2. Definition : Forging is process of plastically
deforming metal or alloy to a specific shape
by a compressive force exerted by some
external agency like hammer, press, rolls,or
by an upsetting machine of some kind.
3.
Forging is manufacturing process where
metal is pressed, pounded or squeezed
under great pressure into high strength
parts known as forgings. The process is
normally (but not always) performed hot by
preheating the metal to a desired
temperature before it is worked. It is
important to note that the forging process is
entirely different from the casting (or
foundry) process, as metal used to make
forged parts is never melted and poured
(as in the casting process).
4. History of Forging:
Forging is one of the oldest known
metalworking
processes.
Traditionally,
forging was performed by a smith using
hammer and anvil, and though the use of
water power in the production and working
of iron dates to the 12th century, the
hammer and anvil are not obsolete. The
smithy or forge has evolved over centuries
to become a facility with engineered
processes, production equipment, tooling,
raw materials and products to meet the
demands of modern industry.
5. In modern times, industrial forging is done
either with presses or with hammers
powered by compressed air, electricity,
hydraulics or steam. These hammers may
have reciprocating weights in the thousands
of pounds. Smaller power hammers, 500 lb
(230 kg) or less reciprocating weight, and
hydraulic presses are common in art smithies
as well. Some steam hammers remain in
use, but they became obsolete with the
availability of the other, more convenient,
power sources.
6. Classification of Forging
1. Smith die forging
• a. Hand forging
• b. Power forging
• Hammer forging
• Press forging
2.impression-die forging
• a.Drop forging
• b.Press forging
• c.Machine forging
7. 1. Smith die forging (open-die)
Smith forging, also called flat-die forging and
open die forging.
8. The final shape of the forging depends on skill of smith
or size and shape
Smith forging, done by hand on an anvil, is employed
only to shape a small number of light forging.
Heavy forgings weighing up to 25,000 kg as well as
medium forgings in small batches, are produced
exclusively in hammers and presses
9. Open-Die Forging with No Friction
(1) Start of process with work-piece at
its original length and diameter,
(2) partial compression, and
(3) final size
10. Open-Die Forging with Friction
Actual deformation of a cylindrical work
part in open-die forging, showing
pronounced barreling:
(1) start of process,
(2) partial deformation, and
(3) final shape
12.
More complex shape of greater
accuracy can be formed by impression
die forging techniques
Large quantities of identical forging of
greater accuracy are required as is
necessary
in
mass
production
impression die forging are commonly
use.
13.
14.
Compression of work part by dies with inverse of
desired part shape
• Flash is formed by metal that flows beyond die
cavity into small gap between die plates
• Flash must be later trimmed, but it serves an
important function during compression:
– As flash forms, friction resists continued metal
flow into gap constraining metal to fill die cavity
15. Advantages and Limitations of
Impression-Die Forging
Advantages :
– Higher production rates
– Less waste of metal
– Greater strength
– Favorable grain orientation in the metal
Limitations:
– Not capable of close tolerances
– Machining is often required to achieve
accuracies and features needed.
16. Applications of forging:
connecting rods
crankshafts
wheel spindles
axle beams
pistons, gears, and steering arms
Automotive and Truck
Aerospace
Agricultural
Valves and Fittings
Industrial, Hardware and Tools
