Forming

Question 1

What’s the difference between forging hammers and forging press?

Answer 1

Hammers: force applied by falling weight
Press: slow-speed compression (mechanical and hydraulic)

Question 2

Types of forging

Answer 2

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

Question 3

What does the pressure applied on the workpiece depend on?

Answer 3

a. roll radius R
b. coefficient of friction μ
c. reduction in thickness Lo-L
d. flow strength of metal σflow

Question 4

What factors of rolling geometry can we control?

Answer 4

roll diameter, flow strength, coefficient of friction

Question 5

As Pavg/σo increases, what happens to μ and a/h?

Answer 5

μ increases; a/h increases

Question 6

What happens at the neutral point?

Answer 6

velocity of sheet = velocity of rolls

Question 7

The volume rate of metal flow is ______

Answer 7

constant; voho = vh = vfhf

Question 8

As σo ↑, R (or Lp) ↑, μ ↑, the average pressure for rolling _____

Answer 8

increases