D-And F-Block Elements Ques 147
Question: Railway wagon axles are made by heating rods of iron embedded in charcoal powder. The process is known as
[CPMT 1972; DCE 2000; KCET 2003; UPSEAT 2001]
Options:
A) Case hardening
B) Sherardizing
C) Annealing
D) Tempering
Show Answer
Answer:
Correct Answer: A
Solution:
Case hardening: The process of hardening the surface of wrought iron by depositing a surface layer of steel on it is called case-hardening it is done by heating wrought iron in contact with potassium Ferro cyanide. Alternatively, case hardening can also be done by heating wrought iron with charcoal and then plunging it a suitable oil.
