High carbon iron
Highly resistance to acid corrosion
Malleable & ductile; and hence is used for chain links, hooks & couplings
An alloy of iron, chromium & carbon
✅ The correct answer is option C.
Materials and Construction MCQs
432. __________ iron is produced, when molten pig iron is chilled suddenly.
White cast
Grey cast
Wrought
None of these
✅ The correct answer is option A.
433. Steel will respond to hardening by heat treatment processes, only when the minimum carbon content in it is __________ percent.
0.02
0.2
0.35
0.5
✅ The correct answer is option B.
434. All materials obey Hooke’s law within elastic limit. When elastic limit is reached, the tensile strain
Increases very quickly
Decreases very quickly
Increases in proportion to stress
Decreases in proportion to stress
✅ The correct answer is option A.
435. Which of the following undergoes granular fracture?
Wrought iron
Steel
Cast iron
None of these
✅ The correct answer is option B.
436. The increase in hardness of metal due to its cold working is termed as the __________ hardening.
Work
Age
Induction
Flame
✅ The correct answer is option A.
437. Iron rust is
Ferrous oxide
Hydrated ferric oxide
Powdered iron
Ferric sulphide
✅ The correct answer is option B.
438. __________ is not a case hardening process.
Carburising
Nitriding
Cyaniding
Annealing
✅ The correct answer is option D.
439. Lead pipes are not safe for carrying drinking water because water containing dissolved oxygen attacks lead thereby forming poisonous Pb (OH)2. Lead pipes are readily corroded by
Dilute HCI
Acetic acid
Concentrated H₂SO₄
None of these
✅ The correct answer is option B.
440. To improve the machinability of steel, it is generally subjected to
Spheroidising
Tempering
Normalising
Annealing
✅ The correct answer is option A.