Chilled cast iron has
No graphite
A very high percentage of graphite
A low percentage of graphite
Graphite as its basic constituent of composition
Correct Answer :
A. No graphite
Related Questions
Cyaniding is the process of
Dipping steel in cyanide bath
Reacting steel surface with cyanide salts
Adding carbon and nitrogen by heat treatment of steel to increase its surface hardness
Obtaining cyanide salts
Addition of lead and bismuth to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
Sulphur in steel
Acts as deoxidiser
Reduces the grain size
Decreases tensile strength and hardness
Lowers the toughness and transverse ductility
Pipes for bicycle frames are made of
Cold rolled steel
Hot rolled steel
Forged steel
Cast steel
An important property of high silicon (12-18%) cast iron is the high
Hardness
Brittleness
Plasticity
Ductility
Manganese in steel increases its
Tensile strength
Hardness
Ductility
Fluidity
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 alloys does not have copper as one of the constituents?
Delta metal
Monel metal
Constantan
Nichrome
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 temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
770°C
910°C
1050°C
Below recrystallisation temperature
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 %
Eutectoid steel consists of
Wholly pearlite
Wholly austenite
Pearlite and ferrite
Pearlite and cementite
Surveying tapes are made of a material having low coefficient of expansion and enough strength. The alloy used is
Silver metal
Duralumin
Hastelloy
Invar
Points of arrest for iron correspond to
Stages at which allotropic forms change
Stages at which further heating does not increase temperature for some time
Stages at which properties do not change with increase in temperature
There is nothing like points of arrest
Inconel contains
65% nickel, 15% chromium and 20% iron
68% nickel, 29% copper and 3% other constituents
80% nickel and 20% chromium
80% nickel, 14% chromium and 6% iron
Nimonic contains __________ percentage of nickel as that of Inconel.
Same
Less
More
None of these
Mild steel belongs to the following category
Low carbon steel
Medium carbon steel
High carbon steel
Alloy steel
'Killed steels' are those steels
Which are destroyed by burning
Which after their destruction are recycled to produce fresh steel
Which are deoxidised in the ladle with silicon and aluminium
In which carbon is completely burnt
In low carbon steels, presence of small quantities of sulphur improves
Weldability
Formability
Machinability
Hardenability
The molecules in a solid move
In a random manner
In a haphazard way
In circular motion
Back and forth like tiny pendulums
Aluminium bronze contains
94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
10% aluminium and 90% copper
90% magnesium and 9% aluminium with some copper
The machinability of steel is increased by
Silicon and sulphur
Phosphorous, lead and sulphur
Sulphur, graphite and aluminium
Phosphorous and aluminium
According to Indian standard specifications, SG 400/15 means
Spheroidal graphite cast iron with B.H.N. 400 and minimum tensile strength 15 MPa
Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation
Spheroidal graphite cast iron with minimum compressive strength 400 MPa and 15 percent reduction in area
None of the above
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
Free cutting steels
Contain carbon in free from
Require minimum cutting force
Is used where rapid machining is the prime requirement
Can be cut freely
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
In malleable iron, carbon is present in the form of
Cementite
Free carbon
Flakes
Nodular aggregates of graphite
Which is false statement about normalizing? Normalizing is done to
Refine grain structure
Reduce segregation in casting
Improve mechanical properties
Induce stresses
Pearlite is a combination of
Ferrite and cementite
Cementite and gamma iron
Ferrite and austenite
Ferrite and iron graphite
Which of the following alloys does not contain tin?
White metal
Solder admiralty
Fusible metal
Phosphor bronze