Improving the Deformation of Tube Billet in Continuous Roll Forming

A universal formula is proposed for calculating the optimal strip width and tube-billet perimeter at each stage of bending in the production of electrowelded low- and medium-diameter straight-seam tube and pipe of round and complex cross section. This formula determines the conditions of tube deformation in machines of different type and allows the increase in tube-billet perimeter in a group of stands with an open gauge profile to be taken into account for different forming behavior. For the tube and pipe range produced, the reduction at the tube-billet perimeter in a group of stands with a closed gauge profile should be no more than 0.6%. That decreases the steel consumption by decreasing the width of the initial billet, without loss of pipe quality, and increases the product yield by eliminating edge buckling in the course of forming.