An open forging die used to forge a cylindrical part with theinitial diameter is 45 mm and the initial height is 40 mm. Thecoefficient of friction at the die-work interface is 0.20. Theheight after forging is 25 mm. The yield strength of the workmaterial is 285 MPa, and its flow curve is defined by a strengthcoefficient of 600 MPa and a strain-hardening exponent of 0.12.Determine the force in the operation (a) just as the yield point isreached (yield at strain = 0.002), (b) at a height of 35 mm, (c) ata height of 30 mm, and (d) at a height of 25 mm.
