In high speed steels, manganese is used to tougher the metal and to increase its
Yield point
Critical temperature
Melting point
Hardness
Correct Answer :
B. Critical temperature
Related Questions
Brass is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
In which of the following cases, consideration of creep is important
Flywheel of steam engine
Cast iron pipes
Cycle chains
Gas turbine blades
Nodular iron has
High machinability
Low melting point
High tensile strength
All of the above
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
Amorphous material is one
In which atoms align themselves in a geometric pattern upon solidification
In which there is no definite atomic structure and atoms exist in a random pattern just as in a liquid
Which is not attacked by phosphorous
Which emits fumes on melting
Brass contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin
The heat treatment process used for softening hardened steel is
Carburising
Normalising
Annealing
Tempering
In mottled cast iron, carbon is available in
Free form
Combined form
Nodular form
Partly in free and partly in combined state
The transistor is made of
Silver
Gold
Copper
Germanium
The metal suitable for bearings subjected to light loads, is
Silicon bronze
White metal
Monel metal
Phosphor bronze
The alloying element which reduces the formation of iron sulphide in steel is
Chromium
Nickel
Vanadium
Manganese
Carbon in iron is an example of
Substitutional solution
Interstitial solid solution
Intermetallic compounds
All of the above
'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
Cast iron is characterised by minimum of following percentage of carbon
0.2 %
0.8 %
1.3 %
2 %
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
Nodular cast iron is produced by adding ________ to the molten cast iron.
Nickel
Chromium
Copper
Magnesium
An important property of high silicon (12-18%) cast iron is the high
Hardness
Brittleness
Plasticity
Ductility
Coarse grained steel
Is less tough and has a greater tendency to distort during heat treatment
Is more ductile and has a less tendency to distort during heat treatment
Is less tough and has a less tendency to distort during heat treatment
Is more ductile and has a greater tendency to distort during heat treatment
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
Basic constituents of Monel metal are
Nickel, copper
Nickel, molybdenum
Zinc, tin, lead
Nickel, lead and tin
The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
770°C
910°C
1050°C
Below recrystallisation temperature
Iron ore is, usually, found in the form of
Oxides
Carbonates
Sulphides
All of these
The presence of sulphur in pig iron makes
It easily machinable
It brittle
It hard
The casting unsound
Free cutting steels
Are used where ease in machining is the criterion
Contain carbon in free form
Require least cutting force
Do not exist
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
The machinability of aluminium increases when __________ is added to aluminium.
Copper
Magnesium
Silicon
Lead and bismuth
Sulphur in pig iron tends to make it
Hard
Soft
Ductile
Tough
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
Increase
Decrease
Remain same
First increase and then decrease
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
Aluminium bronze contains aluminium and copper in the ratio of
50 : 50
40 : 60
60 : 40
10 : 90