White cast iron
Contains 1.7 to 3.5% carbon in Free State and is obtained by the slow cooling of molten cast iron
Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Is produced by annealing process. It is soft, tough and easily machined metal
Is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
Correct Answer :
B. Is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable
Related Questions
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
Bronze is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
The lower critical point for all steels is
600°C
700°C
723°C
913°C
The carbon in the pig iron varies from
0.1 to 0.5 %
0.5 to 1 %
1 to 5 %
5 to 10 %
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
Which of the following display properties similar to that of steel?
Blackheart cast iron
White-heart cast iron
Both (A) and (B)
None of these
Structural steel contains following principal alloying elements
Nickel, chromium and manganese
Tungsten, molybdenum and phosphorous
Lead, tin, aluminium
Zinc, sulphur, and chromium
Muntz metal contains copper and zinc in the ratio of
50 : 50
40 : 60
60 : 40
20 : 80
Ductility of a material can be defined as
Ability to undergo large permanent deformations in compression
Ability to recover its original form
Ability to undergo large permanent deformations in tension
All of the above
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
Which of the following elements does not impart hardness to steel?
Copper
Chromium
Nickel
Silicon
Nodular iron has
High machinability
Low melting point
High tensile strength
All of the above
Smelting is the process of
Removing the impurities like clay, sand etc. from the iron ore by washing with water
Expelling moisture, carbon dioxide, sulphur and arsenic from the iron ore by heating in shallow kilns
Reducing the ore with carbon in the presence of a flux
All of the above
Following elements have face-centred cubic structure
Gamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt
Mg, Zn, Ti, Zr, Br, Cd
A iron (below 910°C and between 1400 to 1539°C), W
All of the above
Delta-iron occurs between the temperature ranges of
400°C to 600°C
600°C to 900°C
900°C to 1400°C
1400°C to 1530°C
Which of the following element results in presence of free graphite in C.I.?
Carbon
Sulphur
Silicon
Manganese
Thermoplastic materials are those materials which
Are formed into shape under heat and pressure and results in a permanently hard product
Do not become hard with the application of heat and pressure and no chemical change occurs
Are flexible and can withstand considerable wear under suitable conditions
Are used as a friction lining for clutches and brakes
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
Steel made from phosphate iron is
Brittle
Hard
Ductile
Tough
The main alloying elements high speed steel in order of increasing proportion are
Vanadium, chromium, tungsten
Tungsten, titanium, vanadium
Chromium, titanium, vanadium
Tungsten, chromium, titanium
Manganese in steel increases its
Tensile strength
Hardness
Ductility
Fluidity
Permalloy is a
Kind of stainless steel
None ferrous alloy
Polymer
Nickel and iron alloy having high permeability
Normalising of steel is done to
Refine the grain structure
Remove strains caused by cold working
Remove dislocations caused in the internal structure due to hot working
All of the above
An engineer's hammer is made of
Cast iron
Forged steel
Mild steel
High carbon steel
Which of the following iron exist between 910°C and 1403°C?
α-iron
β-iron
γ-iron
δ-iron
The presence of hydrogen in steel causes
Reduced neutron absorption cross-section
Improved Weldability
Embrittlement
Corrosion resistance
The metal suitable for bearings subjected to light loads, is
Silicon bronze
White metal
Monel metal
Phosphor bronze
Which of the following has highest specific strength of all structural materials?
Magnesium alloys
Titanium alloys
Chromium alloys
Magnetic steel alloys
The property of a material which enables it to retain the deformation permanently, is called
Brittleness
Ductility
Malleability
Plasticity
A cold chisel is made of
Mild steel
Cast iron
HSS
High carbon