A method for local repair of isothermal forging die for K403 cast high temperature alloy

Abstract

The present invention belongs to the technical field of high temperature alloy mold repair, and relates to a method for locally repairing a K403 casting high temperature alloy isothermal forging mold. By combining the emerging 3D printing and PVD technologies to repair the key parts of the K403 casting high temperature alloy isothermal forging mold lock, the durability and life of the mold for manufacturing titanium alloy isothermal forging blades at the working temperature of 950℃ to 1000℃ can be improved, which greatly reduces the mold manufacturing cost and improves production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature alloy mold repairing, and relates to a method for locally repairing a K403 casting high-temperature alloy isothermal forging mold. Background Art

[0002] The mold material for isothermal forging titanium alloy forgings is generally K403 cast high-temperature alloy. This alloy is comprehensively strengthened with multiple metal elements and has high high-temperature strength. The endurance strength at 1000℃ and 100h can reach 150MPa. The alloy contains less CO and is relatively cheap, but has low medium-temperature plasticity and poor heat corrosion resistance. During use, the K403 alloy isothermal forging mold needs to undergo multiple temperature cycles such as heating and cooling, which can easily cause local cracks. K403 is generally used as the mold material for producing titanium alloy isothermal forging blades. The working temperature of the mold is about 940℃. During the forging process, the mold lock buckle bears a lateral force of about 150MPa, and the working conditions are very harsh. The key part of the mold lock buckle is prone to wear under high temperature (950℃~1000℃) and high pressure (150MPa), which leads to an increase in the lock buckle gap and affects the final qualified rate of the isothermal forged blades. The welding performance of worn parts using traditional surfacing methods is poor. At the same time, the consistency and stability of manual welding processes are poor. Welding cracks and heat-affected zones are prone to occur during the welding process. In particular, the technical risks are greater after repairing the load-bearing parts of the blade with mold locks. Summary of the invention

[0003] Purpose of the invention: To provide a method for locally repairing an isothermal forging die for K403 cast high-temperature alloy.

[0004] Technical solution:

[0005] A method for locally repairing a K403 cast high-temperature alloy isothermal forging die, comprising:

[0006] Step 1: K403 is selected to cast a high-temperature alloy ingot, and the ingot is annealed at 500-600° C. for 8-12 hours to fully eliminate the residual internal stress of the ingot. The annealed rod is peeled, the shrinkage cavity area is cut off, and the end surface is rounded to R5-R10 to make a master alloy consumable electrode rod;

[0007] Step 2: placing a K403 master alloy consumable electrode rod into a gas atomization chamber to obtain a powder with a particle size of 50 to 100 μm;

[0008] Step 3: Polish the worn parts of the mold lock to Ra1.6;

[0009] Step 4: Use 3D printing laser cladding process to repair the worn part of the mold lock. The working band parameters are set to 800-1200nm, the spot diameter is set to 0.4-1.2mm, a laser power device with a laser power of 5-10kW is selected, and the automatic zoom mode is set to print the prepared powder layer onto the surface of the mold lock.

[0010] Step 5: subject the mold after 3D printing and powder coating to stress relief annealing at 300-500°C for 6-12 hours;

[0011] Step 6: sandblast the annealed mold to remove foreign matter from the mold surface;

[0012] Step 7: Place the sandblasted mold into a digital ultrasonic cleaning box for ultrasonic cleaning for 3 to 5 hours, the bath liquid heating temperature is 30 to 100° C., the ultrasonic frequency is set to 30 to 80 kHz, and the cleaning time is 2 to 5 hours;

[0013] In step 8, a CHA-600 electron beam evaporation table is used to send the cleaned mold into the magnetic spray film forming chamber, the vacuum degree is set to below 1.3×10-4Pa, the sputtering speed is set to 7000~10000A / min, the mold preheating temperature is 100~200℃, the target-substrate distance is set to 100~200px, the sputtering time is 20~60min, the vacuum degree is 0.1~1.5Pa, the sputtering angle is set to 3~10°, and a high-temperature resistant TiAlN target is used for coating sputtering on the mold repair part.

[0014] Further, step 1 specifically includes: selecting 8 to 10 K403 casting high-temperature alloy ingots of standard specifications.

[0015] Furthermore, it also includes:

[0016] Step 9: Place the mold after 3D printing repair and PVD sputtering coating into a mold heating furnace for heating at a temperature of 950 to 1000° C. for 15 to 24 hours;

[0017] Step 10: Use the heated mold to isothermally forge the titanium alloy blade to verify the mold repair performance.

[0018] Furthermore, the thickness of the TiAlN coating is less than 0.3 mm.

[0019] Furthermore, the thickness of the 3D printed repair layer is 2 mm.

[0020] Furthermore, step 2 specifically includes: selecting PREP-24000 powder making equipment, setting the atomization chamber pressure to 100-160KPa, setting the equipment power to 150-200KW, setting the electrode rod speed to 10000-25000r / min, setting the working current intensity to 1000-2500A, setting the distance between the plasma gun and the electrode rod to 30-100mm, and introducing inert protective gas.

[0021] Furthermore, step 5 specifically includes: placing in a box-type annealing furnace for annealing.

[0022] Furthermore, the ingot is made by centrifugal casting.

[0023] Beneficial effects:

[0024] For the K403 cast high-temperature alloy isothermal forging mold for matching titanium alloy isothermal forging blades, the key part of the lock will suffer from wear, oxidation and corrosion problems under high temperature and high pressure conditions for a long time. It is difficult to guarantee the service life and stability of the mold using traditional welding technology. At the same time, the manufacturing cost of a single set of molds is high and the production cycle is long, making it difficult to effectively guarantee the production progress goals.

[0025] The present invention combines the emerging 3D printing and PVD technologies to repair the key parts of the K403 casting high-temperature alloy isothermal forging die lock, which can achieve the goal of improving the durability and life of the die for manufacturing titanium alloy isothermal forging blades under working temperature conditions of 950℃~1000℃, greatly reduce the die manufacturing cost, improve production efficiency, and provide a new technical idea for the rapid repair of isothermal forging dies used under high temperature and high pressure conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the principle of the method for locally repairing the isothermal forging die of K403 cast high-temperature alloy according to the present invention;

[0027] Figure 2 This is the assembly drawing of the isothermal forging die for K403 cast high-temperature alloy.

[0028] Among them, 1 is an upper mold, 2 is a lower mold, and 3 is a mold lock. DETAILED DESCRIPTION

[0029] 3D printing technology is an emerging rapid manufacturing additive processing technology. Because of its fast and convenient processing technology, it can be used for customized mold repair under special working conditions. PVD is an emerging technology in the field of material surface treatment technology. Using PVD technology to coat the key parts of the mold with a high-temperature resistant coating can further increase the mold's high-temperature anti-corrosion and anti-oxidation service life.

[0030] This application uses 3D printing and PVD technologies to repair the key locking parts of the K403 casting high-temperature alloy isothermal forging die, solves the problem of mold stability and durability under high temperature and high pressure conditions after local repair of the K403 casting alloy isothermal forging die lock, and achieves the goal of reducing costs and increasing efficiency in mold manufacturing for isothermal forging titanium alloy blades.

[0031] The present invention particularly proposes a method for locally repairing a K403 casting high-temperature alloy isothermal forging die, which can achieve the goal of improving the die durability and life of the key parts of the K403 casting high-temperature alloy isothermal forging die for manufacturing titanium alloy isothermal forging blades under working temperature conditions of 950°C to 1000°C.

[0032] A manufacturing method for locally repairing the isothermal forging die lock of K403 cast high-temperature alloy based on 3D printing and PVD combined technology is carried out in the following steps: blanking - powder making - die polishing - die 3D printing - stress relief annealing - sand blowing - ultrasonic cleaning - PVD deposition of high-temperature wear-resistant coating - isothermal forging test.

[0033] The specific steps include:

[0034] Step 1: Centrifugal casting 8 to 10 K403 high-temperature alloy ingots of the same specification are cast, and the ingots are annealed at 500 to 600°C for 8 to 12 hours to fully eliminate the residual internal stress of the ingots. The annealed bars are peeled, the shrinkage area is cut off, and the end faces are rounded to R5 to R10 to make master alloy consumable electrode rods;

[0035] Step 2: Use PREP-24000 powder making equipment, put the K403 master alloy consumable electrode rod into the gas atomization chamber, set the atomization chamber pressure to 100-160KPa, set the equipment power to 150-200KW, set the electrode rod speed to 10000-25000r / min, set the working current intensity to 1000-2500A, set the distance between the plasma gun and the electrode rod to 30-100mm, and introduce inert protective gas. By comprehensively setting the above reasonable parameters, 10-20Kg of powder with a particle size of 50-100um can be obtained, and the powder particle size of 50-100um can effectively ensure that the subsequent 3D printing repair layer will not have cracks and obvious tissue defects;

[0036] Step 3: polishing the worn parts of the mold lock to Ra1.6 to improve the adhesion effect of the subsequent 3D printed repair layer on the surface of the mold lock 3;

[0037] Step 4: Use the laser cladding process in 3D printing technology to repair the worn parts of the mold lock. The working band parameters are set to 800-1200nm, the spot diameter is set to 0.4-1.2mm, and a laser power device with a laser power of 5-10kW is selected. The automatic zoom mode is set to print the prepared powder layer onto the surface of the mold lock. The thickness of the repair layer h1≤2mm. The thickness of the repair layer should not be too thick or too thin. Too thick increases the difficulty of 3D printing technology, and too thin cannot achieve the bonding surface strength and life. By setting a reasonable thickness range, the initiation of cracks inside the repair layer can be effectively reduced;

[0038] Step 5: Due to the residual tissue tensile stress, the mold after 3D printing is placed in a box-type annealing furnace for stress relief annealing at 300-500°C for 6-12 hours to reduce the internal stress of the repair layer. This can effectively reduce the internal stress and thus improve the bonding strength of the repair layer.

[0039] Step 6: sandblast the annealed mold to remove foreign matter from the mold surface;

[0040] Step 7: Place the sandblasted mold into a digital ultrasonic cleaning box for ultrasonic cleaning for 3 to 5 hours, the bath liquid heating temperature is 30 to 100° C., the ultrasonic frequency is set to 30 to 80 kHz, and the cleaning time is 2 to 5 hours;

[0041] Step 8: Use CHA-600 electron beam evaporation table, send the cleaned mold into the magnetic spray film forming chamber, set the vacuum degree to below 1.3×10-4Pa, set the sputtering speed to 7000-10000A / min, set the mold preheating temperature to 100-200℃, set the target-substrate distance to 100-200px, the sputtering time to 20-60min, the vacuum degree to 0.1-1.5Pa, and the sputtering angle to 3-10°. Use high-temperature resistant TiAlN target material for coating sputtering on the mold repair part, and the coating thickness is ≤0.3mm, because the TiAlN coating can withstand high temperature to maintain the stability of organizational performance, and can also be covered on the mold lock surface to isolate the corrosion effect of external air and acidic substances, and finally improve the wear resistance, corrosion resistance and oxidation resistance of the repaired part;

[0042] Step 9: Place the mold after 3D printing repair and PVD sputtering coating into a mold heating furnace for heating at a temperature of 950 to 1000° C. for 15 to 24 hours;

[0043] Step 10: Use the heated mold to assemble the upper mold 1 and the lower mold 2 and apply a pressure of 2000 tons to the upper mold. Set the upper mold speed to 0.1-0.6 mm / s, perform isothermal forging on the titanium alloy blade, and verify the working life of the repair layer of the mold lock 3 under the condition of withstanding a lateral force of 200 tons. This can improve the wear resistance, oxidation resistance and corrosion resistance of the blade molds for mass production.

[0044] The present invention is further described in detail below through specific embodiments.

[0045] The isothermal forging blade die of the present invention is as follows: Figure 1 As shown, the material is K403 cast high temperature alloy, length 700mm, width 480mm, height 260mm, and the net weight of the mold is 700Kg. The key parts of the mold that need to be repaired are as follows Figure 2 3 in the figure, the lock is 150mm long, 90mm wide and 70mm high. The schematic diagram of the repair principle of the lock based on 3D printing and PVD technology is as follows Figure 1 shown.

[0046] The manufacturing steps are detailed as follows:

[0047] 1. Made by centrifugal casting Ten K403 high-temperature alloy ingots were cast and annealed at 550℃ for 12 hours to fully eliminate the residual internal stress of the ingots. The annealed bars were peeled, the shrinkage area was cut off, and the end surface was rounded to R10 to make the master alloy consumable electrode rods.

[0048] 2. Select PREP-24000 powder making equipment, put K403 master alloy consumable electrode rod into the gas atomization chamber, set the atomization chamber pressure to 150KPa, the equipment power to 160KW, the electrode rod speed to 15000r / min, the working current intensity to 2000A, the distance between the plasma gun and the electrode rod to 80mm, introduce inert protective gas, and obtain about 15Kg of powder with a particle size of 50-100um;

[0049] 3. Polish the worn parts of the mold lock to Ra1.6;

[0050] 4. Use the laser cladding process in 3D printing technology to repair the worn parts of the mold lock. Set the working band parameter to 1000nm, the spot diameter to 0.8mm, select a laser power of 10kW, set the automatic zoom mode, and print the prepared powder layer onto the surface of the mold lock.

[0051] 5. Place the mold after 3D printing and powder coating into a box-type annealing furnace for stress relief annealing at 300-500℃ for 10 hours;

[0052] 6. Sandblast the annealed mold to remove impurities and foreign matter on the mold surface;

[0053] 7. Place the sandblasted mold into a digital ultrasonic cleaning box for ultrasonic cleaning for 3.5 hours. The bath heating temperature is 50°C, the ultrasonic frequency is set to 500kHz, and the cleaning time is about 3.5 hours.

[0054] 8. Use CHA-600 electron beam evaporation table to send the cleaned mold into the magnetic spray film forming chamber, set the vacuum degree to below 1.3×10-4Pa, the sputtering speed to 9000A / min, the mold preheating temperature to 200℃, the target-substrate distance to 150px, the sputtering time to 40min, the vacuum degree to 0.8Pa, the sputtering angle to 5°, and use high temperature resistant TiAlN target material for coating sputtering on the mold repair part;

[0055] 9. Place the mold after 3D printing repair and PVD sputtering coating into the mold heating furnace for heating at a temperature of 950°C for 20 hours;

[0056] 10. Use the heated mold to isothermally forge the titanium alloy blades.

[0057] By using 3D printing and PVD technologies to repair the key parts of the lock of the K403 cast high-temperature alloy isothermal forging die, the durability and life of the die for manufacturing titanium alloy isothermal forging blades under the working temperature conditions of 950℃~1000℃ can be increased by 1.5 times, which greatly reduces the mold manufacturing cost and improves production efficiency, providing a new technical idea for the rapid repair of isothermal forging dies used under high temperature and high pressure conditions.

Claims

1. A method for locally repairing a K403 cast high-temperature alloy isothermal forging die, characterized in that: include: Step 1: Select K403 to cast a high-temperature alloy ingot, anneal the ingot at 500-600°C for 8-12 hours to fully eliminate the residual internal stress of the ingot, peel the annealed bar, cut off the shrinkage area and round the end surface to R5-R10 to make a master alloy consumable electrode rod; Step 2: Place the K403 master alloy consumable electrode rod into the gas atomization chamber to obtain a powder with a particle size of 50 to 100 um; Step 3: Polish the worn parts of the mold lock to Ra1.6; Step 4: Use the 3D printing laser cladding process to repair the worn parts of the mold lock. The working band parameters are set to 800-1200nm, the spot diameter is set to 0.4-1.2mm, and a laser power device with a laser power of 5-10kW is selected. The automatic zoom mode is set to print the prepared powder layer onto the surface of the mold lock. Step 5: Perform stress relief annealing at 300-500°C on the mold after 3D printing and powder coating for 6-12 hours; Step 6: Sandblast the annealed mold to remove impurities and foreign matter on the mold surface; Step 7: Place the sandblasted mold into a digital ultrasonic cleaning box for ultrasonic cleaning for 3 to 5 hours. The bath liquid heating temperature is 30 to 100°C, the ultrasonic frequency is set to 30 to 80kHz, and the cleaning time is 2 to 5 hours. Step 8: Select CHA-600 electron beam evaporation table, send the cleaned mold into the magnetic spray film forming chamber, set the vacuum degree to below 1.3×10-4Pa, set the sputtering speed to 7000~10000A / min, the mold preheating temperature to 100~200℃, set the target-substrate distance to 100~200px, the sputtering time to 20~60min, the vacuum degree to 0.1~1.5Pa, the sputtering angle to 3~10°, and use high temperature resistant TiAlN target for coating sputtering on the mold repair part.

2. The method according to claim 1, characterized in that Step 1 specifically includes: Select 8 to 10 K403 casting high-temperature alloy ingots of standard specifications.

3. The method according to claim 1, characterized in that Also includes: Step 9: Place the mold after 3D printing repair and PVD sputtering coating into a mold heating furnace for heating at a temperature of 950 to 1000°C for 15 to 24 hours; Step 10: Use the heated die to isothermally forge the titanium alloy blade to verify the die repair performance.

4. The method according to claim 1, characterized in that: The thickness of the TiAlN coating is less than 0.3 mm.

5. The method according to claim 1, characterized in that The thickness of the 3D printed repair layer is 2 mm.

6. The method according to claim 1, characterized in that Step 2 specifically includes: selecting PREP-24000 powder making equipment, setting the atomization chamber pressure to 100-160KPa, setting the equipment power to 150-200KW, setting the electrode rod speed to 10000-25000r / min, setting the working current intensity to 1000-2500A, setting the distance between the plasma gun and the electrode rod to 30-100mm, and introducing inert protective gas.

7. The method according to claim 1, characterized in that Step 5 specifically includes: placing in a box-type annealing furnace for annealing.

8. The method according to claim 2, characterized in that: The ingot is made by centrifugal casting.

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