PROCEDURE FOR THERMAL TREATMENT OF ITEMS OUT OF STEEL AND ALLOYS Russian patent published in 2011 - IPC C21D11/00 C21D1/55 G01N25/18 C21D9/04 

FIELD: metallurgy.

SUBSTANCE: procedure for production of metal items with specified structure condition after thermal treatment consists in laboratory determination of temperature curve for heat treatment of material sample of metal item. This curve should facilitate obtaining specified structure state of item material. Further, the procedure consists in defining intervals of thermal treatment under conditions of following modes of thermal treatment corresponding to obtained temperature curve, in considering cooling effect on surface of item with control of heat flow along surface of item in each interval of heat treatment, and in facilitating compliance of obtained and specified temperature curves by method of iteration in volume of item with consideration of energy release in volume of item during physical and chemical conversion. Heat flow is determined out of expression: Q = [(H'+H₀'-qΔm)-(H+H₀)]/Δt, J/f, where H and H₀ are initial enthalpies of phases, J, H' and H₀' are enthalpies of phases, J, in a time interval, Δt, s; Δm is change of weight of phases, kg, during specified interval of time; q is specific energy release, J/kg.

EFFECT: stabilisation of process effects, minimisation or complete avoiding rejects during production of items with required mechanical properties.

1 ex, 1 dwg