LASER WELDING OF LARGE-DIAMETER TUBES Russian patent published in 2015 - IPC B23K26/262 B23K26/70 

FIELD: metallurgy.

SUBSTANCE: prior to welding of lengthwise weld, tack weld is made. Laser pickup arranged ahead of welding zone is used to register during making of said tack weld the three points over to tube entire length located on virtual crosswise plane of dressing: the points of butt of edges and two points of their ends located on tangent to tube crosswise plane. Data base on spacings between said points over the tube length is created. During the next root weld laser welding step used is the created data base for determination of edges ends with the help of scanning laser pickup. The latter is located at every time moment at preset position over the tube length. Now, position of third point is defined, that is, the point of butt of edges and laser beam is directed thereto by displacement of welding head.

EFFECT: higher quality of laser welding of tubes.

1 dwg