TUBE LENGTHWISE ROLLING METHOD Russian patent published in 2007 - IPC B21B17/04 

FIELD: rolled tube production, namely processes for rolling tubes on mandrel with use of technological lubricant.

SUBSTANCE: method comprises steps of deforming heated sleeve on mandrel by means of grooved rolls and supplying to it before rolling melting lubricating material; distributing said lubricating material on inner surface of sleeve while using composition of said melting lubricating material that provides its complete melting before start of rolling process. Time period of complete melting of lubricating material corresponds to time interval of sleeve motion from time moment of supplying melting lubricating material till moment of starting lengthwise rolling process due to selected composition and physical-chemical properties of said material. Meta- and poly-phosphates of alkali metals with additives are used as melting lubricating material. Boric acid, sodium tetra-borate, boric acid anhydride are used as additives. It is possible to use as melting lubricating material sodium polyphosphate with boric acid as additive.

EFFECT: increased strength of mandrels, improved quality of inner surface of tubes.

3 cl