How the Metallurgical structures may be effected due to Forming can be studied.

1. EFFECT OF METALLURGICAL
STRUCTURES DUE TO FORMING
BY
B.VISHNU VARDHAN
METALLURGY & MATERIAL SCIENCES
YSR ENGINEERING COLLEGE OF YOGI VEMANA UNIVERSITY
PRODDATUR

2. FORMING PROCESS
• Rolling
• Forging
• Extrusion
• Wire drawing
• Deep drawing

3. ROLLING
• The process of plastically deforming
metal by passing it between rolls is
known as Rolling
• Most widely used metal working
process
• Two types of rolling processes viz. Hot
rolling and cold rolling
• Hot rolling - Breakdown of ingots into
billets
• Cold rolling – Ground and polished for
good finish

4. FORGING
• Forging is the working of metal into a
useful shape by hammering or pressing
• It has capable of making parts in size
from Bolt to turbine rotar/airplane wing
• Two types of Forging processes viz.Open-
die forging and closed-die forging
• Open-dies are of simple shape
• Close-dies has two die halves which
carry the impressions of the desired final
shape

5. EXTRUSION
• The process by which a block of metal is
reduced in cross section by forcing it to
flow through a die orifice under high
pressure
• Used to produce cylindrical bars/hollow
tubes
• Two types of extrusion processes viz.
Direct and Indirect extrusion

6. WIRE DRAWING
• The reduction in diameter of a
solid bar or rod by successive
drawing is known as
bar/rod/wire drawing
• Basically it is a cold working
process
• It depends on the diameter of
the final product
• Usually carried at room
temperature
• Tungsten carbide dies are used
for drawing hard wires
whereas diamond dies for fine
wires

7. DEEP DRAWING
• A flat sheet metal blank is formed
into a hollow body open on one
side with a small cross section
• It is performed with a punch and
die
• It is a combination of tensile and
compressive stresses
• Used for making cylindrical shaped
parts viz.cups,shells from sheet
metal

8. EFFECTS ON METALLURGICAL STRUCTURES
• The presence of preferred
orientation causes anisotropy of
mechanical properties especially in
rolled sheets
• The development of texture is the
formation of deformation bands
which are regions of distortion where
a portion of grains have rotated
towards another orientation to
accommodate the applied strain

9. EFFECT OF SPEED OF DEFORMATION
• High flow stress
• Increased the temperature of the workpiece
• Improved lubrication at the metal interface

11. EFFECT OF FRICTION AND
LUBRICATION
• When two surfaces are brushed into contact,the high spot
will come into contact
• As we increases the load, the metal at the high spots deform
plastically and produce subshear zone
• The coefficient of friction is given by mu=F/P where F is
shearing force and P is stress normal to interface

13. EFFECT OF RESIDUAL STRESSES
• Residual stresses is generated by
non-uniform plastic deformation
when external stresses are
removed
• High compressive stress at surface,
tensile stress in the center
• Due to continuity of sheet, central
fibres tend to restrain the surface
fibres from elongating while the
surface fibres tend to strengthen
the central fibres

14. Thank you