METHOD OF FORGING LARGE-SIZED HALF-BODIES OF BALL VALVES WITH THROAT AND SPHERICAL PART Russian patent published in 2013 - IPC B21K21/10 

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and may be used in forging large-sized half-bodies of ball valves from spun-cast and forged pipe billets. The billet is heated to 1150-1200°C and deformed. First, semi-finished product is directly extruded at high temperature to thickness smaller than that of initial billet by 25-30% and equals that of forged piece spherical part. Then after heating semi-finished product is stamped in second mould with spherical bottom male die. Note here that semi-finished product is simultaneously reduced and expanded to obtain the throat and the spherical part. Semi-finished product is expanded at said spherical bottom male die with OD increase by, at least, 10%. Thus, in fact all metal of pipe billet is subjected to plastic strain without breakage in uniformity.

EFFECT: lower costs and metal input, higher mechanical properties and process efficiency.

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