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
Correct Answer :
C. Is used where rapid machining is the prime requirement
Related Questions
When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces
White cast iron
Nodular cast iron
Malleable cast iron
Alloy cast iron
The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
770°C
910°C
1050°C
Below recrystallisation temperature
Stress relaxation is the phenomenon
In which parts are not loaded
In which stress remains constant on increasing load
In which deformation tends to loosen the joint and produces a stress reduced
Stress reduces on increasing load
An alloy steel which is work hardenable and which is used to make the blades of bulldozers, bucket wheel excavators and other earth moving equipment contain iron, carbon and
Chromium
Silicon
Manganese
Magnesium
Gamma-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
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
In low carbon steels, ________ raises the yield point and improves the resistance to atmospheric corrosion.
Sulphur
Phosphorus
Manganese
Silicon
The alloying element which can replace tungsten in high speed steels is
Nickel
Vanadium
Cobalt
Molybdenum
The crystal structure of gamma iron is
Body centered cubic
Face centred cubic
Hexagonal close packed
Cubic structure
Which is false statement about tempering? Tempering is done to
Improve machinability
Improve ductility
Improve toughness
Release stresses
Chilled cast iron has
No graphite
A very high percentage of graphite
A low percentage of graphite
Graphite as its basic constituent of composition
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
Nimonic contains __________ percentage of nickel as that of Inconel.
Same
Less
More
None of these
The hardness is the property of a material due to which it
Can be drawn into wires
Breaks with little permanent distortion
Can cut another metal
Can be rolled or hammered into thin sheets
Balls for ball bearings are made of
Cast iron
Mild steel
Stainless steel
Carbonchrome steel
When low carbon steel is heated up to lower 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
Which of the following property is desirable in parts subjected to shock and impact loads?
Strength
Stiffness
Brittleness
Toughness
The alloy used for making electrical resistances and heating elements is
Nichrome
Invar
Magnin
Elinvar
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
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
Depth of hardness of steel is increased by addition of
Nickel
Chromium
Tungsten
Vanadium
Neutral solution is one which has pH value
Greater than 7
Less than 7
Equal to 7
pH value has nothing to do with neutral solution
When the steel is normalised, its
Yield point increases
Ductility decreases
Ultimate tensile strength increases
All of these
Which of the following is not the correct method of increasing fatigue limit?
Shot peening
Nitriding of surface
Cold working
Surface decarburisation
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
Brass (alloy of copper and zinc) is an example of
Substitutional solid solution
Interstitial solid solution
Intermetallic compounds
All of the above
Hardness of martensite is about
RC 65
RC 48
RC 57
RC 80
In induction hardening ________ is high.
Current
Voltage
Frequency
Temperature
Tensile strength of steel can be safely increased by
Adding carbon up to 2.8%
Adding carbon up to 6.3%
Adding carbon up to 0.83%
Adding small quantities of copper