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CAST IRON
CAST IRON
Cast Iron is generally defined as an alloy of Iron with 2 to 4.5% Carbon, and usually with more than 0.1% Silicon
The three main ingredients are IronCarbonSilicone
Cast iron containing more of these materials than steel.
TYPES OF CAST IRON
1)-Grey cast iron - carbon as graphite
2)-White cast iron – carbides
3)-Ductile cast iron nodular, spheroidal graphite
4)-Malleable cast iron
GREY CAST IRON Graphite flakes surrounded by a
matrix of either Pearlite or -a Ferrite
Wide range of applications Low ductility Grey cast iron forms when
Cooling is slow, as in heavy sections
GREY CAST IRON
APPLICATIONS
Engines Pressure pipe fittings Machinery beds Furnace parts
WHITE CAST IRON No graphite, because carbon forms Fe3C
or more complex carbides Large amount of carbide phases in
the form of flakes, surrounded by a matrix of Pearlite
The absence of graphite causes white iron's light-colored appearance
WHITE CAST IRON
APPLICATIONS
Stairs Decorative features Tools and utensils
DUCTILE IRON Inoculation with Mg causes graphite to
form as spherulites, rather than flakes
Also known as spheroidal graphite (SG).
Far better ductility than grey cast iron
DUCTILE IRON
APPLICATIONS
Automotive industry 55% of ductile iron used
Crankshafts
front wheel spindle supports
steering ; disc brake callipers
Pipe and pipe fittings (joined by welding)
MALLEABLE IRON
Graphite in nodular form
Produced by heat treatment of white cast iron
Graphite nodules are irregular clusters
Similar properties to ductile iron
MALLEABLE IRON
APPLICATIONS
Similar applications to ductile iron
Malleable iron is better for thinner castings
Vehicle components
Railway components
Pipe fittings
ANY QUESTION……???????
