Date post: | 03-Jun-2018 |
Category: |
Documents |
Upload: | prihatmokoadinugroho |
View: | 218 times |
Download: | 0 times |
of 13
8/12/2019 Ferrous Metal Shaping
1/13
FERROUS METALS
8/12/2019 Ferrous Metal Shaping
2/13
They are first cast into simple shapes, ingot
Later ingots are given a preliminary shapingby being rolled or forged into billets. Finally, desired shapes are obtained frombillets by: Forging Rolling Extrusion
Drawing
Shaping Structural Steel
8/12/2019 Ferrous Metal Shaping
3/13
FORGING
Place a billet in a die and apply
pressure with a suitably shapedpunch.
As the metal is forced into position, it is stressed
above the proportional limit and refinement ingrain boundaries or goes into strain hardening.Thick plates, sheetings and objects of irregular
shape are produced by forging.
8/12/2019 Ferrous Metal Shaping
4/13
ROLLING
8/12/2019 Ferrous Metal Shaping
5/13
Hot Rolling: If the temperature of themetal is above its critical temperaturewhich causes recrystallization of thecrystallic structure. Properties will not beaffected greatly.
Cold Rolling: If the temperature is belowthe critical temperature the initial crystallic
structure will be maintained but theproperties will change. The strength isincreased but the ductility is decreased.
8/12/2019 Ferrous Metal Shaping
6/13
EXTRUSION
Applying sufficient pressure to thematerial by forcing it through a die whichhas the required constant cross-section(I-beams, channel section)
8/12/2019 Ferrous Metal Shaping
7/13
DRAWING
A rolled rod is pulled through a diehaving an opening smaller than the original
cross-section of the rod. Wires and somerods are prepared by this method.
8/12/2019 Ferrous Metal Shaping
8/13
FACTORS THAT AFFECTPROPERTIES OF STEELS
Carbon contentHeat treatment and shaping method
Presence of harmful elementsPresence of alloying materials.
8/12/2019 Ferrous Metal Shaping
9/13
Carbon Content
For steel C ~0.05-2% usually
8/12/2019 Ferrous Metal Shaping
10/13
Carbon Content
8/12/2019 Ferrous Metal Shaping
11/13
Cold Drawn & Cold Rolled Nomicrostructural changes. Changes are
plastic deformations in the form ofelongation of grains.Hot Rolled Microstructural changes
Drawn & Annealed Initial stresses arereleaved.
Heat Treatment andShaping Methods
8/12/2019 Ferrous Metal Shaping
12/13
Heat Treatment andShaping Methods
8/12/2019 Ferrous Metal Shaping
13/13
Alloying Elements
Alloying elements are added to steel: Higher strength with ductility
Higher resistance to corrosion Higher resistance to heat
Chromium & Nickel are the most important
alloying elements. Stainless Steel has~20% Chromium & 8% Nickel.