According to Indian standard specifications, SG 400/15 means
Spheroidal graphite cast iron with B.H.N. 400 and minimum tensile strength 15 MPa
Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation
Spheroidal graphite cast iron with minimum compressive strength 400 MPa and 15 percent reduction in area
None of the above
Correct Answer :
B. Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation
Related Questions
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
Austenite is a combination of
Ferrite and cementite
Cementite and gamma iron
Ferrite and austenite
Ferrite and iron graphite
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
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
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.
Chromium when added to steel __________ the tensile strength.
Does not effect
Decreases
Increases
None of these
The maximum internal diameter of a blast furnace is about
3 m
6 m
9 m
12 m
Malleable 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 cerium) in the ladle. Graphite is in the nodular or spheroidal form and is well dispersed throughout the material
The correct sequence for descending order of machinability is
Grey cast iron, low carbon steel, wrought iron
Low carbon steel, grey cast iron, wrought iron
Wrought iron, low carbon steel, grey cast iron
Wrought iron, grey cast iron, low carbon steel
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
Cast iron has
High tensile strength
Its elastic limit close to the ultimate breaking strength
High ductility
All of the above
The property of a material due to which it breaks with little permanent distortion, is called
Brittleness
Ductility
Malleability
Plasticity
Dye penetrant method is generally used to locate
Core defects
Surface defects
Superficial defects
Temporary defects
Which of the following is an amorphous material?
Mica
Silver
Lead
Glass
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
The material in which the atoms are arranged chaotically, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these
In low carbon steels, ________ raises the yield point and improves the resistance to atmospheric corrosion.
Sulphur
Phosphorus
Manganese
Silicon
Chromium 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
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
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
Acidic 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
Basic constituents of Monel metal are
Nickel, copper
Nickel, molybdenum
Zinc, tin, lead
Nickel, lead and tin
Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
Sulphur
Phosphorus
Manganese
Silicon
Crystal structure of a material is, generally, examined by
Naked eye
Optical microscope
Metallurgical microscope
X-ray techniques
The temperature at which ferromagnetic alpha iron transforms to paramagnetic alpha iron is
770°C
910°C
1050°C
Below recrystallisation temperature
Compressive strength of grey cast iron in tonnes/cm is of the order of
35
57
710
1015
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
The alloying element which increases residual magnetism and coercive magnetic force in steel for magnets is
Chromium
Nickel
Vanadium
Cobalt
Isotropic materials are those which have the same
Elastic properties in all directions
Stresses induced in all directions
Thermal properties in all directions
Electric and magnetic properties in all directions
The temperature required for full annealing in hypereutectoid steel is
30°C to 50°C above upper critical temperature
30°C to 50°C below upper critical temperature
30°C to 50°C above lower critical temperature
30°C to 50°C below lower critical temperature