Continuous profiling of welded pipe in an automatic line

Abstract

9 In the theory of weldedpipe production in auto� mated lines, calculation of the energy parameters is of great importance. The tractional and vertical forces within the con� tinuous rolling mill are fundamental to the design of the working tool, to selection of the mill configura� tion, to determination of the possibility of manufac� turing the required pipe range using specific equip� ment, and to the development of technological pro� cesses. The stability of the process is ensured by the specified distribution of forces, which, in turn, affects the formation of satisfactory welded profile in the mill. Various methods exist for determining the energy parameters of the equipment in formulating the geo� metric dimensions of the initial blank. These methods have particular advantages and disadvantages. For example, a method for calculating the param� eters of the roller strand, the forces, and the deforma� tion of the blank was proposed in (1). However, this method ignores the contact area of the tool and the blank and hence cannot determine the relation between the energy parameters of the process and the tool dimensions (the roller diameters at the bottom and at the flange). The total tractional forces required to move the blank, the length of the shaping segment, and the groove width may be calculated by the method in (2). However, the contact areas are again ignored. The cal� culated shaping forces are unrelated to the deformed state of the blank in the mill. A procedure for determining the energy parameters in strip shaping was outlined in (3). However, the deformation arising in profiling at the junction of the sides in the blank was ignored. The retarding axial force in the creep zone was also disregarded. In the present work, we propose a method for cal� culating the energy parameters in profiling round welded blank in fourroller grooves of a pipe mill, with uniform decrease in curvature of the sides over the external surface and decrease in the reduction over the cells (4).