J) width-dimensions obtained from the ultrasonic wave transmission image are equivalent to at least the outer diameter d of the probe (2) and if no defect (JD) of a prescribed size or greater is found in a range equivalent to the outer diameter D of the shoulder (3) or less in the ultrasonic wave transmission image.