Foundry crucible is made of
Mild steel
German silver
Lead
Graphite
Correct Answer :
D. Graphite
Related Questions
Ductile 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 creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the material
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
The unique property of cast iron is its high
Malleability
Ductility
Surface finish
Damping characteristics
Which of the following pipes is least corrosion resistant?
Brass
Mild steel
Cast iron
Wrought iron
In mottled cast iron, carbon is available in
Free form
Combined form
Nodular form
Partly in free and partly in combined state
Pig iron is the name given to
Raw material for blast furnace
Product of blast furnace made by reduction of iron ore
Iron containing huge quantities of carbon
Iron in molten form in the ladles
German silver contains
1% silver
2.5% silver
5% silver
10% 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 alloys does not have copper as one of the constituents?
Delta metal
Monel metal
Constantan
Nichrome
When the steel is normalised, its
Yield point increases
Ductility decreases
Ultimate tensile strength increases
All of these
The loss of strength in compression with simultaneous gain in strength in tension due to overloading is known as
Hysteresis
Creep
Visco elasticity
Boeschinger effect
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
Which of the following statement is wrong?
Steel with 0.8% carbon is wholly pearlite
The amount of cementite increases with the increase in percentage of carbon in iron
A mechanical mixture of 87% cementite and 13% ferrite is called pearlite
The cementite is identified as round particles in the structure
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
Which of the following elements does not impart hardness to steel?
Copper
Chromium
Nickel
Silicon
Ferromagnetic alpha iron exists in temperature range of
Below 723°C
770 to 910°C
910 to 1440°C
1400 to 1539°C
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
There are fourteen atoms in a unit cell of
Body centred cubic space lattice
Face centred cubic space lattice
Close packed hexagonal space lattice
None of these
Which of the following statements are true for annealing of steels?
Steels are heated to 500 to 700°C
Cooling is done slowly and steadily
Internal stresses are relieved
All of these
In process annealing, 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
Following elements have face-centred cubic structure
Gamma iron (910° to 1400°C), Cu, Ag, Au, Al, Ni, Pb, Pt
Mg, Zn, Ti, Zr, Br, Cd
A iron (below 910°C and between 1400 to 1539°C), W
All of the above
Heavy duty leaf and coil springs contain carbon of the following order
0.2 %
0.5 %
0.8 %
1.0 %
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
Cold rolled steel sheets contain carbon of the following order
0.1 %
0.2 %
0.4 %
0.6 %
In basic Bessemer process, the furnace is lined with
Silica bricks
A mixture of tar and burnt dolomite bricks
Both (A) and (B)
None of these
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
Macrostructure of a material is, generally, examined by
Naked eye
Optical microscope
Metallurgical microscope
X-ray techniques
Normalising of steel is done to
Refine the grain structure
Remove strains caused by cold working
Remove dislocations caused in the internal structure due to hot working
All of the above
Connecting rod is usually made of
Aluminium
Low carbon steel
Medium carbon steel
High carbon steel
Which of the following has highest specific strength of all structural materials?
Magnesium alloys
Titanium alloys
Chromium alloys
Magnetic steel alloys