Cast iron has
High tensile strength
Its elastic limit close to the ultimate breaking strength
High ductility
All of the above
Correct Answer :
B. Its elastic limit close to the ultimate breaking strength
Related Questions
Quenching is not necessary when hardening is done by
Case hardening
Flame hardening
Nitriding
Any one of these
Which of the following display properties similar to that of steel?
Blackheart cast iron
White-heart cast iron
Both (A) and (B)
None of these
Which of the following is used for bearing liner?
Gun metal
Bronze
Bell metal
Babbitt metal
There are fourteen atoms in a unit cell of
Body centred cubic space lattice
Face centred cubic space lattice
Close packed hexagonal space lattice
None of these
Taps dies and drills contain carbon
Below 0.5 %
Below 1 %
Above 1 %
Above 2.2 %
Steel contains
80% or more iron
50% or more iron
Alloying elements like chromium, tungsten nickel and copper
Elements like phosphorus, sulphur and silicon in varying quantities
The material in which the atoms are arranged chaotically, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these
The addition of which of the following improves machining of copper?
Sulphur
Vanadium
Tin
Zinc
Which of the following is not the correct method of increasing fatigue limit?
Shot peening
Nitriding of surface
Cold working
Surface decarburisation
Carbon steel is
Made by adding carbon in steel
Refined from cast iron
An alloy of iron and carbon with varying quantities of phosphorus and sulphur
Extensively used for making cutting tools
Hardness of steel depends on
Amount of carbon it contains
The shape and distribution of the carbides in iron
Method of fabrication
Contents of alloying elements
Cartridge brass can be
Cold rolled into sheets
Drawn into wires
Formed into tube
Any one of these
The main alloying elements high speed steel in order of increasing proportion are
Vanadium, chromium, tungsten
Tungsten, titanium, vanadium
Chromium, titanium, vanadium
Tungsten, chromium, titanium
Preheating is essential in welding
Cast iron
High speed steel
All nonferrous materials
All of the above
The loss of strength in compression with simultaneous gain in strength in tension due to overloading is known as
Hysteresis
Creep
Visco elasticity
Boeschinger effect
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
The blade of a power saw is made of
Boron steel
High speed steel
Stainless steel
Malleable cast iron
Which of the following is the binding material in cemented carbides?
Cobalt
Nickel
Vanadium
Iron
Sulphur in cast iron
Makes the iron soft and easily machinable
Increases hardness and brittleness
Make the iron white and hard
Aids fusibility and fluidity
A small percentage of boron is added to steel in order to
Increase hardenability
Reduce machinability
Increase wear resistance
Increase endurance strength
The hardness of steel increases if it contains
Austenite
Martensite
Pearlite
Cementite
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
The ability of a material to resist softening at high temperature is known as
Creep
Hot tempering
Hot hardness
Fatigue
Hematite iron ore contains iron about
30 %
45 %
55 %
70 %
Babbitt metal is a
Lead base alloy
Copper base alloy
Tin base alloy
Cadmium base alloy
Duralumin contains
3.5 to 4.5% copper, 0.4 to 0.7% magnesium, 0.4 to 0.7% manganese and rest aluminium
3.5 to 4.5% copper, 1.2 to 1.7% manganese, 1.8 to 2.3% nickel, 0.6% each of silicon, magnesium and iron, and rest aluminium
4 to 4.5% magnesium, 3 to 4% copper and rest aluminium
5 to 6% tin, 2 to 3% copper and rest aluminium
Addition of manganese to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
German silver is an alloy of
Silver and some impurities
Refined silver
Nickel, Copper and zinc
Nickel and copper
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 percentage carbon content in wrought iron is about
0.02
0.1
02
0.4