In full annealing, the hypo eutectoid steel is heated from 30°C to 50°C above the upper critical temperature and then cooled
In still air
Slowly in the furnace
Suddenly in a suitable cooling medium
Any one of these
Correct Answer :
B. Slowly in the furnace
Related Questions
The presence of hydrogen in steel causes
Reduced neutron absorption cross-section
Improved Weldability
Embrittlement
Corrosion resistance
The strength is the ability of a material to resist
Deformation under stress
Externally applied forces with breakdown or yielding
Fracture due to high impact loads
None of these
The bond formed by transferring electrons from one atom to another is called
Ionic bond
Covalent bond
Metallic bond
None of these
The ability of a material to resist fracture due to high impact loads, is called
Strength
Stiffness
Toughness
Brittleness
The alloying element which can replace tungsten in high speed steels is
Nickel
Vanadium
Cobalt
Molybdenum
The stiffness is the ability of a material to resist
Deformation under stress
Fracture due to high impact loads
Externally applied forces with breakdown or yielding
None of the above
Which of the following element results in presence of free graphite in C.I.?
Carbon
Sulphur
Silicon
Manganese
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
Addition of silicon to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
Induction hardening is the process of
Hardening surface of work-piece to obtain hard and wear resistant surface
Heating and cooling rapidly
Increasing hardness throughout
Inducing hardness by continuous process
The alloy, mainly used for corrosion resistance in stainless steels is
Silicon
Manganese
Carbon
Chromium
Which of the following metal shrinks most from molten state to solid state?
Cast iron
Cast steel
Brass
Admiralty metal
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
Dow metal contains
94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
92.5% aluminium and, 4% copper, 2% nickel and 1.5% Mg
90% aluminium and 90% copper
90% magnesium and 9% aluminium with some copper
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
Foundry crucible is made of
Mild steel
German silver
Lead
Graphite
The property of a material essential for spring materials is
Stiffness
Ductility
Resilience
Plasticity
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
The tensile strength of wrought iron is maximum
Along the lines of slag distribution
Perpendicular to lines of slag distribution
Uniform in all directions
None of the above
Sulphur in pig iron tends to make it
Hard
Soft
Ductile
Tough
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
In a hardening process, the hypo-eutectoid steel is
Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
Heated below or closes to the lower critical temperature and then cooled slowly
Basic constituents of Monel metal are
Nickel, copper
Nickel, molybdenum
Zinc, tin, lead
Nickel, lead and tin
'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
Depth of hardness of steel is increased by addition of
Nickel
Chromium
Tungsten
Vanadium
Pick up the wrong statement
Aluminium in steel results in excessive grain growth
Manganese in steel induces hardness
Nickel and chromium in steel helps in raising the elastic limit and improve the resilience and ductility
Tungsten in steels improves magnetic properties and hardenability
Cast iron is manufactured in
Blast furnace
Cupola
Open hearth furnace
Bessemer converter
In compression, a prism of brittle material will break
By forming a bulge
By shearing along oblique plane
In direction perpendicular to application of load
By crushing into thousands of pieces
Sulphur in steel
Acts as deoxidiser
Reduces the grain size
Decreases tensile strength and hardness
Lowers the toughness and transverse ductility
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
Increase
Decrease
Remain same
First increase and then decrease