PROCESS OF THERMOCYCLIC TREATMENT OF TOOL STEEL Russian patent published in 1999 - IPC

FIELD: metallurgy, thermal treatment of steel while manufacturing tools and parts of machines. SUBSTANCE: multiple heating of samples above A_Cl by 130-170 C with rate of 6-35 deg/s is carried out, cycle of cooling to below A_Cl is conducted in melt of salts to temperature 680-750 C with holding at this temperature for 3-9 min, cooling in oil after heating of last cycle is performed at temperature 200-400 C. Specified process provides for diminished time of thermocyclic treatment, for enhanced hardness and strength properties with maintenance of high impact elasticity. EFFECT: increased operational strength of tools under dynamic loads. 1 tbl