Forging

Question 1

Typical Forged Parts

Answer 1

Shafts, gears, turbine blades

Question 2

Forging Process

Answer 2

A basic process in which the work piece is shaped by compressive forces applied through various dies and tooling

Question 3

Cold vs. Hot Forging

Answer 3

• Cold forging requires higher forces, work piece must have higher ductility
• Cold forged parts have good surface finish and accuracy

Question 4

Advantages Forging vs. Machining

Answer 4

• Higher production rates
• Conservation of metal
• Greater strength
• Favorable grain orientation

Question 5

Open Die Forging

Answer 5

Simplest Form of Forging

- A solid work piece is placed between two flat dies and reduced in height by compressing it

Question 6

Progressive Forging

Answer 6

for- and backwards while hammering (cogging)

Question 7

Step forging

Answer 7

turns while hammering (rotate)

Question 8

Impression die Forging

Answer 8

Workpiece takes the shape of the die cavity while being forged between two shaped dies

Question 9

Whats flash (Impression die forging?)

Answer 9

little pieces of metal that goes in narrow spaces of die

Question 10

Is flash good?

Answer 10

yes, it allows more deformation of the workpiece because of higher pressure control

Question 11

Die Inserts

Answer 11

Insert for Dies of different material, which needs to be very hard
outside structure--> best toughness
inside structure--> best strength
- exchangably seperatly
- more detailed shape possible
- work harder material

Question 12

Forging Terminology

Answer 12

• Fullering: Material is distributed away from an area
• Edging: Material is gathered into a localized area
• -> both to get workpiece in shape which is closer to final shape
• Blocking: Part is formed into a rough shape using blocker dies
• Finishing: Impression dies give the forge the final shape
• Trimming: Flash is removed

Question 13

Precision and Flashless Forging

Answer 13

• Very Expensive tools
• long life cylce necassary
• greater precision
• more complex dies
• high amount of quantity that its worth it

Question 14

Other Forging processes

Answer 14

• Heading (Schrauebenkopf formen)
• -> shape of head can be in punch or/and in die
• Coining (Münzen)
• -> cold forming
• Swaging
• ->process where a solid rod or hollow tube is subjected to radial impact forces by a set of reciprocating dies

Question 15

When is forging economical?

Answer 15

large amount of quantity (because of high Tooling cost); little amount of quantity –> casting