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
Correct Answer :
A. Air is burning out silicon and manganese
Related Questions
Free cutting steels
Contain carbon in free from
Require minimum cutting force
Is used where rapid machining is the prime requirement
Can be cut freely
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
In which of the following cases, consideration of creep is important
Flywheel of steam engine
Cast iron pipes
Cycle chains
Gas turbine blades
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
Duralumin contains
94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
92.5% aluminium, 40% copper, 2% nickel, and 1.5% Mg
10% aluminium and 90% copper
90% magnesium and 9% aluminium with some copper
Melting point of iron is
1539°C
1601°C
1489°C
1712°C
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 is false statement about annealing? Annealing is done to
Relieve stresses
Harden steel slightly
Improve machining characteristic
Soften material
Aluminium bronze contains
94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
10% aluminium and 90% copper
90% magnesium and 9% aluminium with some copper
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
Babbitt metal is a
Lead base alloy
Copper base alloy
Tin base alloy
Cadmium base alloy
Cyaniding is the process of
Dipping steel in cyanide bath
Reacting steel surface with cyanide salts
Adding carbon and nitrogen by heat treatment of steel to increase its surface hardness
Obtaining cyanide salts
Induction hardening is basically a
Carburising process
Surface hardening process
Core hardening process
None of these
An important property of high silicon (12-18%) cast iron is the high
Hardness
Brittleness
Plasticity
Ductility
Age-hardening is related with
Stainless steel
Gun metal
German silver
Duralumin
The percentage carbon content in wrought iron is about
0.02
0.1
02
0.4
The ability of a material to absorb energy in the plastic range is called
Resilience
Creep
Fatigue strength
Toughness
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
Cast iron is a
Ductile material
Malleable material
Brittle material
Tough material
'Killed steels' are those steels
Which are destroyed by burning
Which after their destruction are recycled to produce fresh steel
Which are deoxidised in the ladle with silicon and aluminium
In which carbon is completely burnt
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
Corrosion resistance of steel is increased by addition of
Chromium and nickel
Sulphur, phosphorus, lead
Vanadium, aluminium
Tungsten, molybdenum, vanadium, chromium
Compressive strength of grey cast iron in tonnes/cm is of the order of
35
57
710
1015
The aluminium alloy, mainly used, for anodized utensil manufacture, is
Duralumin
Y-alloy
Magnalium
Hindalium
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
The presence of sulphur in pig iron makes
It easily machinable
It brittle
It hard
The casting unsound
Free cutting steels
Are used where ease in machining is the criterion
Contain carbon in free form
Require least cutting force
Do not exist
Which one of the following metals would work-harden more quickly than the others?
Copper
Brass
Lead
Silver
A material is said to be allotropic, if it has
Fixed structure at all temperatures
Atoms distributed in random pattern
Different crystal structures at different temperatures
Any one of the above
When low carbon steel is heated up to upper 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