FIELD: methods of heat treatment of nickel-base superalloys. SUBSTANCE: superalloy has the following chemical composition, wt.%: Cr, 11-14; Co, 8-17; Mo, 6-8; Ti, 4-5; Al, 4-5; Nb, ≤ 1.5; Hf, ≤ 1; C, B, Zr, ≤ 5•10-4 each; Ni, the balance up to 100%; or Cr, 12-15; Co, 14.5-15.5; Mo, 2-4.5; W, ≤ 4.5; Al, 2.5-4; Ti, 4-6; Hf, ≤ 0.5; C, 1•10-4-3•10-4; B, 1•10-4-5•10-4; Zr, 2•10-4-7•10-4; nickel, the balance. Method includes operation of hot forging at temperature between solidus temperature point of γ′-phase of superalloy of minus 95 C and solidus temperature point of γ′-phase of superalloy of minus 45 C rate of deformation from 5•10-5/s to 2•10-2/s and with degree of reduction above 0.1; subsequent intermediate heat treatment at temperature between solidus temperature point of γ′-phase of superalloy of minus 95 C and solidus temperature point of γ′-phase of superalloy of minus 30 C for 1 to 24 h; and heat treatment at temperature between solidus temperature point of γ′-phase of superalloy of plus 5 C and solidus temperature point of γ′-phase of superalloy of plus 25 C for 1 to 4 h. According to the second version of the method, after hot forging, isothermal holding is effected at temperature between solidus temperature point of γ′-phase of superalloy of minus 95 C and solidus temperature point of γ′-phase of superalloy of minus 30 C for 1 to 60 min beginning from the moment with metal at forging temperature. According to the third version, after isothermal holding, heat treatment is carried out at temperature between solidus temperature point of γ′-phase of superalloy of minus 95 C and solidus temperature point of γ′-phase of superalloy of minus 30 C for 1 to 24 h. EFFECT: higher resistance of alloys to cracking at high temperatures. 3 cl, 5 dwg
