Age-hardening is related with
Stainless steel
Gun metal
German silver
Duralumin
Correct Answer :
D. Duralumin
Related Questions
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
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
Thermoplastic materials are those materials which
Are formed into shape under heat and pressure and results in a permanently hard product
Do not become hard with the application of heat and pressure and no chemical change occurs
Are flexible and can withstand considerable wear under suitable conditions
Are used as a friction lining for clutches and brakes
The alloying element which can replace tungsten in high speed steels is
Nickel
Vanadium
Cobalt
Molybdenum
The portion of the blast furnace below its widest cross-section is called
Hearth
Stack
Bosh
Throat
Which of the following elements does not impart hardness to steel?
Copper
Chromium
Nickel
Silicon
Which of the following is added in low carbon steels to prevent them from becoming porous?
Sulphur
Phosphorus
Manganese
Silicon
Iron ore is, usually, found in the form of
Oxides
Carbonates
Sulphides
All of these
In induction hardening ________ is high.
Current
Voltage
Frequency
Temperature
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
The alloying element which reduces the formation of iron sulphide in steel is
Chromium
Nickel
Vanadium
Manganese
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
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
Malleability of a material can be defined as
Ability to undergo large permanent deformations in compression
Ability to recover its original form
Ability to undergo large permanent deformations in tension
All of the above
The material in which the atoms are arranged chaotically, is called
Amorphous material
Mesomorphous material
Crystalline material
None 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
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
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
Chilled cast iron has
No graphite
A very high percentage of graphite
A low percentage of graphite
Graphite as its basic constituent of composition
German silver contains
1% silver
2.5% silver
5% silver
10% silver
The following element can't impart high strength at elevated temperature
Manganese
Magnesium
Nickel
Silicon
Perminvar alloy having constant permeability is an alloy of
Nickel, copper and iron
Nickel, copper and zinc
Copper, nickel and antimony
Iron, zinc and bismuth
Cast iron is characterised by minimum of following percentage of carbon
0.2 %
0.8 %
1.3 %
2 %
Malleable cast iron is produced
By adding magnesium to molten cast iron
By quick cooling of molten cast iron
From white cast iron by annealing process
None of these
In low carbon steels, presence of small quantities of sulphur improves
Weldability
Formability
Machinability
Hardenability
Drop forging dies contain carbon of the order of
0.1 to 0.2 %
0.25 to 0.5 %
0.6 to 0.7 %
0.7 to 0.9 %
In nodular iron, graphite is in the form of
Cementite
Free carbon
Flakes
Spheroids
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
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
The following types of materials are usually the most ductile
Face centred cubic lattice
Body centred cubic lattice
Hexagonal close packed lattice
All of the above