Ferrous and non ferrous alloys

FERROUS
AND
NON-FERROUS ALLOYS
Unit – 7

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Ferrous: Iron based alloys
Non-ferrous: other than ferrous alloys with no iron content

FERROUS METALS AND ALLOYS
What is a ‘ferrous metal’ or ‘ferrous alloy’?  It is simply a metal or alloy that contains Iron (the element ferrous) as the base (starting) metal.
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 26th element 
Iron or Ferrous 
55.85 Atomic
Mass

GENERAL CATEGORIES OF FERROUS
METALS AND ALLOYS
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Carbon and alloy steels
Stainless steel
Tool and Die steel
Cast Irons
Cast Steels
 **Ferrous tools first appear about 4000 to 3000 BC, made from meteoritic iron.
 Real ironworking started in about 1100
BC in Asia Minor, and started the Iron
Age.

PRODUCTION OF IRON AND
STEEL

RAW MATERIALS FOR PRODUCTION

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Iron Ore

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Limestone ----------

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Coke

IRON ORE

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Abundant, makes up 5% of earth’s crust
Is not found in ‘free state’, must be found in rocks and oxides, hence Iron ore.
After mining, the ore is crushed and the iron is separated, then made into pellets, balls or briquettes using binders, such as water.
The pellets are typically 65% iron, and about 1” in diameter.

COKE – (…THE BLACK, LEGAL KIND)



Coke is formed by heating coal to 2100*F (1150
C), then cooling it in quenching towers.

You need more than Iron? Why coke is used… 1. Generates high heat, needed in order for chemical reactions in iron making to take place.
2. Produces CO (carbon monoxide) which reduces iron-oxide to Iron.

LASTLY, LIMESTONE

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Limestone (calcium remove impurities.
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carbonate)

is

used

to

When the metal is melted, limestone combines with impurities and floats to the top of the metal, forming slag.
The slag can then be removed, purifying the iron. Ferrous alloys can be broadly classified into 2 groups:
1. Steels (C% is <2.1)
2. Cast iron (C% is >2.1-6.67)
Steels have carbon in the combined form (austenite, cementite etc.)
Cast irons have carbon in the free form as graphite
These ferrous alloys are not only iron and carbon