MANDREL PIERCING MILL AND METHOD OF ITS MANUFACTURE Russian patent published in 2019 - IPC B21B25/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy and can be used in mandrels for piercing workpieces with production of hollow sleeves and their rolling in production of seamless steel pipes. Mandrel comprises nose and body, nose is made of cermet in form of interpenetrating matrices based on titanium carbide and binder in form of alloy based on intermetallide Ni₃Al in amount of 25–70 vol%, and housing – from alloy based on intermetallic compound Ni₃Al or alloyed steel, wherein on one end surface of nose there are slots filled with alloy based on Ni₃Al intermetallide, forming transition layer, to the surface of the transition layer there is a buffer layer of alloy based on intermetallide Ni₃Al, and the surface of the buffer layer is adjoined by a housing metallurgically connected to the buffer layer by means of a welding seam from nickel alloy, wherein the nose, the transition layer and the buffer layer are metallurgically connected to each other.

EFFECT: longer service life of piercing mill mandrel when making seamless steel pipes.

10 cl, 5 dwg