FORMATION OF THE MICROSTRUCTURE AND PROPERTIES OF HEAT-HARDENABLE STEELS OF THE 15G2MFTR TYPE IN ISOSCLERIC TEMPERING

An optimum set of properties in heat-hardenable high-strength weldable steels of the 15G2MFTR type is attained after quenching and tempering at 650 - 680 degrees C for 1 h. The tempering operation (to a specifi ed level of strength) can be intensified by a certain increase in the heating temperature, thereby decreasing the hold time, which makes the heat treatment less expensive. This work concerns the possibility of replacing the standard tempering regime for steels 15G2MFTR and 15G2Kh NMFTR by an accelerated tempering at a higher temperature.