METHOD OF HELICAL PIERCING AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC B21B19/04 

FIELD: metallurgy.

SUBSTANCE: inventions relate to the treatment of metals by pressure and can be used in the production of hot-rolled seamless pipes with simultaneous treatment of the liner inner surface and the tool working surface with a lubricating-deoxidizing product. Method includes deforming the heated blank with working rolls on a rotating mandrel mounted on a rod through an adapter, and feeding a phosphate components based lubricating-deoxidizing product (LDP) on it with the inactive gas stream. LDP is fed after filling the deformation focus at an acute angle, which can be 2÷35° to the longitudinal axis of the blank in the direction opposite to the direction of piercing, and continue feeding the inactive gas after the deformation focus release. Device comprises working rolls, a mandrel mounted on a rod through an adapter, a LDP with an inactive gas stream supplying unit, tightly connected to the adapter, and the cooling unit. Adapter is made with outlet ducts, which axes in the longitudinal section of the adapter are located at an acute angle to the longitudinal axis of the mandrel and are oriented in the direction of the mandrel. Adapter is made to enable prevention of the cooling medium ingress to the outlet ducts.

EFFECT: use of inventions increases the quality of the sleeves inner surface and the resistance of the piercing mill mandrels.

5 cl, 3 dwg, 1 tbl