Moscow Power Engineering Institute University (Moscow, Russia):

Merkulov D. V., Cand. Eng., Ass. Prof., the Chair “Technology of Metals”
Chepurin M. V., Cand. Eng., Ass. Prof., the Chair “Technology of Metals”, ChepurinMV@mpei.ru

Seversky Tube Works (Polevskoi, Russia):

Toporov V. A., Plant Manager

The paper is devoted to features of setting up the parameters of piercing mill at Seversky tube works. It is shown that the methods of setting up parameters of this mill can be different, depending on technological tasks. If we need to vary only reduction in front of the plug, with constant plug diameter, we can vary the distance between rolls. In the case we need to vary reduction simulaneously, it is necessary not only to vary the distance between rolls, but also to vary diameter and perhaps length of plug. Based on these principles, relative thin thickness of shells is analysed. It is displayed that practically the proposed adjusting methods can't be always realized, therefore plugs of one size are used for piercing of billets of several diameters and production of shells with different sizes. Dependence between requirements for setting of piercing mill and formulated technological tasks is displayed on the structural-logical scheme. Optimal piercing procedures have been developed based on the proposed technique and applying to the conditions of Seversky tube works. Parameters of final forming and mill setting for proposed procedures of piercing of continuously cast billets using plugs with corrected dimensions are presented. Parameters of cyclic forming along deformation area and accumulated shift deformation degree have been calculated using the mathematical model developed by the specialists of the Moscow Power Engineering Institute. Efficiency of the developed conditions and procedures has been confirmed by more intensive processing of cast structure and decrease of number of defects in obtained shells.

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