PROCEDURE FOR THERMAL ANTIFLOCCULANT PROCESSING OF FORGED PIECES Russian patent published in 2010 - IPC C21D3/06 

FIELD: metallurgy.

SUBSTANCE: forged pieces are cooled to 473-773 K in thermos of retarded cooling at cooling rate 12-17 K/h or in air at rate 80-120 K/h. Also, reduction of duration of furnace heating is determined from equation: Δτ_f=0.07T_f/W_f + 0.28T_tr/W_f, where: Δτ_f - equivalent time of anti-flocculant processing at cooling forged pieces after forging, hours, T_f=1123-1223 K is temperature of forging finish; T_tr=933-953 K is temperature of transformation of γ-phase into ferrite-pearlite structure, and W_f is rate of forged pieces cooling after forging. Further, a forged piece is heated in furnace to 923-1103 K, is isothermally conditioned and cooled in the thermos of retarded cooling at rate 10-15 K/h. Also reduction of time of thermal treatment duration is determined from equation: Δτ_furn=(0.36-0.37)T₀/W_f, where: Δτ_furn is equivalent time of anti-flocculant processing at forged piece cooling in the thermos upon processing in the furnace , hour; T₀=923-1103 K is temperature of forged pieces heating in furnace; W_f=10-15 K/h is rate of forged pieces cooling in the thermos. When there are processed forged pieces of diametre not exceeding 500 mm, temperature in furnace is raised to 1023-1103 K 15-45 minutes before end of processing. Temperature of forged pieces heating is accepted as T₀=923-953 K at evaluating Δτ_furn.

EFFECT: reduced duration of after forging treatment.

4 cl, 5 ex