Engineering Materials
Chromium in steel

Gives ductility, toughness, tensile strength and anti-corrosion properties
Improves cutting ability and reduces hardenability
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties

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Engineering Materials
White cast iron

Is produced by annealing process. It is soft, tough and easily machined metal
Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material

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Engineering Materials
Points of arrest for iron correspond to

Stages at which properties do not change with increase in temperature
There is nothing like points of arrest
Stages at which further heating does not increase temperature for some time
Stages at which allotropic forms change

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