METHOD OF MANUFACTURING LARGE-SIZE FORGINGS OF HALF-CASES OF BALL VALVES Russian patent published in 2019 - IPC B21K21/08 

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used in production of all-metal parts of pipeline valves, for example, large-size semi-cases of ball valves. Perform heating of initial workpiece in the form of shell with external diameter equal to 0.80÷0.85 of forged piece maximum diameter in hemisphere zone, and with thickness equal to 1.12÷1.15 of forging wall thickness in hemisphere zone. First, first heating is performed to t°=750÷800 °C throughout the volume, and then in the induction heater part of the workpiece is heated in the formation zone of the neck to t°=950÷1,150 °C. Workpiece is folded to form a neck and then distributed to form a hemisphere. During formation of neck workpiece is subjected to thickening. Then part of workpiece is heated in induction heater in zone of semi-sphere formation and its distribution is performed with thinning.

EFFECT: disclosed is method of making large-size forgings of half-cases of ball valves.

1 cl, 2 dwg, 1 tbl, 1 ex