Method and tool for friction stir welding

摘要

The tool for friction stir welding is a tool adapted to operatively engage a tube and a tubesheet to form a sealed joint. The tool has two components. The first component is a shoulder having orthogonal faces for simultaneously engaging the sheet and the tube, the shoulder defining a bore terminating in an aperture at the junction of the faces. The second component is a stir welding probe that is insertable into the bore and has an end exiting the aperture at the end of the bore. A forging pressure urges the shoulder against the junction of the tube and tubesheet. The probe is rotated about its axis, penetrating the tube and tubesheet and generating heat through friction to weld the tube to the tubesheet, while the shoulder is rotated about the tube so that the weld forms a seal about the circumference of the tube.

主权项

1. A tool for friction stir welding, comprising:
a shoulder having a planar bottom face and an arcuate inner face extending substantially orthogonal to the bottom face, the shoulder having a bore defined therein extending obliquely through the shoulder and terminating in an aperture defined proximate the junction of the bottom face and the inner face, the bottom face being adapted to apply a forging load against a tubesheet and the inner face being dimensioned and configured for rotation about a tube extending through an aperture in the tubesheet; and a stir welding probe insertable into the bore in the shoulder, the probe having a pin extendable through the aperture proximate the inner face and the bottom face of the shoulder, the probe being adapted for rotation by a motorized friction stir welding apparatus, whereby rotation of the probe forms a friction weld between the tube and the tubesheet and rotation of the shoulder about the tube during welding forms a weld joint seal around the tube.