With the aim of reducing the consumption of chamotte brick and possible mechanization of lining operations, the Zaporozhe Industrial Institute, in collaboration with the ' Zaporozhstal'" Works, has made industrial tests on monolithic linings of steel-tapping runners made of chrome--magnesite compound.At present the steel-tapping runners at the Zaporozhstal' Works are laid with chamotte bricks, of which the specific consumption is about 1.4 kg/ton steel. To protect the masonry from the action of fused metal and slag, it is covered with a layer of chamotte--clay--coke compound. However, the high open porosity (39.~7o) and low compressive strength (2.5 MPa) of the coating do not satisfy the service conditions of the lining. During tapping the fused steel erodes the protective coating and the lining. Moreover, the metal and slag stick to the masonry.

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.