Engineering Materials
Ductile cast iron

Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Is produced by annealing process. It is soft, tough and easily machined metal
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
Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron

ANSWER DOWNLOAD EXAMIANS APP

Engineering Materials
Chromium in steel

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

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Engineering Materials