PIERCING MILL AND METHOD OF MANUFACTURING SEAMLESS METAL PIPE USING A PIERCING MILL Russian patent published in 2021 - IPC B21B45/02 B21B19/04 

FIELD: piercing mill.

SUBSTANCE: mill contains a plurality of skewed rolls, a mandrel located on the passage line between the plurality of skewed rolls, a mandrel rod, an outer surface cooling mechanism for cooling the outer surface of the hollow billet, and a front guard mechanism. The front guard mechanism contains a mechanism that, when the outer surface cooling mechanism cools the hollow billet in the cooling zone by releasing the cooling fluid to the upper section of the outer surface, to the lower section of the outer surface, to the left section of the outer surface and to the right section of the outer surface of the hollow billet, provides a barrier to the flow of the cooling fluid to the upper section of the outer surface, the lower section of the outer surface, the left section of the outer surface and the right section of the outer surface of the hollow billet before the hollow billet enter the cooling zone.

EFFECT: reduced temperature difference between the front-end section and the back end section of the hollow billet.

15 cl, 33 dwg