The normalizing of steel
Normalizing is a heat treatment method in which steel is heated above the critical temperature, so that all steel is transformed into uniform austenite, and then cooled naturally in the air. It can eliminate the mesh cementite of hypereutectoid steel, for hypoeutectoid steel normalizing can refine the lattice, improve the comprehensive mechanical properties, for not high requirements of parts with normalizing instead of annealing process is more economical.
Hardening of steel
Quenching is a heat treatment method in which the steel is heated to a critical temperature above, held for a period of time, and then quickly put into the quenching agent to make its temperature drop suddenly and cool rapidly at a speed greater than the critical cooling rate to obtain the unbalanced structure dominated by martensite. Quenching can increase the strength and hardness of steel, but reduce its plasticity. Quenching agents commonly used in quenching are: water, oil, alkali water and salt solution.
