Delta iron occurs at temperature of
Room temperature
Above melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
Correct Answer :
C. Between 1400°C and 1539°C
Related Questions
Slow plastic deformation of metals under a constant stress is known as
Creep
Fatigue
Endurance
Plastic deformation
Taps dies and drills contain carbon
Below 0.5 %
Below 1 %
Above 1 %
Above 2.2 %
Stress relaxation is the phenomenon
In which parts are not loaded
In which stress remains constant on increasing load
In which deformation tends to loosen the joint and produces a stress reduced
Stress reduces on increasing load
White metal contains
63 to 67% nickel and 30% copper
88% copper and 10% tin and rest zinc
Alloy of tin, lead and cadmium
Silver and chromium
Basic solution is one which has pH value
Greater than 7
Equal to 7
Less than 7
pH value has nothing to do with basic solution
Induction hardening is basically a
Carburising process
Surface hardening process
Core hardening process
None of these
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
Quenching is not necessary when hardening is done by
Case hardening
Flame hardening
Nitriding
Any one of these
Brass is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
Sulphur in steel
Acts as deoxidiser
Reduces the grain size
Decreases tensile strength and hardness
Lowers the toughness and transverse ductility
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
If a refractory contains high content of silicon, it means refractory is
Acidic
Basic
Neutral
Brittle
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 represents the allotropic forms of iron?
Alpha iron, beta iron and gamma iron
Alpha iron and beta iron
Body centred cubic iron and face centred cubic iron
Alpha iron, gamma from and delta iron
Which of the following impurity in cast iron promotes graphite nodule formation and increases the fluidity of the molten metal?
Silicon
Sulphur
Manganese
Phosphorus
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
Carbon in iron is an example of
Substitutional solution
Interstitial solid solution
Intermetallic compounds
All of the above
Which of the following iron exist between 910°C and 1403°C?
α-iron
β-iron
γ-iron
δ-iron
Malleable cast iron is produced
By adding magnesium to molten cast iron
By quick cooling of molten cast iron
From white cast iron by annealing process
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
1841 high speed steel contains
Vanadium 4%, chromium 18% and tungsten 1%
Vanadium 1%, chromium 4% and tungsten 18%
Vanadium 18%, chromium 1% and tungsten 4%
None of the above
Aluminium bronze contains aluminium and copper in the ratio of
50 : 50
40 : 60
60 : 40
10 : 90
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
Shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Sulphur, lead and phosphorus
Which of the following alloys does not have copper as one of the constituents?
Delta metal
Monel metal
Constantan
Nichrome
Which of the following property is desirable for materials used in tools and machines?
Elasticity
Plasticity
Ductility
Malleability
In process annealing, the hypo eutectoid steel is
Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
Heated below or closes to the lower critical temperature and then cooled slowly
Nimonic contains __________ percentage of nickel as that of Inconel.
Same
Less
More
None of these
Steel with ________ carbon is known as hypo-eutectoid steel.
0.8 %
Below 0.8 %
Above 0.8 %
None of these
Tungsten when added to steel ________ the critical temperature.
Does not effect
Lowers
Raises
None of these