How about tempering No. 45 round bar?
Quenching and tempering is the double heat treatment of quenching and high temperature tempering, the purpose is to make the workpiece have good comprehensive mechanical properties.
Quenched and tempered steel has two major categories: carbon quenched and tempered steel and alloy quenched and tempered steel. Carbon steel or alloy steel, the control of carbon content is relatively strict. If the carbon content is too high, after quenching and tempering the strength of the workpiece is high, but the toughness is not enough, such as carbon content is too low, toughness and lack of strength. In order to make the quenched and tempered parts get good comprehensive performance, the total carbon content is controlled at 0.30~0.50%.
During quenching and tempering, the whole section of the workpiece is quenched and the microstructure of the workpiece is obtained with fine acicular quenched martensite. By tempering at high temperature, the microstructure with uniform tempered bainite is obtained. It is impossible for a small factory to do metallographic analysis of each furnace. It is generally used only for hardness testing. That is to say, the hardness of the quenched material must be reached by the quenching hardness of the material, and the hardness after tempering shall be checked according to the requirements of the drawing.
