MANUFACTURE OF CLAD WELDED STEEL PIPE

PURPOSE:To obtain a weld zone with satisfactory quality by removing unnecessary beads and then, performing cladding by welding with the same kind of metal as a clad part to prevent metal to constitute a non-clad part from penetrating into the cladding weld zone. CONSTITUTION:At the time of forming plate edges 3a and 3b of clad steel strips into a tubular shape, clad steels 1 to be the edges in opposition and the inside of the range including a part of non-clad steels 2 are subjected to edge preparation and formed into the tubular shape with the clad steels 1 as the inside diameter. The non-clad steels of the plate edges 3a and 3b are then joined by resistance welding and the unnecessary beads swollen on the pipe inner and outer surfaces of a joining part are removed by cutting tools 4, etc., and subsequently, cladding by welding 5 is performed on a groove part with the same kind of metal as the clad steels. By this method, the weld zone with the satisfactory quality can be obtained.