METHOD OF HEAT TREATMENT OF PROFILED METALLIC SURFACES Russian patent published in 2008 - IPC C21D1/09 C21D9/38 

FIELD: metallurgy; heat treatment.

SUBSTANCE: said utility invention relates to heat treatment, namely, to processes of iron carbon alloy surface hardening with high-energy plasma flows, and may be used during treatment of indented rebar finishing stand rolls. The method involves single heating of a profiled metallic surface with a plasma jet to a temperature of (0.7-0.95)T_MELT where T_MELT is the material melting temperature; the central axis of the plasma jet is located at the line of the vertical diameter of the finisher, and the plasmatron nozzle diameter is calculated using the ratio d_calc>d_n>0.5d_calc where d_calc, cm, is the calculated diameter of the rebar being rolled, d_n, cm, is the plasma nozzle diameter, the plasma jet treatment heat input is calculated as q/V=l7500-19000 Wxs/cm³ where: q, W/cm², is the heat flux power density; V, cm/s, is the treatment area displacement rate, and the distance from the plasma nozzle section centre to the groove surface is selected within 25-31 mm. The use of this method allows to increase the roll resistance by 1.8 times as compared to the rated resistance, by forming a hardened surface layer with high hardness, optimum structure and thickness.

EFFECT: increased resistance of treated material due to formation of hardened surface layer with high hardness, optimum structure and thickness.

1 ex, 6 dwg, 1 tbl