METHOD OF INVESTIGATION OF CONVERSIONS AT THERMAL TREATMENT Russian patent published in 1997 - IPC

FIELD: mechanical engineering. SUBSTANCE: invention concerns investigation of kinetics of structural and phase conversions when thermally treating mainly large parts, for example, power generating units, metallurgical and press equipment including hammer dies of constructional and high-alloying steels with reduced rate of perlite conversion. Invention aims at investigating interrelated hardening and tempering conditions with no data on isothermal and thermokinetic conversions to justify reduced heating duration when tempering large parts. Method consists in that austenization of sample is fulfilled in saturation conditions simulating real aging times when heating for hardening real sections and batches of parts, whereupon sample is cooled in the same furnace to the end of perlite conversion stability range and then is cooled in magnetometer furnace to a partial martensite conversion, the number and parameters of cooling and heating steps being chosen in dependence on real process conditions. EFFECT: facilitated investigation process.