The metal suitable for bearings subjected to heavy loads, is
Silicon bronze
White metal
Monel metal
Phosphor bronze
Correct Answer :
B. White metal
Related Questions
Sulphur in steel
Acts as deoxidiser
Reduces the grain size
Decreases tensile strength and hardness
Lowers the toughness and transverse ductility
Addition of copper to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
The basic constituents of Hastelloy are
Aluminium, copper etc.
Nickel, molybdenum etc.
Nickel, Copper, etc.
All of the above
Delta-iron occurs between the temperature ranges of
400°C to 600°C
600°C to 900°C
900°C to 1400°C
1400°C to 1530°C
Vanadium in high speed steels
Promotes decarburisation
Provides high hot hardness
Forms very hard carbides and thus increases wear resistance
Promotes retention of austenite
Alnico, an alloy used extensively for permanent magnets contains iron, nickel, aluminium and cobalt in the following ratio
50 : 20 : 20 : 10
40 : 30 : 20 : 10
50 : 20 : 10 : 20
30 : 20 : 30 : 20
Wrought iron is
Hard
High in strength
Highly resistant to corrosion
Heat treated to change its properties
Elinvar, an alloy used in precision instruments, hair springs for watches, etc. contains the following element as principal alloying element
Iron
Copper
Aluminium
Nickel
A steel containing 16 to 18% chromium and about 0.12% carbon is called
Ferritic stainless steel
Austenitic stainless steel
Martenistic stainless steel
Nickel steel
Shock resisting steels should have
Low wear resistance
Low hardness
Low tensile strength
Toughness
Drop forging dies contain carbon of the order of
0.1 to 0.2 %
0.25 to 0.5 %
0.6 to 0.7 %
0.7 to 0.9 %
In low carbon steels, presence of small quantities of sulphur improves
Weldability
Formability
Machinability
Hardenability
Smelting is the process of
Removing the impurities like clay, sand etc. from the iron ore by washing with water
Expelling moisture, carbon dioxide, sulphur and arsenic from the iron ore by heating in shallow kilns
Reducing the ore with carbon in the presence of a flux
All of the above
Large forgings, crank shafts, axles normally contain carbon up to
0.05 to 0.20 %
0.20 to 0.45 %
0.45 to 0.55 %
0.55 to 1.0 %
The brown smoke during the operation of a Bessemer converter indicates that the
Air is burning out silicon and manganese
Silicon and manganese has burnt and carbon has started oxidising
The converter must be titled to remove the contents of the converter
The brown smoke does not occur during the operation of a Bessemer converter
Hardness of upper bainite (acicular structure) is about
RC 65
RC 48
RC 57
RC 80
Age hardening is related to
Duralumin
Brass
Copper
Silver
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
When filing or machining cast iron makes our hands black, then it shows that ________ is present in cast iron.
Cementite
Free graphite
Both A and B
None of these
Which of the following alloys does not have copper as one of the constituents?
Delta metal
Monel metal
Constantan
Nichrome
Which of the following steel making process is being adopted at Rourkela (in India) Steel Plant?
Bessemer process
Open hearth process
Electric process
LD process
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
Tin base white metals are used where the bearings are subjected to
Large surface wear
Elevated temperatures
Light load and pressure
High pressure and load
The defect which takes place due to imperfect packing of atoms during crystallisation is known as
Line defect
Surface defect
Point defect
None of these
The ultimate tensile strength of low carbon steel by working at a high strain rate will
Decrease
Increase
Remain constant
First increase and then decrease
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
The hardness of steel depends upon the
Amount of cementite it contains
Amount of carbon it contains
Contents of alloying elements
Method of manufacture of steel
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
Blast furnace produces following by reduction of iron ore
Cast iron
Pig iron
Wrought iron
Malleable iron
Eutectoid steel consists of
Wholly pearlite
Wholly austenite
Pearlite and ferrite
Pearlite and cementite