Materials after cold working are subjected to following process to relieve stresses
Hot working
Tempering
Normalising
Annealing
Correct Answer :
D. Annealing
Related Questions
The compressive strength of cast iron is ________ that of its tensile strength.
Equal to
Less than
More than
None of these
Blast furnace produces following by reduction of iron ore
Cast iron
Pig iron
Wrought iron
Malleable iron
A small percentage of boron is added to steel in order to
Increase hardenability
Reduce machinability
Increase wear resistance
Increase endurance strength
Nodular iron has
High machinability
Low melting point
High tensile strength
All of the above
The toughness of a material __________ when it is heated.
Remain same
Decreases
Increases
None of these
Gamma iron exits at following temperature
Room temperature
Near melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
The strength is the ability of a material to resist
Deformation under stress
Externally applied forces with breakdown or yielding
Fracture due to high impact loads
None of these
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
The crystal structure of gamma iron is
Body centered cubic
Face centred cubic
Hexagonal close packed
Cubic structure
Maximum percentage of carbon in ferrite is
0.025 %
0.06 %
0.1 %
0.25 %
The property of a material due to which it breaks with little permanent distortion, is called
Brittleness
Ductility
Malleability
Plasticity
The percentage carbon content in wrought iron is about
0.02
0.1
02
0.4
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
Pipes for bicycle frames are made of
Cold rolled steel
Hot rolled steel
Forged steel
Cast steel
Machining properties of steel are improved by adding
Sulphur, lead, phosphorous
Silicon, aluminium, titanium
Vanadium, aluminium
Chromium, nickel
Isotropic materials are those which have the same
Elastic properties in all directions
Stresses induced in all directions
Thermal properties in all directions
Electric and magnetic properties in all directions
The steel widely used for motor car crankshafts is
Nickel steel
Chrome steel
Nickel-chrome steel
Silicon steel
The crystal structure of brass is
F.C.C.
B.C.C.
H.C.P.
Orthorhombic crystalline structure
In low carbon steels, ________ raises the yield point and improves the resistance to atmospheric corrosion.
Sulphur
Phosphorus
Manganese
Silicon
A cold chisel is made of
Mild steel
Cast iron
HSS
High carbon
In high speed steels, manganese is used to tougher the metal and to increase its
Yield point
Critical temperature
Melting point
Hardness
Preheating is essential in welding
Cast iron
High speed steel
All nonferrous materials
All of the above
Materials after cold working are subjected to following process to relieve stresses
Hot working
Tempering
Normalising
Annealing
Which of the following material has maximum ductility?
Mild steel
Copper
Nickel
Aluminium
The hardness of steel increases if it contains
Austenite
Martensite
Pearlite
Cementite
The percentage of carbon in cast iron varies from
0.1 to 0.5
0.5 to 1
1 to 1.7
1.7 to 4.5
If a refractory contains high content of silicon, it means refractory is
Acidic
Basic
Neutral
Brittle
Dislocations in materials refer to the following type of defect
Point defect
Line defect
Plane defect
Volumetric defect
Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio
50 : 50
30 : 70
70 : 30
40 : 60
The coordination number of a face centred cubic space lattice is
Six
Twelve
Eighteen
Twenty