Tereschenko A. Development of calculating methods for the lowcyclic cold pilger rolling modes and straightening in the production of tubes with regulated quality indicators

The dissertation is devoted to developing methods for calculating lowcyclic modes, subject to certain laws governing the effect of the compression tube diameter to a depth of rolled-folds on the inner surface during rolling, and rational compression tube diameter, providing them with the hardening of the minimal editing. Methods for calibration of an instrument are to receive quality regulated tubes. Receive the development pattern of the influence of compression on the diameter of the tube blanks made of austenitic chrome-nickel and chrome-nickel-molybdenum steels in the appearance and depth of the rolled folds on the inner surface of the tubes in cold pilger rolling mills in the type of CPR. Accounting for patterns in the calculation of the geometry of the deforming tool allows you to minimize the amount of rolled-up wrinkles and improve the quality of tubes. The method for calculating the deformation modes with increased reductions of the diameter of tube billets was achieved. The dependence of yield stress and strength the deformation conditions of the metal tubes was found. Rational value of diameter reduction, depending on the area of cross section of a tube in the camp of longitudinal changes was found. A method for calibrating roller straightening machines, taking into account the rational compression values on the tube diameter was created. Experimental verification of the results obtained in production conditions showed improvement of quality ready-made tubes.