Preparation method of nickel-based wrought superalloy wheel disk forgings used at high temperature

A preparation method of nickel-based wrought superalloy wheel disk forgings, comprising following steps:

• Step 1:
• weighing raw materials according to a composition proportion wherein the raw materials comprise by weight percentage:
• C:
• 0.01˜0.08%, W:
• 6.5˜8.0%, Cr:
• 7.5˜11.0%, Mo:
• 1.5˜3.5%, Co:
• 14.5˜17.5%, Ti:
• 1.0˜2.0%, Al:
• 4.0˜5.5%, Nb:
• 1.0˜2.0%, Zr:
• 0.005˜0.05%, Mg:
• 0.005˜0.05%;
• Ce:
• 0.001˜0.05%, B:
• 0.005˜0.05% and Fe:
• 0.01˜1.5%, and balance of Ni;
• and the raw materials further comprise impurity elements:
• P≤0.015%, Mn≤0.5%, Si≤0.5%, S≤0.015%, O≤0.005%, N≤0.01%, Ag≤0.005%, Ca≤0.01%, Sn≤0.01%, Pb≤0.001%, Cu≤0.5%, Ta≤0.5% and V≤0.5%;
• step 2:
• smelting the raw materials into a primary alloy ingot by vacuum induction smelting comprising the following steps of:
• evacuating, smelting, refining and tapping, demoulding, subjecting the primary alloy ingot to high-temperature stress relief annealing and electroslag remelting refining to obtain a secondary alloy ingot, demoulding, subjecting the secondary alloy ingot to low-temperature stress relief annealing and vacuum consumable remelting refining to obtain a tertiary alloy ingot, thereby obtaining an alloy ingot;
• in the evacuating process, the vacuum degree is 10-100 Pa;
• in the process of the smelting stage, the temperature is controlled to be 1300° C.-1650° C.;
• in the refining process, the temperature is controlled to be 1400° C.-1600° C., and the vacuum degree is 1-20 Pa;
• in the tapping process, the temperature is controlled to be 1420° C.-1590° C., and 10,000-50,000 Pa argon gas is filled for protection;
• after casting, cooling is performed for 0.5-3 h, and demoulding is performed to obtain a primary alloy ingot;
• and the primary alloy ingot is subjected to high-temperature stress relief annealing treatment, wherein the temperature is increased to a high-temperature stress relief annealing temperature T at a rate of 10-50° C./h, the temperature of T is the total melting temperature of γ′ phase Tγ′±50° C., and Tγ′ is calculated from the measured composition of the alloy using the commercial software Jmatpro;
• wherein the temperature is increased to a low-temperature stress relief annealing temperature T at a rate of 10-50° C./h, the temperature of T is Tγ′−100 to Tγ′−250° C., and Tγ′ is calculated from the measured composition of the alloy using the commercial software Jmatpro;
• step 3:
• performing a first high-temperature homogenizing annealing on the alloy ingot obtained in Step 2 to obtain a high-temperature homogenizing annealed alloy, wherein the first high-temperature homogenizing annealing comprises heating, heat preservation and cooling processes, the heating rate is controlled to be 15-60° C./h, the temperature of the heat preservation is 1150-1250° C., and the time of the heat preservation is 24-72 h;
• and the cooling rate is controlled to be 5-55° C./h;
• and performing heating, forging and cogging on the alloy to obtain a bar, and subjecting the bar to a second high-temperature homogenizing annealing to obtain wheel disk forgings;
• wherein the temperature is increased to the second high-temperature homogenizing annealing temperature T at a rate of 10-50° C./h, and the temperature of T is Tγ′±30° C., Tγ′ is calculated from the measured composition of the alloy using the commercial software Jmatpro;
• step 4:
• cutting the bar obtained in Step 3 according to the weight of the wheel disk forgings to obtain a cut bar, and subjecting the cut bar to blank making and die forging to obtain an alloy wheel disk forging, wherein the weight of the cut bar is 115-145% of the weight of the wheel disk forging, the height-diameter ratio of the cut bar is controlled to be 1.5-3.0;
• and
• step 5:
• performing heat treatment on the alloy wheel disk forgings obtained in Step 4 to obtain nickel-based wrought superalloy wheel disk forgings, wherein the heat treatment comprises a solid solution treatment, an intermediate aging treatment and an aging treatment, the solid solution treatment method comprises performing heat preservation at 1150-1220° C. for 2-10 h, the intermediate aging treatment method comprises performing heat preservation at 1000-1150° C. for 2-10 h;
• and the aging treatment method comprises performing heat preservation at 760° C.-920° C. for 8-32 h.