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
Correct Answer :
B. Hypoeutectic cast irons
Related Questions
Paramagnetic alpha iron changes to gamma iron at
770°C
910°C
1440°C
1539°C
The correct sequence for descending order of machinability is
Grey cast iron, low carbon steel, wrought iron
Low carbon steel, grey cast iron, wrought iron
Wrought iron, low carbon steel, grey cast iron
Wrought iron, grey cast iron, low carbon steel
Which one of the following metals would work-harden more quickly than the others?
Copper
Brass
Lead
Silver
Chromium 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
Nodular iron has
High machinability
Low melting point
High tensile strength
All of the above
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
Connecting rod is, usually, made from
Low carbon steel
High carbon steel
Medium carbon steel
High speed steel
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
Blast furnace produces following by reduction of iron ore
Cast iron
Pig iron
Wrought iron
Malleable iron
Hardness of martensite is about
RC 65
RC 48
RC 57
RC 80
Cobalt in steel
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improve corrosion and heat resistant proper ties
Improves cutting ability and reduce hardenability
Gives ductility, toughness, tensile strength and anti corrosion property
The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
Chromium
Nickel
Vanadium
Cobalt
Neutral solution is one which has pH value
Greater than 7
Less than 7
Equal to 7
pH value has nothing to do with neutral solution
An engineer's hammer is made of
Cast iron
Forged steel
Mild steel
High carbon steel
The percentage carbon content in wrought iron is about
0.02
0.1
02
0.4
In spheroidising process, the steel is
Heated below the lower critical temperature and then cooled slowly
Heated up to the lower critical temperature and then cooled in still air
Heated slightly above the lower critical temperature and then cooled slowly to a temperature of 600°C
None of the above
The blade of a power saw is made of
Boron steel
High speed steel
Stainless steel
Malleable cast iron
The percentage of carbon in cast iron varies from
0.1 to 0.5
0.5 to 1
1 to 1.7
1.7 to 4.5
The percentage of carbon in low carbon steel is
0.05 %
0.15 %
0.3 %
0.5 %
Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
Sulphur
Phosphorus
Manganese
Silicon
Cupola produces following material
Cast iron
Pig iron
Wrought iron
Malleable iron
The hardness of steel primarily depends on
Percentage of carbon
Percentage of alloying elements
Heat treatment employed
Shape of carbides and their distribution in iron
The lower critical point for all steels is
600°C
700°C
723°C
913°C
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 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%
Eutectoid steel consists of
Wholly pearlite
Wholly austenite
Pearlite and ferrite
Pearlite and cementite
Pick up the wrong statement Nickel and chromium in steel help in
Providing corrosion resistance
Improving machining properties
Providing high strength at elevated temperatures
Raising the elastic limit
Which is false statement about annealing? Annealing is done to
Relieve stresses
Harden steel slightly
Improve machining characteristic
Soften material
Which is false statement about normalizing? Normalizing is done to
Refine grain structure
Reduce segregation in casting
Improve mechanical properties
Induce stresses
Tungsten when added to steel ________ the critical temperature.
Does not effect
Lowers
Raises
None of these