PROCEDURE FOR THERMAL TREATMENT OF PARTS Russian patent published in 2011 - IPC C21D1/25 C21D9/40 C21D9/24 C21D1/78 

FIELD: metallurgy.

SUBSTANCE: part out of alloyed steel of 2-5 mm thickness and 150-400 mm diametre is subjected to quenching in free state and to tempering in compressed form in special devices to reduce warping to 0.1-0.15 mm at maintaining strength and flexibility. Also, upon quenching the part is tempered at temperature below line of commencement of martensite transformation (Mc). Upon grinding the part is subjected to stabilised tempering at temperature above line of commencement of martensite transformations (Mc) obtaining troostite structure and required hardness.

EFFECT: reduction of deformation by plane below 0,2 mm.