METHOD OF SHELL MANUFACTURING OUT OF CAST BLANK Russian patent published in 2010 - IPC B21B19/04 

FIELD: metallurgy.

SUBSTANCE: invention is intended for improvement of quality and precision of dimensions in helical broach of cast material shells. Method involves processing in double-roller mill of helical rolling with heated blank capture by turning rollers featuring inlet cone, nip and outlet cone, blank clamping along diametre in the inlet cone, and broaching by mandrel. Intensive non-destructive processing of metal structure with obtainment of tubes of high dimensional precision and high inner and outer surface quality is achieved by implementation of clamping within 3-7 half-turns of blank in the inlet cone before mandrel, with mean clamping value of 0.4-2% per half-turn, and clamping force increase by 2-3 times at further half-turns, where the number of half-turns is defined by mathematical relation.

EFFECT: improved quality and precision of dimensions.

2 cl, 1 ex