IMPROVEMENTS IN WELDING HOLLOW FLANGE MEMBERS

摘要

An apparatus for in-line ERW welding of hollow flange steel members in a cold forming mill comprises a seem roll stand (60) rotatably supporting at least one seam roll (68) adapted in use to guide a free edge (34a,34b) of a contoured metal strip (30) into linear alignment with a predetermined weld axis spaced from said free edge on a surface of the metal strip. The apparatus also includes a weld box stand (61) supporting at least one pair of squeeze rolls (84a,84b), in use, adapted to urge the free edge (34a,34b) when heated to a predetermined temperature into fused engagement with a correspondingly heated weld axis on the surface of the strip (30). The squeeze rolls (84a,84b) co-operate to guide the free edge through a predetermined linear trajectory substantially along an incidence axis of a subsequent weld junction between the free edge (34a,34b) and the surface of the metal strip (30) whereby energy imparted to the cold formed member is focussed by a proximity effect along the predetermined weld axis.