forging Flashcards
what is forging
work piece compressed between two dies, makes variety of high strength components
what parts are made from forging
engine crankshafts, connecting rods, gears, aircraft structural components, jet engine turbine parts.
forging equipment?
forging hammer - machine that applies impact load
forging press - machine that applies gradual pressure
difference between forging hammer and press
forging presses apply gradual pressure rather than sudden impact
main forging operations
open die forging (work compressed between two flat dies. metal flows without constraint)
impression-die forging (die surfaces contain shape, there is metal to be trimmed off later tho)
flashless forging (work completely constrained within die, no excess flash produced)
what is parting line in forging die
plane that divides upper from lower die
what is draft in forging dies
amount of taper on sides of part required to remove from die
what are webs and ribs in forging die
thin portions that are parallel (web) and perpendicular (rib) to parting line
why have fillet and corner radii in die
small radii limit metal flow, increase stresses on die surfaces
upset forging
cylindrival workpart increased in diameter, reduced in length. for heads on bolts, nails, similar.
roll forging
combines rolling and forging, used for short bars
advantages and disadvantages of forging
pros: material properties improved. fairly complicated shapes can be produced
cons: high cost, low production rate
