For heat treatment, it includes a series of operations such as quenching, tempering, annealing and surface hardening. Hot rolled flat steel can change the physical properties of metal by heating and cooling.
Hot rolled flat steel becomes brittle after quenching. To eliminate its brittleness, tempering treatment can be directly adopted. During tempering, hot rolled flat steel parts shall be reheated to appropriate temperature or color, and then cooled. Although tempering process can slightly reduce the hardness of hot rolled flat steel, it will increase its toughness and reduce its brittleness.
