Vol. 15 No. 1 (1982)

. An investigation into the influence of stress and/or strain on the tempering of SAE 4340 martensitic steel is being done. The as-quenched steel is tempered at several temperatures (100° - 600°C) with and without the influence of stress. The resulting changes in hardness and structure were then followed by microhardness measurements and electron microscopy. The primary variables of interest in this work are hardening conditions, tempering time, tempering temperature, stress, and strain during tempering. From the experimental result it appears that the hardness of steel SAE 4340 tempered…