When steel containing less than 0.8% carbon is cooled slowly from temperatures above or within the critical range, it consists of
Mainly ferrite
Mainly pearlite
Ferrite and pearlite
Pearlite and cementite
Correct Answer :
C. Ferrite and pearlite
Related Questions
Which of the following has highest specific strength of all structural materials?
Magnesium alloys
Titanium alloys
Chromium alloys
Magnetic steel alloys
German silver contains
1% silver
2% silver
5% silver
No silver
The heat treatment process used for softening hardened steel is
Carburising
Normalising
Annealing
Tempering
The aluminium alloy, mainly used, for anodized utensil manufacture, is
Duralumin
Y-alloy
Magnalium
Hindalium
White cast iron contains carbon in the form of
Free carbon
Graphite
Cementite
White carbon
The ability of a material to absorb energy in the plastic range is called
Resilience
Creep
Fatigue strength
Toughness
Nickel in steel
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
Improves cutting ability and reduces hardenability
Gives ductility, toughness, tensile strength and anticorrosion properties
Pure iron is the structure of
Ferrite
Pearlite
Austenite
Ferrite and cementite
The percentage carbon content in wrought iron is about
0.02
0.1
02
0.4
Which of the following elements does not impart hardness to steel?
Copper
Chromium
Nickel
Silicon
In induction hardening ________ is high.
Current
Voltage
Frequency
Temperature
Cold rolled steel sheets contain carbon of the following order
0.1 %
0.2 %
0.4 %
0.6 %
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
Increase
Decrease
Remain same
First increase and then decrease
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
Cast iron is manufactured in
Blast furnace
Cupola
Open hearth furnace
Bessemer converter
The lower critical temperature
Decreases as the carbon content in steel increases
Increases as the carbon content in steel increases
Is same for all steels
Depends upon the rate of heating
The surface hardness of the following order is achieved by nitriding operation
600 VPN
1500 VPN
1000 to 1100 VPN
250 VPN
The correct composition of Babbitt metal is
87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
87% Sn, 4% Cu, 8% Sb, 1% Al
82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg
Delta iron occurs at temperature of
Room temperature
Above melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
Nickel when added to copper improves
Machinability
Hardness
Hardness and strength
Strength and ductility
Steel made from phosphate iron is
Brittle
Hard
Ductile
Tough
In basic Bessemer process, the furnace is lined with
Silica bricks
A mixture of tar and burnt dolomite bricks
Both (A) and (B)
None of these
Chromium when added to steel __________ the tensile strength.
Does not effect
Decreases
Increases
None of these
Combined carbon in iron makes the metal
Soft and gives coarse grained crystalline structure
Soft and gives a fine grained crystalline structure
Hard and gives a coarse grained crystalline structure
Hard and gives a fine grained crystalline structure
Lead is poured into the joint between two pipes. These pipes may be made of
Cast iron
Vitrified clay
Asbestos cement
Concrete
Normalising of steel is done to
Refine the grain structure
Remove strains caused by cold working
Remove dislocations caused in the internal structure due to hot working
All of the above
Phosphor bronze contains
0.5% of phosphorous
1% phosphorous
2.5% phosphorous
None of the above
Free carbon in iron makes the metal
Soft and gives a coarse grained crystalline structure
Soft and gives a fine grained crystalline structure
Hard and gives a coarse grained crystalline structure
Hard and gives a fine grained crystalline structure
Blast furnace produces following by reduction of iron ore
Cast iron
Pig iron
Wrought iron
Malleable iron
Corrosion resistance of steel is increased by adding
Chromium and nickel
Nickel and molybdenum
Aluminium and zinc
Tungsten and sulphur