In malleable iron, carbon is present in the form of
Cementite
Free carbon
Flakes
Nodular aggregates of graphite
Correct Answer :
D. Nodular aggregates of graphite
Related Questions
The electric process of steel making is especially adapted to
Alloy and carbon tool steel
Magnet steel
High speed tool steel
All of these
The crystal structure of brass is
F.C.C.
B.C.C.
H.C.P.
Orthorhombic crystalline structure
Weld decay is the phenomenon found with
Cast iron
Mild steel
Nonferrous materials
Stainless steel
The alloy, mainly used for corrosion resistance in stainless steels is
Silicon
Manganese
Carbon
Chromium
Railway rails are normally made of
Mild steel
Alloy steel
High carbon
Tungsten steel
Heavy duty leaf and coil springs contain carbon of the following order
0.2 %
0.5 %
0.8 %
1.0 %
White cast iron contains carbon in the form of
Free carbon
Graphite
Cementite
White carbon
Perminvar alloy having constant permeability is an alloy of
Nickel, copper and iron
Nickel, copper and zinc
Copper, nickel and antimony
Iron, zinc and bismuth
Iron-carbon alloys containing 1.7 to 4.3% carbon are known as
Eutectic cast irons
Hypoeutectic cast irons
Hypereutectic cast irons
None of these
The most effective inhibitor of grain growth, when added in small quantities is
Carbon
Vanadium
Manganese
Cobalt
Paramagnetic alpha iron changes to gamma iron at
770°C
910°C
1440°C
1539°C
A cold chisel is made of
Mild steel
Cast iron
HSS
High carbon
Malleable cast iron is produced
By adding magnesium to molten cast iron
By quick cooling of molten cast iron
From white cast iron by annealing process
None of these
In process annealing, the hypo eutectoid steel is
Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
Heated below or closes to the lower critical temperature and then cooled slowly
Nickel when added to copper improves
Machinability
Hardness
Hardness and strength
Strength and ductility
Mild steel belongs to the following category
Low carbon steel
Medium carbon steel
High carbon steel
Alloy steel
A specimen of aluminium metal when observed under microscope shows
B.C.C. crystalline structure
F.C.C. crystal structure
H.C.P. structure
A complex cubic structure
The carbon in the pig iron varies from
0.1 to 0.5 %
0.5 to 1 %
1 to 5 %
5 to 10 %
Which of the following statement is incorrect about duralumin?
It is prone to age hardening
It can be forged
It has good machining properties
It is lighter than pure aluminium
The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
770°C
910°C
1050°C
Below recrystallisation temperature
Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio
50 : 50
30 : 70
70 : 30
40 : 60
Delta metal is an alloy of
Copper, zinc and iron
Iron, nickel and copper
Iron, lead and tin
Iron, aluminium and magnesium
Cupola produces following material
Cast iron
Pig iron
Wrought iron
Malleable iron
If a refractory contains high content of silicon, it means refractory is
Acidic
Basic
Neutral
Brittle
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
Monel metal is an alloy of
Nickel and copper
Nickel and chromium
Nickel, Chromium and iron
Copper and chromium
Which is the false statement about wrought iron? It has
High resistance to rusting and corrosion
High ductility
Ability of hold protective coating
Uniform strength in all directions
Which of the following is not the correct method of increasing fatigue limit?
Shot peening
Nitriding of surface
Cold working
Surface decarburisation
The molecules in a solid move
In a random manner
In a haphazard way
In circular motion
Back and forth like tiny pendulums
The material in which the atoms are arranged chaotically, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these