Studying the Wear Resistance of the Mandrels of a Two-High Screw Rolling Mill

The surface wear of a cylindrical mandrel during elongation rolling of 20Kh13 steel pipe in a MISiS-130D screw-rolling mill is studied. The dimensions of the mandrel were determined before and after the rolling. It is shown that after rolling five 72 × 9 mm hollow shells of 700 mm length, the diameter of the mandrel in the deformation zone decreased by 0.04 mm maximum. The material durability of the mandrel used was 28.5 ton/kg. The finite-element method was used to simulate the elongation rolling of shells into tubes on a short cylindrical mandrel. It was found out that the maximum wear is in the gorge zone, where the diameter dimensions of the mandrel decreased by 0.01 mm after each pass. The material durability of the mandrel decreased by 78.9% after five passes.