Pearlite consists of
13% carbon and 87% ferrite
13% cementite and 87% ferrite
13% ferrite and 87% cementite
6.67% carbon and 93.33% iron
Correct Answer :
B. 13% cementite and 87% ferrite
Related Questions
Muntz metal contains copper and zinc in the ratio of
50 : 50
40 : 60
60 : 40
20 : 80
The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
Chromium
Nickel
Vanadium
Cobalt
The most effective inhibitor of grain growth, when added in small quantities is
Carbon
Vanadium
Manganese
Cobalt
In induction hardening ________ is high.
Current
Voltage
Frequency
Temperature
Which of the following iron exist between 910°C and 1403°C?
α-iron
β-iron
γ-iron
δ-iron
Cemented carbide tools are not found to be suitable for cutting
Brass
Cast iron
Aluminium
Steel
1841 high speed steel contains
Vanadium 4%, chromium 18% and tungsten 1%
Vanadium 1%, chromium 4% and tungsten 18%
Vanadium 18%, chromium 1% and tungsten 4%
None of the above
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
A reversible change in the atomic structure of the steel with a corresponding change in the properties is known as
Allotropic change
Recrystallisation
Heat treatment
Precipitation
German silver contains
1% silver
2.5% silver
5% silver
10% silver
Chilled cast iron has
No graphite
A very high percentage of graphite
A low percentage of graphite
Graphite as its basic constituent of composition
The ratio of the volume occupied by the atoms to the total volume of the unit cell is called
Coordination number
Atomic packing factor
Space lattice
None of these
Admiralty gun metal contains
63 to 67% nickel and 30% copper
88% copper, 10% tin and rest zinc
Alloy of tin, lead and cadmium
Iron scrap and zinc
Which of the following metal shrinks most from molten state to solid state?
Cast iron
Cast steel
Brass
Admiralty metal
The elastic stress strain behaviour of rubber is
Linear
Nonlinear
Plastic
No fixed relationship
When medium carbon steel is heated to coarsening 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 purpose of heat treatment is to
Relieve the stresses set up in the material after hot or cold working
Modify the structure of the material
Change grain size
Any one of these
A material is known as allotropic or polymorphic if it
Has a fixed structure under all conditions
Exists in several crystal forms at different temperatures
Responds to heat treatment
Has its atoms distributed in a random pattern
The percentage of carbon in pig iron varies from
0.1 to 1.2%
1.5 to 2.5%
2.5 to 4%
4 to 4.5%
Steel made from phosphate iron is
Brittle
Hard
Ductile
Tough
The crystal structure of gamma iron is
Body centered cubic
Face centred cubic
Hexagonal close packed
Cubic structure
Super conduction by metals is observed in the temperature range of
Below 10°K
Above 100°K
Around 0°C
Around 100°C
Brass is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
An alloy of copper, tin and zinc is known as
Brass
Bronze
Gun metal
Muntz metal
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
Which of the following statements are true for annealing of steels?
Steels are heated to 500 to 700°C
Cooling is done slowly and steadily
Internal stresses are relieved
All of these
The coke in the charge of blast furnace
Controls the grade of pig iron
Acts as an iron bearing mineral
Supplies heat to reduce ore and melt the iron
Forms a slag by combining with impurities
Which of the following property is desirable for materials used in tools and machines?
Elasticity
Plasticity
Ductility
Malleability
The aluminium alloy made by melting aluminium with 2 to 10% magnesium and 1.75% copper is called
Duralumin
Y-alloy
Magnalium
Hindalium
Beryllium bronze has
High yield point
High fatigue limit
Both (A) and (B)
None of these