Topic: Material Science
Hardness will be highest after which of the following heat treatment process?
- A. Furnace cooling
- B. Air cooling
- C. Oil quenching
- D. Water quenching
Answer: D. Water quenching
Explanation: Hardness will be highest after water quenching. The rate of cooling decides the hardness of the alloy and this is different for different fluids used because of the difference in the thermal conductivities, the specific heats and the heats of vaporization of these mediums.