METHOD FOR THERMOCYCLIC TREATMENT OF STEELS Russian patent published in 2018 - IPC C21D1/25 C21D1/06 C21D1/42 

FIELD: metallurgy.

SUBSTANCE: at least two heating cycles are performed for quenching to austenite homogenization temperature and cooling at rate providing martensitic transformation and tempering with heating at a rate higher than 50°C/sec up to a temperature not higher than Ac₁. At the first cycle, heating is carried out up to austenization temperature with holding till complete homogenization of austenite, at the second and subsequent cycles, high-speed heating is carried out under hardening at the rate of 50°C/sec without soaking to the temperature, providing austenite homogenization, the tempering temperature in each subsequent cycle is lower than in the previous one. The last tempering is carried out at a temperature ensuring the required properties of steel.

EFFECT: extended service life of machine parts and tools made of alloyed, low-alloyed and carbon steels.

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