This document discusses the effects of various metal forming processes like rolling, forging, extrusion, wire drawing, and deep drawing on metallurgical structures. It explains the key characteristics of each process and their effects. Specifically, it notes that forming processes can result in preferred orientation, development of deformation bands and texture in rolled sheets. The speed of deformation affects flow stress and temperature. Friction and lubrication impact subshear zone formation. Finally, residual stresses from non-uniform plastic deformation are generated, with compressive stresses at surfaces and tensile stresses in the center.

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