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
Correct Answer :
B. Increases hardness and brittleness
Related Questions
German silver contains
1% silver
2% silver
5% silver
No silver
The composition of silver solder is
Silver, copper, zinc
Silver, tin, nickel
Silver, lead, zinc
Silver, copper, aluminium
The usual composition of a soldering alloy is
Tin, lead and small percentage of antimony
Tin and lead
Tin, lead and silver
Tin and copper
The metal suitable for bearings subjected to light loads, is
Silicon bronze
White metal
Monel metal
Phosphor bronze
Which of the following statement is incorrect about duralumin?
It is prone to age hardening
It can be forged
It has good machining properties
It is lighter than pure aluminium
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
Pearlite consists of
13% carbon and 87% ferrite
13% cementite and 87% ferrite
13% ferrite and 87% cementite
6.67% carbon and 93.33% iron
Solder is an alloy consisting of
Tin, antimony, copper
Tin and copper
Tin and lead
Lead and zinc
Melting point of iron is
1539°C
1601°C
1489°C
1712°C
The presence of sulphur in pig iron makes
It easily machinable
It brittle
It hard
The casting unsound
Corrosion resistance of steel is increased by adding
Chromium and nickel
Nickel and molybdenum
Aluminium and zinc
Tungsten and sulphur
The aluminium alloy, mainly used, for anodized utensil manufacture, is
Duralumin
Y-alloy
Magnalium
Hindalium
Gamma iron exits at following temperature
Room temperature
Near melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
The basic constituents of Hastelloy are
Aluminium, copper etc.
Nickel, molybdenum etc.
Nickel, Copper, etc.
All of the above
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
In mottled cast iron, carbon is available in
Free form
Combined form
Nodular form
Partly in free and partly in combined state
Materials after cold working are subjected to following process to relieve stresses
Hot working
Tempering
Normalising
Annealing
Which of the following pipes is least corrosion resistant?
Brass
Mild steel
Cast iron
Wrought iron
Dye penetrant method is generally used to locate
Core defects
Surface defects
Superficial defects
Temporary defects
Iron is
Paramagnetic
Ferromagnetic
Ferroelectric
Dielectric
Which of the following statement is correct?
The product produced by blast-furnace is called cast iron
The pig iron is the name given to the product produced by cupola
The cast iron has high tensile strength
The chilled cast iron has no graphite
Which is false statement about case hardening? Case hardening is done by
Electroplating
Cyaniding
Induction hardening
Nitriding
The crystal structure of gamma iron is
Body centered cubic
Face centred cubic
Hexagonal close packed
Cubic structure
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
When the steel is normalised, its
Yield point increases
Ductility decreases
Ultimate tensile strength increases
All of these
Balls for ball bearings are made of
Cast iron
Mild steel
Stainless steel
Carbonchrome steel
Constantan an alloy used in thermocouples is an alloy of
Copper and tin
Copper and zinc
Copper and iron
Copper and nickel
The following element can't impart high strength at elevated temperature
Manganese
Magnesium
Nickel
Silicon
Which of the following material has maximum ductility?
Mild steel
Copper
Nickel
Aluminium
The machinability of aluminium increases when __________ is added to aluminium.
Copper
Magnesium
Silicon
Lead and bismuth