Ductile 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 :
D. 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
Related Questions
Which of the following statement is wrong?
Steel with 0.8% carbon is wholly pearlite
The amount of cementite increases with the increase in percentage of carbon in iron
A mechanical mixture of 87% cementite and 13% ferrite is called pearlite
The cementite is identified as round particles in the structure
In basic Bessemer process, the furnace is lined with
Silica bricks
A mixture of tar and burnt dolomite bricks
Both (A) and (B)
None of these
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
German silver contains
1% silver
2% silver
5% silver
No silver
Sulphur in cast iron
Makes the iron soft and easily machinable
Increases hardness and brittleness
Make the iron white and hard
Aids fusibility and fluidity
Cemented carbide tools are not found to be suitable for cutting
Brass
Cast iron
Aluminium
Steel
Admiralty gun metal contains
63 to 67% nickel and 30% copper
88% copper, 10% tin and rest zinc
Alloy of tin, lead and cadmium
Iron scrap and zinc
Cast iron is characterised by minimum of following percentage of carbon
0.2 %
0.8 %
1.3 %
2 %
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 electric process of steel making is especially adapted to
Alloy and carbon tool steel
Magnet steel
High speed tool steel
All of these
The transistor is made of
Silver
Gold
Copper
Germanium
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
Ductile 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
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
When a steel containing ________ 0.8% carbon is cooled slowly below the lower critical point, it consists of ferrite and pearlite.
Equal to
Less than
More than
None of these
In grey cast iron, carbon is present in the form of
Cementite
Free carbon
Flakes
Spheroids
Cobalt in steel
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improve corrosion and heat resistant proper ties
Improves cutting ability and reduce hardenability
Gives ductility, toughness, tensile strength and anti corrosion property
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
The crystal of alpha iron is
Body centered cubic
Face centered cubic
Hexagonal close packed
Cubic structure
Corrosion resistance of steel is increased by adding
Chromium and nickel
Nickel and molybdenum
Aluminium and zinc
Tungsten and sulphur
The hardness of steel primarily depends on
Percentage of carbon
Percentage of alloying elements
Heat treatment employed
Shape of carbides and their distribution in iron
Grey cast iron has
Carbon in the form of free graphite
High tensile strength
Low compressive strength
All 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
Eutectoid reaction occurs at
600°C
723°C
1147°C
1493°C
Wrought iron
Is a ductile material
Can be easily forged or welded
Cannot stand sudden and excessive shocks
All of these
Admiralty brass used for steam condenser tubes contains copper and zinc in the following ratio
50 : 50
30 : 70
70 : 30
40 : 60
The alloy used for making electrical resistances and heating elements is
Nichrome
Invar
Magnin
Elinvar
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
Slow plastic deformation of metals under a constant stress is known as
Creep
Fatigue
Endurance
Plastic deformation
In the lower part of the blast furnace (zone of fusion), the temperature is
400° to 700°C
800°C to 1000°C
1200°C to 1300°C
1500°C to 1700°C