Alloying Elements And Their Properties
🔗Different types of cast iron and their properties
Specific alloy elements and quantities determine the type of steel alloy and their particular properties.
Specific alloy elements and quantities determine the type of steel alloy and their particular properties.
The main effects of some of the most common elements are:
ALUMINUM
|
Used in small amounts; it acts
as a deoxidizer
for molten steel.
Produces a fine
Grain Steel (by limiting the growth of
austenite grains).
Promotes nitriding.
|
BORON
|
|
CHROMIUM
|
Increase hardness.
Improves wear, abrasion, corrosion resistance.
|
COBALT
|
Increase tempering resistance at high temperatures.
Cobalt is often
used in high-speed steels.
|
COPPER
|
A significant increase in corrosion resistance.
Improve formability & machinability.
Counteracts brittleness due to sulphur.
|
LEAD
|
Lead is not
combined with steel; it is in
the form of tiny inclusion.
Significantly improve machinability.
|
MANGANESE
|
The primary element in all commercial steels. It acts as a
deoxidizer and also neutralizes the harmful effects of sulphur.
Improve hardenability, strength at high
temperature.
Increase carbon penetration during
carburization.
Reduce weldability and ductility.
|
MOLYBDENUM
|
Increases the toughness and strength at high
temperatures.
Protection from corrosion caused by chloride
and sulphur.
Used in HSS cutting tool, high-pressure cylinders, turbine rotor.
|
NICKEL
|
Promote an austenitic microstructure.
When used in conjunction with chromium, it
increases the hardness and toughness.
Resistance to corrosion and oxidization.
|
NITROGEN
|
Add in some steel
to promote the formation of austenite.
Improves yield strength.
|
PHOSPHORUS
|
At higher rates, phosphorus reduces ductility,
thereby increasing the tendency of the steel to crack when working in the cold.
Improves machinability in free-cutting steels.
Used in spring steels.
|
SILICON
|
Promotes a ferritic microstructure.
Larger grain sizes
Leading to greater magnetic
permeability.
Improves strength, elasticity.
Increase hardenability.
It is used
as a deoxidizer.
|
SULPHUR
|
Usually an impurity and maintained at a low
level. However, sometimes intentionally added in large amounts (from 0.06 to
0.30%) to increase the machinability of alloy steels.
|
TITANIUM
|
It is used to inhibit grain growth.
High temperature strength.
Increase resistance to oxidization.
|
TUNGSTEN
|
Increase pitting corrosion resistance.
To improve heat resistance.
It is used
in alloy tool steels.
|
VANADIUM
|
Helps in the formation of fine grain size.
It increases strength and also the fatigue strength.
Increases tempering resistance.
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