The following element can't impart high strength at elevated temperature
Manganese
Magnesium
Nickel
Silicon
Correct Answer :
B. Magnesium
Related Questions
A reversible change in the atomic structure of steel with corresponding change in the properties is known as
Molecular change
Physical change
Allotropic change
Solidus change
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
The following types of materials are usually the most ductile
Face centred cubic lattice
Body centred cubic lattice
Hexagonal close packed lattice
All of the above
Coarse grained steel
Is less tough and has a greater tendency to distort during heat treatment
Is more ductile and has a less tendency to distort during heat treatment
Is less tough and has a less tendency to distort during heat treatment
Is more ductile and has a greater tendency to distort during heat treatment
Which is false statement about properties of aluminium?
Modulus of elasticity is fairly low
Wear resistance is very good
Fatigue strength is not high
Creep strength limits its use to fairly low temperatures
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
Nickel in steel
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
Improves cutting ability and reduces hardenability
Gives ductility, toughness, tensile strength and anticorrosion properties
Blast furnace is used to produce
Pig iron
Cast iron
Wrought iron
Steel
Silicon when added to copper improves
Machinability
Hardness
Hardness and strength
Strength and ductility
The basic constituents of Hastelloy are
Aluminium, copper etc.
Nickel, molybdenum etc.
Nickel, Copper, etc.
All of the above
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
Which of the following iron exist between 910°C and 1403°C?
α-iron
β-iron
γ-iron
δ-iron
An example of amorphous material is
Zinc
Lead
Silver
Glass
Eutectoid steel contains following percentage of carbon
0.02 %
0.3 %
0.63 %
0.8 %
Steel with ________ carbon is known as hypo-eutectoid steel.
0.8 %
Below 0.8 %
Above 0.8 %
None of these
The property of a material essential for spring materials is
Stiffness
Ductility
Resilience
Plasticity
The coordination number of a face centred cubic space lattice is
Six
Twelve
Eighteen
Twenty
German silver contains
1% silver
2.5% silver
5% silver
10% silver
Which of the following metal shrinks most from molten state to solid state?
Cast iron
Cast steel
Brass
Admiralty metal
Maximum percentage of carbon in austenite is
0.025 %
0.26 %
0.8 %
1.7 %
The charge is fed into the blast furnace through the
Stack
Throat
Bosh
Tyres
The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
Chromium
Nickel
Vanadium
Cobalt
Steel containing ferrite and pearlite is
Hard
Soft
Tough
Hard and tough
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
Basic constituents of Monel metal are
Nickel, copper
Nickel, molybdenum
Zinc, tin, lead
Nickel, lead and tin
In mottled cast iron, carbon is available in
Free form
Combined form
Nodular form
Partly in free and partly in combined state
Addition of manganese to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
A material is known as allotropic or polymorphic if it
Has a fixed structure under all conditions
Exists in several crystal forms at different temperatures
Responds to heat treatment
Has its atoms distributed in a random pattern
Solder is an alloy consisting of
Tin, antimony, copper
Tin and copper
Tin and lead
Lead and zinc