Process of Austempering results in
Formation of bainite structure
Carburised structure
Martenistic structure
Lamellar layers of carbide distributed throughout the structure
Correct Answer :
A. Formation of bainite structure
Related Questions
Babbitt metal is a
Lead base alloy
Copper base alloy
Tin base alloy
Cadmium base alloy
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
Preheating is essential in welding
Cast iron
High speed steel
All nonferrous materials
All of the above
Which one of the following metals would work-harden more quickly than the others?
Copper
Brass
Lead
Silver
Chilled cast iron has
No graphite
A very high percentage of graphite
A low percentage of graphite
Graphite as its basic constituent of composition
Which of the following elements does not impart hardness to steel?
Copper
Chromium
Nickel
Silicon
Grey 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 is obtained by cooling rapidly. It is almost unmachinable
Is produced by annealing process. I is soft, tough and easily machined metal
Is produced by small additions o magnesium (or cerium) in the ladle Graphite is in nodular or spheroidal form and is well dispersed throughout the material
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
Addition of copper to aluminium results in
Improvement of casting characteristics
Improvement of corrosion resistance
One of the best known age and precipitation hardening systems
Improving machinability
Which of the following metal shrinks most from molten state to solid state?
Cast iron
Cast steel
Brass
Admiralty metal
Which of the following property is desirable for materials used in tools and machines?
Elasticity
Plasticity
Ductility
Malleability
Pick up wrong statement about wrought iron
It contains carbon of the order of 0 to 0.25%
It melts at 1535°C
It is very soft and ductile
It is made by adding suitable percentage of carbon to molten iron and subjecting the product to repeated hammering and rolling.
The carbon in the pig iron varies from
0.1 to 0.5 %
0.5 to 1 %
1 to 5 %
5 to 10 %
Which of the following element results in presence of free graphite in C.I.?
Carbon
Sulphur
Silicon
Manganese
Macrostructure of a material is, generally, examined by
Naked eye
Optical microscope
Metallurgical microscope
X-ray techniques
The maximum internal diameter of a blast furnace is about
3 m
6 m
9 m
12 m
Iron is
Paramagnetic
Ferromagnetic
Ferroelectric
Dielectric
Dislocations in materials refer to the following type of defect
Point defect
Line defect
Plane defect
Volumetric defect
Which of the following statement is true about brittle fracture?
High temperature and low strain rates favour brittle fracture
Many metals with hexagonal close packed (H.C.P) crystal structure commonly show brittle fracture
Brittle fracture is always preceded by noise
Cup and cone formation is characteristic for brittle materials
Brass is an alloy of
Copper and zinc
Copper and tin
Copper, tin and zinc
None of these
The steel widely used for motor car crankshafts is
Nickel steel
Chrome steel
Nickel-chrome steel
Silicon steel
The alloy used for making electrical resistances and heating elements is
Nichrome
Invar
Magnin
Elinvar
Slow plastic deformation of metals under a constant stress is known as
Creep
Fatigue
Endurance
Plastic deformation
In grey cast iron, carbon is present in the form of
Cementite
Free carbon
Flakes
Spheroids
Beryllium bronze has
High yield point
High fatigue limit
Both (A) and (B)
None of these
In mottled cast iron, carbon is available in
Free form
Combined form
Nodular form
Partly in free and partly in combined state
The electric process of steel making is especially adapted to
Alloy and carbon tool steel
Magnet steel
High speed tool steel
All of these
Steel containing ferrite and pearlite is
Hard
Soft
Tough
Hard and tough
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
Brass contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin