In which of the following cases, consideration of creep is important
Flywheel of steam engine
Cast iron pipes
Cycle chains
Gas turbine blades
Correct Answer :
D. Gas turbine blades
Related Questions
Beryllium bronze has
High yield point
High fatigue limit
Both (A) and (B)
None of these
Which of the following material has nearly zero coefficient of expansion?
Stainless steel
High speed steel
Invar
Heat resisting steel
The property of a material essential for spring materials is
Stiffness
Ductility
Resilience
Plasticity
Super conduction by metals is observed in the temperature range of
Below 10°K
Above 100°K
Around 0°C
Around 100°C
Which of the following is not the correct method of increasing fatigue limit?
Shot peening
Nitriding of surface
Cold working
Surface decarburisation
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
A material is known as allotropic or polymorphic if it
Has a fixed structure under all conditions
Exists in several crystal forms at different temperatures
Responds to heat treatment
Has its atoms distributed in a random pattern
The type of space lattice found in alpha-iron is
Face centred cubic space lattice
Body centred cubic space lattice
Close packed hexagonal space lattice
None of these
The alloy, mainly used for corrosion resistance in stainless steels is
Silicon
Manganese
Carbon
Chromium
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
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
Y-alloy 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
Which of the following property is desirable in parts subjected to shock and impact loads?
Strength
Stiffness
Brittleness
Toughness
The carbon in the pig iron varies from
0.1 to 0.5 %
0.5 to 1 %
1 to 5 %
5 to 10 %
A reversible change in the atomic structure of steel with corresponding change in the properties is known as
Molecular change
Physical change
Allotropic change
Solidus change
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
The property of a material due to which it breaks with little permanent distortion, is called
Brittleness
Ductility
Malleability
Plasticity
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
A small percentage of boron is added to steel in order to
Increase hardenability
Reduce machinability
Increase wear resistance
Increase endurance strength
Maximum percentage of carbon in ferrite is
0.025 %
0.06 %
0.1 %
0.25 %
Induction hardening is the process of
Hardening surface of work-piece to obtain hard and wear resistant surface
Heating and cooling rapidly
Increasing hardness throughout
Inducing hardness by continuous process
The temperature required for full annealing in hypereutectoid steel is
30°C to 50°C above upper critical temperature
30°C to 50°C below upper critical temperature
30°C to 50°C above lower critical temperature
30°C to 50°C below lower critical temperature
Which one of the following metals would work-harden more quickly than the others?
Copper
Brass
Lead
Silver
The hardness and tensile strength in austenitic stainless steel can be increased by
Hardening and cold working
Normalising
Martempering
Full annealing
Gun metal contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 78% copper and rest tin
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
The material in which the atoms are arranged regularly in some directions but not in others, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these
Monel metal is an alloy of
Nickel and copper
Nickel and chromium
Nickel, Chromium and iron
Copper and chromium
When low carbon steel is heated up to lower critical temperature
There is no change in grain size
The average grain size is a minimum
The grain size increases very rapidly
The grain size first increases and then decreases very rapidly
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