When medium carbon steel is heated to coarsening 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
Correct Answer :
C. The grain size increases very rapidly
Related Questions
Body centered cubic space lattice is found in
Zinc, magnesium, cobalt, cadmium, antimony and bismuth
Gamma iron, aluminium, copper, lead, silver and nickel
Alpha iron, tungsten, chromium and molybdenum
None of the above
Beryllium bronze has
High yield point
High fatigue limit
Both (A) and (B)
None of these
Babbitt metal is a
Lead base alloy
Copper base alloy
Tin base alloy
Cadmium base alloy
An important property of high silicon (12-18%) cast iron is the high
Hardness
Brittleness
Plasticity
Ductility
Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
Sulphur
Phosphorus
Manganese
Silicon
Dislocations in materials refer to the following type of defect
Point defect
Line defect
Plane defect
Volumetric defect
Machining properties of steel are improved by adding
Sulphur, lead, phosphorous
Silicon, aluminium, titanium
Vanadium, aluminium
Chromium, nickel
Steel containing ferrite and pearlite is
Hard
Soft
Tough
Hard and tough
Ferromagnetic alpha iron exists in temperature range of
Below 723°C
770 to 910°C
910 to 1440°C
1400 to 1539°C
The blade of a power saw is made of
Boron steel
High speed steel
Stainless steel
Malleable cast iron
Age hardening is related to
Duralumin
Brass
Copper
Silver
Monel metal contains
63 to 67% nickel and 30% copper
88% copper and 10% tin and rest zinc
Alloy of tin, lead and cadmium
Malleable iron and zinc
Structural steel contains following principal alloying elements
Nickel, chromium and manganese
Tungsten, molybdenum and phosphorous
Lead, tin, aluminium
Zinc, sulphur, and chromium
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
Corundum contains more than 95%
Steel
Al2O3
SiO2
MgO
Process of Austempering results in
Formation of bainite structure
Carburised structure
Martenistic structure
Lamellar layers of carbide distributed throughout the structure
Beryllium bronze contains
60% copper and 40% beryllium
80% copper and 20% beryllium
97.75% copper and 2.25% beryllium
99% copper and 1% beryllium
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
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
Which of the following material has maximum ductility?
Mild steel
Copper
Nickel
Aluminium
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
The correct composition of Babbitt metal is
87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
87% Sn, 4% Cu, 8% Sb, 1% Al
82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg
Muntz metal contains copper and zinc in the ratio of
50 : 50
40 : 60
60 : 40
20 : 80
Cast iron has
High tensile strength
Its elastic limit close to the ultimate breaking strength
High ductility
All of the above
German silver contains
1% silver
2.5% silver
5% silver
10% silver
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
Dye penetrant method is generally used to locate
Core defects
Surface defects
Superficial defects
Temporary defects
An important property of malleable cast iron in comparison to grey cast iron is the high
Compressive strength
Ductility
Carbon content
Hardness
The percentage of carbon in pig iron varies from
0.1 to 1.2%
1.5 to 2.5%
2.5 to 4%
4 to 4.5%
Surveying tapes are made of a material having low coefficient of expansion and enough strength. The alloy used is
Silver metal
Duralumin
Hastelloy
Invar