Explain the terms-(1) Quenching (2) Annealing (3) Tempering

Explanation

i) Quenching - If a steel article is heated to redness .(1123, ~K). and then suddenly cooled by plunging in water or oil, the heat treatment of steel is called quénching.
ii) Annealing - If steel is heated to a temperature well below red hot and then cooled slowly, the process is called annealing.
iii) Tempering - When the quenehed steel is heated to a temperature of about .550 cdot K. .and kept for some time- at the same temperature and then cooled slowly. steel obtained is quite hard but brittle , This treatment is catled tempering.