Cast iron is manufactured in
Blast furnace
Cupola
Open hearth furnace
Bessemer converter
Correct Answer :
B. Cupola
Related Questions
Addition of manganese to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
Hardness of martensite is about
RC 65
RC 48
RC 57
RC 80
The temperature required for full annealing in hypereutectoid steel is
30°C to 50°C above upper critical temperature
30°C to 50°C below upper critical temperature
30°C to 50°C above lower critical temperature
30°C to 50°C below lower critical temperature
When low carbon steel is heated up to upper critical temperature
There is no change in grain size
The average grain size is a minimum
The grain size increases very rapidly
The grain size first increases and then decreases very rapidly
The hardness of steel increases if it contains
Austenite
Martensite
Pearlite
Cementite
Shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Sulphur, lead and phosphorus
The carbon in the pig iron varies from
0.1 to 0.5 %
0.5 to 1 %
1 to 5 %
5 to 10 %
Materials after cold working are subjected to following process to relieve stresses
Hot working
Tempering
Normalising
Annealing
Shock resisting steels should have
Low wear resistance
Low hardness
Low tensile strength
Toughness
The brown smoke during the operation of a Bessemer converter indicates that the
Air is burning out silicon and manganese
Silicon and manganese has burnt and carbon has started oxidising
The converter must be titled to remove the contents of the converter
The brown smoke does not occur during the operation of a Bessemer converter
Gun metal contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 78% copper and rest tin
Blast furnace produces following by reduction of iron ore
Cast iron
Pig iron
Wrought iron
Malleable iron
Which of the following constituents of steels is softest and least strong?
Austenite
Pearlite
Ferrite
Cementite
A small percentage of boron is added to steel in order to
Increase hardenability
Reduce machinability
Increase wear resistance
Increase endurance strength
Compressive strength of grey cast iron in tonnes/cm is of the order of
35
57
710
1015
The defect which takes place due to imperfect packing of atoms during crystallisation is known as
Line defect
Surface defect
Point defect
None of these
Sulphur in cast iron
Makes the iron soft and easily machinable
Increases hardness and brittleness
Make the iron white and hard
Aids fusibility and fluidity
Weld decay is the phenomenon found with
Cast iron
Mild steel
Nonferrous materials
Stainless steel
Foundry crucible is made of
Mild steel
German silver
Lead
Graphite
An engineer's hammer is made of
Cast iron
Forged steel
Mild steel
High carbon steel
Babbitt metal is a
Lead base alloy
Tin base alloy
Copper base alloy
Both (A) and (C) above
Annealing of white cast iron results in production of
Malleable iron
Nodular iron
Spheroidal iron
Grey iron
Which is false statement about normalizing? Normalizing is done to
Refine grain structure
Reduce segregation in casting
Improve mechanical properties
Induce stresses
White cast iron has
Carbon in the form of carbide
Low tensile strength
High compressive strength
All of these
In induction hardening ________ is high.
Current
Voltage
Frequency
Temperature
Tungsten when added to steel ________ the critical temperature.
Does not effect
Lowers
Raises
None of these
White cast iron
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 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
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
The percentage of carbon in grey iron castings usually varies between
0.5 to 1 %
1.2 %
2.5 to 4.5 %
5 to 7 %
Hardness of lower bainite (tempered martensite) is about
RC 65
RC 48
RC 57
RC 80