CN113732481B - Method for improving diffusion bonding performance of powder high-temperature alloy double-spoke plate turbine disc - Google Patents

Abstract

The invention discloses a method for improving the diffusion bonding performance of a powder superalloy double-spoke plate turbine disc, which comprises the following steps: the method comprises the following steps of single piece pre-preparation process, cleaning, assembly, furnace entering, diffusion connection pre-welding, vacuum solid solution treatment, aging treatment, metallographic section inspection, turning to remove allowance, and ultrasonic inspection; the influence of diffusion bonding and solid solution treatment on the diffusion bonding quality of the powder high-temperature alloy and the performance of the joint and the base material is researched, the hot working process route of the whole flow is matched and adjusted, the diffusion bonding pre-combination process curve is optimally designed, the post-welding adjustment heat treatment process is formulated, the high-quality bonding of the powder high-temperature alloy is realized, the performance damage of the joint and the base material is eliminated, and the final use performance of the double-radial-plate turbine disc is ensured.

Description

Method for improving diffusion bonding performance of powder high-temperature alloy double-spoke plate turbine disc

Technical Field

The invention relates to the technical field of manufacturing of turbine disks of aero-engines, in particular to a method for improving diffusion bonding performance of a powder high-temperature alloy double-spoke plate turbine disk.

Background

The turbine disk is a critical component of an aircraft engine. The double-spoke plate turbine disk is a novel turbine disk which is formed by welding two approximately symmetrical half disks and is provided with an inner cavity; as shown in figure 1, during work, the cold air collected by the cooling holes of the turbine blades flows to the cavity in the turbine disc through the air inlet hole in the bottom of the mortise at the edge of the disc to cool the blades and the inner part of the disc body, so that the cooling mode that the cold air of the traditional turbine disc can only flow through the disc surface is changed, the cooling air consumption is greatly reduced, the service life of the wheel disc is prolonged, and the cooling device is one of the key development directions of international advanced high-performance engines.

A design scheme of a powder high-temperature alloy double-spoke plate turbine disc is provided domestically, and the following problems are solved:

(1) the structure design is compact, the edge part of the disc needs to be welded, the distance between two radial plates of the disc core is less than 10mm, the inner cavity cannot be processed after being welded, and the diffusion connection is the only method for realizing the allowance-free forming of the inner cavity;

(2) the third-generation powder high-temperature alloy is adopted, the alloy is the preferred material of a hot end part of a new-generation aero-engine, and the alloy diffusion bonding public research data is not available at home and abroad, so that the basic research is insufficient;

the foreign dual-spoke plate turbine disk adopts an intermediate layer diffusion connection method, the diffusion connection joint interface cannot be eliminated, the structure difference is large, the joint area performance difference is large, the reliability is poor, and the service life is short;

patent CN201611139377.0 proposes a method for connecting double-spoke plate turbine disks by pressurization and diffusion, and patent CN202011106872.8 proposes a method for welding double-spoke plate turbine disks by nickel plating of a welding surface, pre-diffusion and hot isostatic pressing; however, neither of the above patents provides a specific process.

Patent CN202011114296.1 proposes a method for pressure diffusion bonding of a double-web turbine disk, which gives specific process parameters and can be used for trial production of double webs.

Comprehensive analysis of domestic and foreign patent and literature data, about the diffusion connection of the powder high-temperature alloy double-web turbine disk, the following problems exist:

(1) the diffusion bonding temperature of the high-temperature alloy is generally 80-85% of the melting point, but as the powder high-temperature alloy elements are more than 10, the alloying degree is high, gamma' strengthening phases exist in crystal grains and crystal boundaries, the high-temperature stability of an alloy structure is excellent, and even if diffusion bonding is carried out in the temperature range, no obvious structure transformation exists, the diffusion bonding interface remains, and the high-temperature fatigue performance of a joint is influenced; in order to improve the high-temperature fatigue performance, the diffusion connection temperature needs to be improved or the connection time needs to be prolonged, and the two modes are accompanied with the growth of an alloy structure and the dissolution of gamma' phase, so that the comprehensive performance of a connection joint and a base material is influenced;

(2) the genetic research on the material structure performance through multiple thermal cycles is less at home and abroad, the hot processing arrangement of solid solution treatment → high-temperature diffusion connection → vacuum aging treatment is commonly adopted during the diffusion connection of high-temperature alloy, and the heat treatment process characteristic of the diffusion connection thermal cycle is not considered; when powder high-temperature alloy is in diffusion connection, the thermal cycle of solution treatment is equivalently carried out, the gamma' -phase is dissolved, crystal grains grow up, and the alloy performance is damaged; in order to reduce or avoid the damage of the alloy performance, a higher cooling speed is needed after the diffusion connection heat preservation; compared with a heat treatment furnace, the maximum argon filling pressure of the diffusion connection equipment is only 1.4bar, a complex mechanism in the heating furnace has large heat absorption and heat release quantity, the flow of cooling gas is also disturbed, and the cooling efficiency is far lower than that of the heat treatment furnace; resulting in insufficient supercooling degree, less gamma' phase precipitation amount and larger size, and greatly influencing the comprehensive performance of the joint and the base material.

In conclusion, the prior art cannot meet the development requirement of a high-performance powder high-temperature alloy double-spoke turbine disk.

Disclosure of Invention

In order to solve the technical problem, a method for improving the diffusion bonding performance of a powder superalloy double-spoke plate turbine disc is provided, and the specific technical scheme is as follows:

a method for improving diffusion bonding performance of a powder superalloy double-spoke plate turbine disk comprises the following steps:

the method comprises the following steps: single-piece pre-preparation process

The blank of the part to be welded is a forged powder high-temperature alloy; carrying out rough machining by adopting turning; processing the surfaces to be welded and the reference surface by grinding to ensure that the flatness and the parallelism of the reference surface and the surfaces to be welded are less than or equal to 0.03 mm; the final processing of the surface to be welded is carried out by adopting precision grinding, so that the surface roughness of the surface to be welded is less than or equal to 0.4 mu m, and the surface to be welded has no burn, ablation or other foreign matters;

step two: cleaning of

Degreasing by using absorbent cotton or white cotton cloth, then putting the to-be-welded surface of the to-be-welded part upwards into an ultrasonic cleaning machine for cleaning, wherein a cleaning solvent is deionized water, distilled water, a water-based cleaning agent or alcohol, and any one of the four is selected, and no water stain residue exists on the to-be-welded surface after cleaning;

step three: combination of

Aligning and fitting two workpieces to be welded, positioning by using a positioning pin, and checking that the gap between the two surfaces to be welded is less than or equal to 0.02 mm;

step four: into the furnace

Placing a titanium-zirconium-molybdenum alloy mould on a diffusion connection equipment platform, sequentially placing a component to be welded and a titanium-zirconium-molybdenum alloy upper mould on the titanium-zirconium-molybdenum alloy mould, and then arranging a graphite limiting column around the component to be welded, so that the graphite limiting column is 0.08 +/-0.03 mm lower than the upper surface of the titanium-zirconium-molybdenum alloy upper mould, and a device pressure plate is lowered to tightly press the titanium-zirconium-molybdenum alloy upper mould; closing the furnace door and vacuumizing until the vacuum pressure in the furnace is less than 1 x 10^-4mbar and below;

step five: diffusion bonded pre-solder joint

Setting the diffusion bonding pressure to be 10-20 MPa, heating to 800 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 60-120 min; then heating to 980 ℃ at a heating rate of not more than 5 ℃/min, adjusting the diffusion bonding pressure to 1 MPa-2 MPa, then heating to 1030 +/-10-1100 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 120 min-240 min; then adjusting the diffusion bonding pressure to be not more than 0.5MPa, keeping the vacuum state, cooling to be below 80 ℃ along with the furnace, and discharging;

in the temperature rise process, the temperature rise speed is not more than 5 ℃/min so as to ensure uniform temperature inside and outside the to-be-welded part and reduce deformation of the to-be-welded part caused by thermal stress generated by temperature difference;

in diffusion bonding, the two surfaces to be bonded must be brought into intimate contact. At the initial stage of the diffusion bonding process, the microcosmic particles on the surface to be welded are contacted and generate microcosmic plastic deformation under the action of pressure, the contact particles at the initial stage are flattened along with the increase of the microcosmic plastic deformation, the number of the microcosmic particles which can be in close contact is gradually increased, and the contact area is gradually enlarged along with the continuous occurrence of the microcosmic deformation, so that the connection between crystal grains, namely diffusion bonding, is formed; the surfaces to be welded of the welding parts are finally treated by grinding, and compared with turning and grinding, the surface roughness value is lower, which means that the quantity of micro particles which can be tightly contacted between the two surfaces to be welded is increased in the diffusion connection process, and in order to fully utilize the promotion effect of the micro particle contact and micro plastic deformation on the closure of a diffusion connection interface in the diffusion connection process, higher diffusion connection pressure is needed before the temperature is increased to 980 ℃;

the forged powder high-temperature alloy has fine crystal grains, and is easy to generate macroscopic plastic deformation at 1000 ℃, and in order to ensure the dimensional precision of a component to be welded, the invention adopts graphite column for limiting; if the to-be-welded part is compressed to be as high as the graphite column before formal connection, the promotion effect of the diffusion connection pressure on the welding of the connection interface is weakened, so that the diffusion connection pressure is adjusted to be 1-2 MPa at 980 ℃ to ensure that the to-be-welded part always bears the welding pressure effect before formal connection;

in order to avoid the performance damage of the powder superalloy connector and the matrix material, the diffusion bonding temperature cannot be higher than 1130 ℃; the diffusion bonding temperature is 1030 +/-10-1100 +/-10 ℃, good connection interface micro-hole closure can be realized within the temperature range, and higher welding rate is obtained; but because the temperature range is lower than the alloy solution treatment temperature, the alloy does not generate grain growth or recrystallization, the diffusion connection interface structure is not reconstructed, an obvious connection interface or a nanometer microscopic hole still exists, and the joint performance is poorer; the subsequent vacuum solid solution treatment is combined to ensure that the structure is changed violently, and the reconstruction of the structure of the connecting interface and the crystal penetration of the interface can be realized, so that the aims of eliminating the connecting interface and the nanoscale microscopic holes are fulfilled, and the performance of the joint is improved.

Step six: vacuum solution treatment

Heating to 800 ℃ at a heating rate of not more than 15 ℃/min, preserving heat for 60-120 min, then heating to 1130 +/-10-1160 +/-10 ℃ at a heating rate of not more than 15 ℃/min, and preserving heat for 120-300 min; after the heat preservation is finished, filling 4-6 bar of high-purity argon, starting a fan to quickly cool the weldment to below 400 ℃, then closing the fan and an argon filling system, and cooling the weldment to below 80 ℃ along with the furnace and discharging;

during the solution treatment process, the residual PPB and the initial gamma' phase in the alloy are dissolved, and the alloy crystal grains are recrystallized; in the process, the diffusion bonding interface is reconstructed, the residual microscopic holes in the interface are continuously closed under the action of recrystallization, and finally, a bonding joint without an original bonding interface and the microscopic holes is formed; the blower is started to fill argon for quick cooling, the cooling speed of a weldment is far higher than that of diffusion connection due to the fact that the mechanism in the vacuum heat treatment furnace is simple, and gamma' phases with more quantity and smaller size are precipitated in the alloy through larger supercooling degree, so that the comprehensive performance of parts is guaranteed. When the temperature is cooled to below 400 ℃, the weldment is cooled along with the furnace so as to reduce the deformation of the weldment during heat treatment;

step seven: aging treatment:

adopting secondary aging vacuum heat treatment, wherein the heat treatment system is 815 +/-10-845 +/-10 ℃, keeping the temperature for 240-480 min, cooling the furnace to below 80 ℃, and discharging the furnace; keeping the temperature at 760 +/-10 ℃ for 480-960 min, cooling the furnace to below 80 ℃, and discharging the furnace;

through secondary aging treatment, the precipitation and growth of gamma' phase are further promoted, so that the comprehensive performance of a weldment joint and a base material is improved;

step eight: metallographic sectioning test

Sampling in the allowance area, and carrying out joint metallographic examination, wherein the defects of an original diffusion connection interface and a microscopic hole are not found;

step nine: removing allowance by lathing

Turning the allowance outside the rim, radially removing the allowance of 5mm, and finely turning the reference surface of the left spoke plate to ensure that the roughness of the reference surface is less than or equal to 1.6 mu m;

step ten: ultrasonic testing

And (3) detecting from the reference surface of the left spoke plate disc by adopting water immersion ultrasonic waves, and detecting that the standard exceeding defect is not found. The invention has the beneficial effects that:

the invention relates to a diffusion bonding method for realizing allowance-free forming of an inner cavity of a double-floating-plate turbine disc, which is a unique method for realizing allowance-free forming of the inner cavity of the double-floating-plate turbine disc.

Drawings

FIG. 1 is a schematic structural view of a double-radial-plate turbine disk involved in the present invention;

FIG. 2 is a schematic structural diagram of a part to be welded of a double-radial-plate turbine disc involved in the invention;

FIG. 3 is a schematic view of a double radial plate turbine disk stack incorporating the present invention;

FIG. 4 is a cross-sectional view A-A of FIG. 3;

FIG. 5 is a photomicrograph of the joint after diffusion bonding pre-bonding in the examples;

FIG. 6 is a photomicrograph of the diffusion bonded joint after solution treatment in the examples.

In the figure: 1-plate edge, 2-left radial plate, 3-mounting edge, 4-vent hole, 5-right radial plate, 6-cavity, 7-diffusion connecting surface, 8-reference surface, 9-titanium-zirconium-molybdenum die, 10-equipment platform, 11-graphite spacing column, 12-titanium-zirconium-molybdenum upper die and 13-equipment pressing plate.

Detailed Description

The typical structure of a double-spoke turbine disk part according to the following comparative examples and embodiments is shown in fig. 1 and 5, a part to be welded of the double-spoke turbine disk is schematically shown in fig. 2, the part to be welded is a left spoke plate 2 and a right spoke plate 5 of two approximately symmetrical disk blanks with spoke plates, wherein the left spoke plate 5 is provided with a mounting edge 3; the left spoke plate 2 and the right spoke plate 5 are aligned and attached, the plate edges 1 are aligned, positioning is carried out by adopting a positioning pin, a component to be welded is formed after assembly, and a vent hole 4 and a cavity 6 are arranged between the left spoke plate and the right spoke plate; the double-spoke turbine disk group is assembled into a furnace structure as shown in figure 3.

Example 1

The method comprises the following steps: single-piece pre-preparation process

The left spoke plate 2 and the right spoke plate 5 of the blank to be welded are made of powder high-temperature alloy in a forging state, and are shown in FIG. 2; carrying out rough machining by adopting turning; processing the surface to be welded 7 and the reference surface 8 by grinding to ensure that the planeness and the parallelism of the reference surface 8 and the surface to be welded 7 are less than or equal to 0.03 mm; finishing the surface 7 to be welded by adopting precision grinding to ensure that the surface roughness of the surface 7 to be welded is less than or equal to 0.4 mu m, and the surface 7 to be welded has no burn, ablation or other foreign matters;

step two: cleaning of

Degreasing by using absorbent cotton or white cotton cloth, then upwards putting the surfaces 7 to be welded of the two parts to be welded into an ultrasonic cleaning machine for cleaning, wherein a cleaning solvent is deionized water, distilled water, a water-based cleaning agent or alcohol, and the surfaces to be welded are free of water stain residues after cleaning;

step three: combination of

Aligning and fitting two workpieces to be welded, positioning by using a positioning pin, and checking that the gap between the two surfaces to be welded is less than or equal to 0.02 mm;

step four: into the furnace

Placing a titanium-zirconium-molybdenum alloy die 9 on a diffusion connection equipment platform 10, sequentially placing a component to be welded and a titanium-zirconium-molybdenum alloy upper die 12 on the titanium-zirconium-molybdenum alloy die, then arranging a graphite limiting column 11 around the component to be welded, enabling the graphite limiting column 11 to be 0.08 +/-0.03 mm lower than the upper surface of the titanium-zirconium-molybdenum alloy upper die 12, and enabling an equipment pressing plate 13 to descend to tightly press the titanium-zirconium-molybdenum alloy upper die 12, as shown in figure 3; closing the furnace door and vacuumizing until the vacuum pressure in the furnace is less than 1 x 10^-4mbar and below;

step five: diffusion bonded pre-solder joint

Setting the diffusion bonding pressure to 10MPa, heating to 800 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 120 min; then heating to 980 ℃ at a heating rate of not more than 5 ℃/min, adjusting the diffusion bonding pressure to 2MPa, then heating to 1035 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and preserving heat for 240 min; then adjusting the diffusion bonding pressure to be not more than 0.5MPa, keeping the vacuum state, cooling to be below 80 ℃ along with the furnace, and discharging;

step six: vacuum solution treatment

Heating to 800 ℃ at a heating rate of not more than 15 ℃/min, preserving heat for 90min, heating to 1160 +/-10 ℃ at a heating rate of not more than 15 ℃/min, and preserving heat for 120 min; after the heat preservation is finished, filling 6.0bar of high-purity argon, and starting a fan to quickly cool the weldment to below 400 ℃; then, the fan and the argon filling system are closed, and the weldment is cooled to be below 80 ℃ along with the furnace and is discharged from the furnace;

step seven: aging treatment

Performing secondary aging vacuum heat treatment, wherein the heat treatment system is 815 +/-10 ℃, preserving heat for 480min, cooling the furnace to below 80 ℃, and discharging; keeping the temperature at 760 +/-10 ℃ for 960min, cooling the furnace to below 80 ℃, and discharging;

step eight: metallographic sectioning test

Sampling in the allowance area, and carrying out metallographic examination on the joint, wherein the defects of an original diffusion connection interface and a microscopic hole are not seen, as shown in figure 5;

step nine: removing allowance by lathing

Turning the allowance outside the rim, radially removing the allowance of 5mm, and finely turning the reference surface of the left spoke plate to ensure that the roughness of the reference surface is less than or equal to 1.6 mu m;

step ten: ultrasonic testing

And (3) detecting from the reference surface of the left spoke plate disc by adopting water immersion ultrasonic waves, and detecting that the standard exceeding defect is not found.

Example 2

The method comprises the following steps: single-piece pre-preparation process

The left spoke plate 2 and the right spoke plate 5 of the blank to be welded are made of powder high-temperature alloy in a forging state, and are shown in FIG. 2; carrying out rough machining by adopting turning; processing the surface to be welded 7 and the reference surface 8 by grinding to ensure that the planeness and the parallelism of the reference surface 8 and the surface to be welded 7 are less than or equal to 0.03 mm; finishing the surface 7 to be welded by adopting precision grinding to ensure that the surface roughness of the surface 7 to be welded is less than or equal to 0.4 mu m, and the surface 7 to be welded has no burn, ablation or other foreign matters;

step two: cleaning of

Degreasing by using absorbent cotton or white cotton cloth, then putting the surfaces 7 to be welded of the two parts to be welded upwards into an ultrasonic cleaning machine for cleaning, wherein a cleaning solvent is deionized water, distilled water, a water-based cleaning agent or alcohol, and no water stain residue exists on the surfaces to be welded after cleaning;

step three: combination of

Aligning and fitting two workpieces to be welded, positioning by using a positioning pin, and checking that the gap between the two surfaces to be welded is less than or equal to 0.02 mm;

step four: into the furnace

Placing a titanium-zirconium-molybdenum alloy die 9 on a diffusion connection equipment platform 10, sequentially placing a component to be welded and a titanium-zirconium-molybdenum alloy upper die 12 on the titanium-zirconium-molybdenum alloy die, then arranging a graphite limiting column 11 around the component to be welded, enabling the graphite limiting column 11 to be 0.08 +/-0.03 mm lower than the upper surface of the titanium-zirconium-molybdenum alloy upper die 12, and enabling an equipment pressing plate 13 to descend to tightly press the titanium-zirconium-molybdenum alloy upper die 12, as shown in figure 3; closing the furnace door and vacuumizing until the vacuum pressure in the furnace is less than 1 x 10 < -4 > mbar and below;

step five: diffusion bonded pre-solder joint

Setting the diffusion bonding pressure to be 20MPa, heating to 800 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 60 min; then heating to 980 ℃ at a heating rate of not more than 5 ℃/min, adjusting the diffusion bonding pressure to 1MPa, then heating to 1100 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and preserving heat for 120 min; then adjusting the diffusion bonding pressure to be not more than 0.5MPa, keeping the vacuum state, cooling to be below 80 ℃ along with the furnace, and discharging;

step six: vacuum solution treatment

Heating to 800 ℃ at a heating rate of not more than 15 ℃/min, preserving heat for 120min, then heating to 1130 +/-10 ℃ at a heating rate of not more than 15 ℃/min, and preserving heat for 300 min; after the heat preservation is finished, 4.0bar of high-purity argon is filled, and a fan is started to rapidly cool the weldment to below 400 ℃; then, the fan and the argon filling system are closed, and the weldment is cooled to be below 80 ℃ along with the furnace and is discharged from the furnace;

step seven: aging treatment

Adopting a two-stage aging vacuum heat treatment system of 815 +/-10 ℃, preserving heat for 480min, cooling the furnace to below 80 ℃, and discharging; keeping the temperature at 760 +/-10 ℃ for 480min, cooling the furnace to below 80 ℃, and discharging;

step eight: metallographic sectioning test

Sampling in the allowance area, and carrying out joint metallographic examination, wherein the defects of an original diffusion connection interface and a microscopic hole are not found;

step nine: removing allowance by lathing

Turning the allowance outside the rim, radially removing the allowance of 5mm, and finely turning the reference surface of the left spoke plate to ensure that the roughness of the reference surface is less than or equal to 1.6 mu m;

step ten: ultrasonic testing

And (3) detecting from the reference surface of the left spoke plate disc by adopting water immersion ultrasonic waves, and detecting that the standard exceeding defect is not found.

Example 3

The method comprises the following steps: single-piece pre-preparation process

The left spoke plate 2 and the right spoke plate 5 of the blank to be welded are made of powder high-temperature alloy in a forging state, and are shown in FIG. 2; carrying out rough machining by adopting turning; processing the surface to be welded 7 and the reference surface 8 by grinding to ensure that the planeness and the parallelism of the reference surface 8 and the surface to be welded 7 are less than or equal to 0.03 mm; finishing the surface 7 to be welded by adopting precision grinding to ensure that the surface roughness of the surface 7 to be welded is less than or equal to 0.4 mu m, and the surface 7 to be welded has no burn, ablation or other foreign matters;

step two: cleaning of

Degreasing by using absorbent cotton or white cotton cloth, then putting the surfaces 7 to be welded of the two parts to be welded upwards into an ultrasonic cleaning machine for cleaning, wherein a cleaning solvent is deionized water, distilled water, a water-based cleaning agent or alcohol, and no water stain residue exists on the surfaces to be welded after cleaning;

step three: combination of

Aligning and fitting two workpieces to be welded, positioning by using a positioning pin, and checking that the gap between the two surfaces to be welded is less than or equal to 0.02 mm;

step four: into the furnace

Placing a titanium-zirconium-molybdenum alloy die 9 on a diffusion connection equipment platform 10, sequentially placing a component to be welded and a titanium-zirconium-molybdenum alloy upper die 12 on the titanium-zirconium-molybdenum alloy die, then arranging a graphite limiting column 11 around the component to be welded, enabling the graphite limiting column 11 to be 0.08 +/-0.03 mm lower than the upper surface of the titanium-zirconium-molybdenum alloy upper die 12, and enabling an equipment pressing plate 13 to descend to tightly press the titanium-zirconium-molybdenum alloy upper die 12, as shown in figure 3; closing the furnace door and vacuumizing until the vacuum pressure in the furnace is less than 1 x 10 < -4 > mbar and below;

step five: diffusion bonded pre-solder joint

Setting the diffusion bonding pressure to be 15MPa, heating to 800 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 90 min; then heating to 980 ℃ at a heating rate of not more than 5 ℃/min, adjusting the diffusion bonding pressure to 1.5Pa, then heating to 1065 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 180 min; then adjusting the diffusion bonding pressure to be not more than 0.5MPa, keeping the vacuum state, cooling to be below 80 ℃ along with the furnace, and discharging;

step six: vacuum solution treatment

Heating to 800 ℃ at a heating rate of not more than 15 ℃/min, preserving heat for 120min, heating to 1145 +/-10 ℃ at a heating rate of not more than 15 ℃/min, and preserving heat for 210 min; after the heat preservation is finished, filling 5.0bar of high-purity argon, and starting a fan to quickly cool the weldment to below 400 ℃; then, the fan and the argon filling system are closed, and the weldment is cooled to be below 80 ℃ along with the furnace and is discharged from the furnace;

step seven: aging treatment

Adopting a two-stage aging vacuum heat treatment system of 815 +/-10 ℃, preserving heat for 480min, cooling the furnace to below 80 ℃, and discharging; keeping the temperature at 760 +/-10 ℃ for 960min, cooling the furnace to below 80 ℃, and discharging;

step eight: metallographic sectioning test

Sampling in the allowance area, and carrying out joint metallographic examination, wherein the defects of an original diffusion connection interface and a microscopic hole are not found;

step nine: removing allowance by lathing

Turning the allowance outside the rim, radially removing the allowance of 5mm, and finely turning the reference surface of the left spoke plate to ensure that the roughness of the reference surface is less than or equal to 1.6 mu m;

step ten: ultrasonic testing

And (3) detecting from the reference surface of the left spoke plate disc by adopting water immersion ultrasonic waves, and detecting that the standard exceeding defect is not found.

Prior Art-comparative example 1

The method comprises the following steps: single-piece pre-preparation process

The blank of the part to be welded is solid solution powder high-temperature alloy; the turning and grinding precision grinding processing is adopted for processing, the flatness of the surfaces to be welded of the two parts to be welded and the corresponding reference surfaces is less than or equal to 0.03mm, the parallelism between any reference surface and the surface to be welded is less than or equal to 0.03mm, and the surface roughness of the surface to be welded is less than or equal to 0.4 mu m;

step two: cleaning of

Degreasing by using absorbent cotton or white cotton cloth, then putting the surfaces to be welded of the two parts to be welded upwards into an ultrasonic cleaning machine for cleaning, wherein a cleaning solvent is deionized water, distilled water, a water-based cleaning agent or alcohol, and no water stain residue exists on the surfaces to be welded after cleaning;

step three: combination of

Aligning and fitting two workpieces to be welded, positioning by using a positioning pin, and checking that the gap between the two surfaces to be welded is less than or equal to 0.02 mm;

step four: into the furnace

Placing a titanium-zirconium-molybdenum alloy mould on a diffusion connection equipment platform, sequentially placing a component to be welded and a titanium-zirconium-molybdenum alloy upper mould on the titanium-zirconium-molybdenum alloy mould, and then arranging a graphite limiting column around the component to be welded, so that the graphite limiting column is 0.08 +/-0.03 mm lower than the upper surface of the titanium-zirconium-molybdenum alloy upper mould, and a device pressure plate is lowered to tightly press the titanium-zirconium-molybdenum alloy upper mould; closing the furnace door and vacuumizing until the vacuum pressure in the furnace is less than 1 x 10 < -4 > mbar and below;

step five: pre-join

Vacuumizing until the vacuum pressure in the furnace is less than 1 x 10 < -4 > mbar, setting the welding pressure to be 2.0MPa, heating to 800 +/-10 ℃ at the heating rate of not more than 120 ℃/h, and keeping the temperature for 90 min; heating to 1050 +/-10 ℃ at a heating rate of not more than 120 ℃/h, adjusting the welding pressure to 7.0MPa, and keeping the temperature for 150 min;

step six: formal connection

Adjusting the welding pressure to 2.0MPa, continuously heating to 1160 +/-10 ℃ at a heating rate of not more than 120 ℃/h, adjusting the welding pressure to 5.0MPa, and keeping the temperature for 130 min; after the heat preservation is finished, adjusting the welding pressure to 2.0MPa, filling 2.0bar of high-purity argon, starting a fan to rapidly cool to below 50 ℃ and discharging;

step seven: aging treatment

Performing secondary aging vacuum heat treatment, wherein the heat treatment system is 815 +/-10 ℃, preserving heat for 480min, air cooling to below 80 ℃, and discharging; keeping the temperature for 960min at 760 +/-10 ℃, air-cooling to below 80 ℃, and discharging;

step eight: metallographic sectioning test

Sampling in the allowance area, and carrying out joint metallographic examination, wherein the defects of an original diffusion connection interface and a microscopic hole are not found;

step nine: removing allowance by lathing

Turning the allowance outside the rim, radially removing the allowance of 5mm, and finely turning the reference surface of the left spoke plate to ensure that the roughness of the reference surface is less than or equal to 1.6 mu m;

step ten: ultrasonic testing

And (3) detecting from the reference surface of the left spoke plate disc by adopting water immersion ultrasonic waves, and detecting that the standard exceeding defect is not found.

And (3) performing high-temperature tensile test at 700 ℃ and low-cycle fatigue test at 700 ℃ on the allowance zone joints and the furnace-associated base body in the eighth step in the examples 1-3 and the comparative example 1, calculating an average value, and comparing the average value with a material standard value, wherein the test results are as follows:

it can be seen that the 700 ℃ high-temperature tensile and 700 ℃ low-cycle fatigue test data of the diffusion bonding joint and the base material obtained in the embodiment of the invention exceed the material standard values and are higher than the test results of the diffusion bonding joint and the base material obtained in the comparative example 1, which shows that the implementation methods of diffusion bonding pre-welding, post-welding vacuum solution treatment and vacuum aging treatment provided by the invention avoid the performance damage of diffusion bonding high-temperature and long-term thermal cycling to the material in the traditional thermal process route, and realize the function and performance cooperative manufacturing of the double-radial-plate turbine disk.

Claims (1)

1. A method for improving the diffusion bonding performance of a powder superalloy double-spoke plate turbine disc is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: single-piece pre-preparation process

The blank of the workpiece to be welded is a forged powder high-temperature alloy, and rough machining is carried out by adopting turning; processing the surfaces to be welded and the reference surface by grinding; the planeness and the parallelism of the reference surface and the surface to be welded are less than or equal to 0.03 mm; the final processing of the surface to be welded is carried out by adopting precision grinding, so that the surface roughness of the surface to be welded is less than or equal to 0.4 mu m, and the surface to be welded has no burn, ablation or other foreign matters;

step two: cleaning of

Degreasing by using absorbent cotton or white cotton cloth, then putting the to-be-welded surface of the to-be-welded part upwards into an ultrasonic cleaning machine for cleaning, wherein a cleaning solvent is any one of deionized water, distilled water, a water-based cleaning agent or alcohol, and no water stain residue exists on the to-be-welded surface after cleaning;

step three: combination of

Aligning and fitting two workpieces to be welded, positioning by using a positioning pin, and checking that the gap between the two surfaces to be welded is less than or equal to 0.02 mm;

step four: into the furnace

Placing a titanium-zirconium-molybdenum alloy mould on a diffusion connection equipment platform, sequentially placing a component to be welded and a titanium-zirconium-molybdenum alloy upper mould on the titanium-zirconium-molybdenum alloy mould, and then arranging a graphite limiting column around the component to be welded, so that the graphite limiting column is 0.08 +/-0.03 mm lower than the upper surface of the titanium-zirconium-molybdenum alloy upper mould, and a device pressure plate is lowered to tightly press the titanium-zirconium-molybdenum alloy upper mould; closing the furnace door and vacuumizing until the vacuum pressure in the furnace is less than 1 x 10^-4mbar and below;

step five: diffusion bonded pre-solder joint

Setting the diffusion bonding pressure to be 10-20 MPa, heating to 800 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 60-120 min; then heating to 980 ℃ at a heating rate of not more than 5 ℃/min, adjusting the diffusion bonding pressure to 1 MPa-2 MPa, then heating to 1030 +/-10-1100 +/-10 ℃ at a heating rate of not more than 5 ℃/min, and keeping the temperature for 120 min-240 min; then adjusting the diffusion bonding pressure to be not more than 0.5MPa, keeping the vacuum state, cooling to be below 80 ℃ along with the furnace, and discharging;

step six: vacuum solution treatment

Heating to 800 ℃ at a heating rate of not more than 15 ℃/min, preserving heat for 60-120 min, then heating to 1130 +/-10-1160 +/-10 ℃ at a heating rate of not more than 15 ℃/min, and preserving heat for 120-300 min; after the heat preservation is finished, filling 4-6 bar of high-purity argon, starting a fan to quickly cool the weldment to below 400 ℃, then closing the fan and an argon filling system, and cooling the weldment to below 80 ℃ along with the furnace and discharging;

step seven: aging treatment

Adopting secondary aging vacuum heat treatment, wherein the heat treatment system is 815 +/-10-845 +/-10 ℃, keeping the temperature for 240-480 min, cooling the furnace to below 80 ℃, and discharging the furnace; keeping the temperature at 760 +/-10 ℃ for 480-960 min, cooling the furnace to below 80 ℃, and discharging the furnace;

through secondary aging treatment, the precipitation and growth of gamma' phase are further promoted, so that the comprehensive performance of a weldment joint and a base material is improved;

step eight: metallographic sectioning test

Sampling in the allowance area, and carrying out joint metallographic examination, wherein the defects of an original diffusion connection interface and a microscopic hole are not found;

step nine: removing allowance by lathing

Turning the allowance outside the rim, radially removing the allowance of 5mm, and finely turning the reference surface of the left spoke plate to ensure that the roughness of the reference surface is less than or equal to 1.6 mu m;

step ten: ultrasonic testing

And (3) detecting from the reference surface of the left spoke plate disc by adopting water immersion ultrasonic waves, and detecting that the standard exceeding defect is not found.

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