Question:-
Consider the following quenching media :
1. Oil
2. Water
3. Water + NaOH
4. Brine
The correct sequence of these media in order of increasing hardness of steel undergoing heat treatment is
Option (A)
1, 3, 2, 4
Option (B)
2, 1, 3, 4
Option(C)
1, 2, 3, 4
Option(D)
4, 3, 2, 1
Correct Option:
(C)
Question Solution:
The hardness of steel will depend upon the rate of cooling. Faster is the cooling rate harder is the steel
Decreasing cooling rate sequence
(1) Brine – Salt will be NaCl, NaOH, CaCl2
(2) Water + NaOH
(3) Water
(4) Oil
question-answer-faq-6627