Advanced technology of heat-exchange pipe roller rolling

Abstract

In this paper on the basis of experimental numerical investigations carried out and factory experience it is shown that the process of heat-exchange pipe roller rolling differs from a widely used idea that in the course of rolling a pipe approaches uniformly to a cylindrical surface of an opening in a pipe plate and then presses itself causing at that elasto-plastic deformations in a pipe plate. In fact, at rolling a pipe deformation occurs in the form of a rotating triangle (for three-roller rolling) with increasing sides. Pipe pressing to an opening side is carried out in some points the number of which grows with the increase of a rotational moment. At that, only an elastic deformation of bridges in a pipe plate takes place. The final contact stress in a coupling is caused by the interaction of different metal layers, a part of which is stretched, and another part is compressed.