Forming Flashcards
What’s the difference between forging hammers and forging press?
Hammers: force applied by falling weight
Press: slow-speed compression (mechanical and hydraulic)
Types of forging
a. open die: pre-forming step performed between flat dies for final forging
b. closed die: work-piece deformed between two halves of mold of final shape
What does the pressure applied on the workpiece depend on?
a. roll radius R
b. coefficient of friction μ
c. reduction in thickness Lo-L
d. flow strength of metal σflow
What factors of rolling geometry can we control?
roll diameter, flow strength, coefficient of friction
As Pavg/σo increases, what happens to μ and a/h?
μ increases; a/h increases
What happens at the neutral point?
velocity of sheet = velocity of rolls
The volume rate of metal flow is ______
constant; voho = vh = vfhf
As σo ↑, R (or Lp) ↑, μ ↑, the average pressure for rolling _____
increases