STEEL ELEMENT, METHOD OF ITS THERMAL TREATMENT AND METHOD OF ITS RECEIVING Russian patent published in 2009 - IPC C21D9/32 C23C8/20 C21D1/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to thermal treatment field. Method includes stage of cementation a1 at decreased pressure - carbonisation of steel element in carbonising gas at decreased pressure, stage of cooling a2 at decreased pressure - cooling of steel element after stage of cementation a1 at decreased pressure in cooling gas, pressure of which is reduced up to level lower than atmospheric pressure, and stage of tempering a3 - heating of external part of cooled part of steel element with usage of energy of high density. Cooling stage at decreased pressure is preferentially implemented at blending of cooling gas at condition that pressure of cooling gas is reduced up to level lower than atmospheric pressure. Cooling stage at decreased pressure is preferentially implemented at least starting from the moment up to which it is started structural change of steel element because of cooling up to moment of total completion of structural change. Pressure of cooling gas during cooling stage at decreased pressure is from 0.1 up to 0.65 bar.

EFFECT: prevention of deformation of steel element and reduction of duration of its treatment.

29 cl, 9 ex, 32 dwg