METHOD OF RIFLED BORE FABRICATION Russian patent published in 2009 - IPC B21K21/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to pressurised metal treatment for producing rifled stepped bores. The fabrication method of rifled bore includes production of original work piece, hardening thermal treatment, mechanical treatment to the dimensions of pipe work piece for radial squeezing, forged piece production in two radial squeezing operations. As a result, plain channel is formed in forged piece during radial pre-squeezing operation, and threaded channel is formed in forged piece during the final radial squeezing and mechanical treatment operations. During rifled bore fabrication, the pipe work piece is subject to hardening thermal treatment after mechanical treatment but before the first squeezing operation, or forged piece is subject to hardening thermal treatment after the first squeezing operation.

EFFECT: reduced manpower effort, material and energy costs, and reduced consumption of tools and deterioration of used equipment during operations preceding final radial squeezing of forged piece.