FIELD: technological processes.
SUBSTANCE: invention relates to rolling of seamless pipes on mandrel in group of stands. Method involves rolling in group of stands for preliminary rolling and in group of subsequent rolling stands. Increased service life of used equipment by fact that it is determined whether preliminary stage stands are used in reduction of external diameter or in reduction of thickness of hollow tubular billet, and elongation of hollow tubular billet is made, to which rod of mandrel is inserted. During elongation and reduction of external diameter of hollow tubular billet in preliminary stage group of stands hollow tubular billet is rolled without contact of its inner surface with mandrel rod in preliminary stage stands and its inner surface in contact with rod of mandrel in stands of next stage, and during elongation and reduction of thickness of hollow tubular billet in preliminary stage stands hollow tubular billet is rolled in contact of its inner surface with mandrel rod in preliminary stage stands and stands of next stage.
EFFECT: device comprises appropriate equipment.
3 cl, 25 dwg
