Mathematical Model for Determining Depth of Deformation Penetration While Pipe Punching

This article speculates on the topic of inhomogeneity of crystal size in production of pipes with a diameter over 600 mm by means of punching and mechanical processing. It analyses literary data which allows to suggest that the reason for crystal inhomogeneity is inhomogeneity of deformation caused by voltage dissipation. There is a comparison of the punching process and mother pipe rolling on the stage of blooming where one can also observe voltage dissipation. It contains a conclusion stating similarity of these processes and suggests using the formula of Sun Rui Yu to evaluate the depth of deformation penetration on a piercing mill. There is an algorithm elaborated for usage of this formula requiring determination of a feed pitch. It should be noted that the given method suits only those mills where it is possible to ignore mother pipe twisting. The given method was used for calculating the depth of deformation penetration for one of the schedules. Possibilities and boundaries of method application are summarised.