阅读说明：本技术 等轴晶材料涡轮导向叶片铸造缺陷修复材料及修复方法 (Casting defect repair material and repair method for isometric crystal material turbine guide blade ) 是由 秦仁耀 梁家誉 张国会 陈冰清 赵梓均 于 2020-10-30 设计创作，主要内容包括：本发明涉及航空发动机热端关键部件维修技术领域,提供了一种等轴晶材料涡轮导向叶片铸造缺陷修复材料及修复方法,修复用填充材料为粒径Φ53～Φ150μm的高温合金粉末,其组分及质量百分比：C：0.12～0.18％,Cr：15.5～16.5％,Co：12.5～13.5％,W：3.5～4.5％,Mo：3.5～4.5％,Nb：0.6～1.0％,Al：2.0～2.5％,Ti：3.5～4.0％,Zr：0.03～0.08％,B：0.006～0.015％,Ta：＜0.2％,Si：＜0.2％,Mn：＜0.12％,Fe：＜0.35％,P：≤0.01％,S：≤0.01％,O：≤0.010％,N：≤0.008％,Ni为余量；所述修复方法在修复前对待修复叶片进行固溶热处理：后采用激光直接沉积方法进行修复,并恢复尺寸；本发明的修复方法和修复材料实现了高Al、Ti含量等轴晶高温合金涡轮导向叶片修复效率、修复接头质量和性能的大幅提高,对促进发动机的研制和应用具有重要意义。(The invention relates to the technical field of maintenance of key components at the hot end of an aeroengine, and provides a repair material and a repair method for casting defects of a turbine guide blade made of an isometric crystal material, wherein a filling material for repair is high-temperature alloy powder with the particle size of phi 53-phi 150 mu m, and the repair material comprises the following components in percentage by mass: c: 0.12-0.18%, Cr: 15.5-16.5%, Co: 12.5-13.5%, W: 3.5-4.5%, Mo: 3.5-4.5%, Nb: 0.6-1.0%, Al: 2.0-2.5%, Ti: 3.5-4.0%, Zr: 0.03-0.08%, B: 0.006-0.015%, Ta: < 0.2%, Si: < 0.2%, Mn: < 0.12%, Fe: < 0.35%, P: less than or equal to 0.01 percent, S: less than or equal to 0.01 percent, O: less than or equal to 0.010 percent, N: less than or equal to 0.008 percent and the balance of Ni; the repairing method comprises the following steps of carrying out solution heat treatment on a blade to be repaired before repairing: then adopting a laser direct deposition method to repair and restore the size; the repair method and the repair material of the invention realize the great improvement of the repair efficiency, the repair joint quality and the performance of the high Al and Ti content equiaxial crystal superalloy turbine guide blade, and have important significance for promoting the development and the application of an engine.)

1. The casting defect repair material for the isometric crystal turbine guide blade is characterized in that: the repair material is high-temperature alloy powder for laser repair, and comprises the following components in percentage by mass: c: 0.12-0.18%, Cr: 15.5-16.5%, Co: 12.5-13.5%, W: 3.5-4.5%, Mo: 3.5-4.5%, Nb: 0.6-1.0%, Al: 2.0-2.5%, Ti: 3.5-4.0%, Zr: 0.03-0.08%, B: 0.006-0.015%, Ta: < 0.2%, Si: < 0.2%, Mn: < 0.12%, Fe: < 0.35%, P: less than or equal to 0.01 percent, S: less than or equal to 0.01 percent, O: less than or equal to 0.010 percent, N: less than or equal to 0.008 percent, Ni: and (4) the balance.

2. The cast defect repair material for the turbine guide blade made of the isometric crystal material as claimed in claim 1, wherein: the repair material comprises the following components in percentage by mass: c: 0.12-0.15%, Cr: 15.8-16.5%, Co: 12.8-13.5%, W: 3.8-4.2%, Mo: 3.8-4.2%, Nb: 0.6-1.0%, Al: 2.0-2.4%, Ti: 3.5-3.7%, Al + Ti: less than or equal to 6.0 percent, Zr: 0.035-0.05%, B: 0.010-0.015%, Ta: < 0.2%, Si: < 0.2%, Mn: < 0.12%, Fe: < 0.35%, P: less than or equal to 0.01 percent, S: less than or equal to 0.01 percent, O: less than or equal to 0.008 percent, N: less than or equal to 0.005 percent, Ni: and (4) the balance.

3. The cast defect repair material for the turbine guide blade made of the isometric crystal material as claimed in claim 1, wherein: the repair material comprises the following components in percentage by mass: c: 0.12%, Cr: 16.3%, Co: 13.3%, W: 4.0%, Mo: 3.9%, Nb: 0.9%, Al: 2.1%, Ti: 3.5%, Zr: 0.045%, B: 0.014%, Ta: 0.11%, Si: 0.10%, Mn: 0.10%, Fe: 0.05%, P: 0.006%, S: 0.003%, O: 0.006%, N: 0.002%, Ni: and (4) the balance.

4. The method for repairing the casting defect of the turbine guide blade made of the isometric crystal material by using the repairing material of claim 1 is characterized in that: the method for repairing the casting defects of the isometric crystal superalloy turbine guide vane by adopting a laser direct deposition process comprises the following steps:

step one, solution heat treatment before repair: putting the isometric crystal superalloy turbine guide vane with casting defects into a vacuum heat treatment furnace for solution heat treatment with homogenized components and structures, wherein the heat treatment process requirements are as follows: at vacuum pressure lower than 3X 10^-2Under the condition of Pa, heating to 1200-1215 ℃ at the speed of 50-80 ℃/min, and preserving heat for 25-30 min; cooling to 1170-1185 ℃ along with the furnace, and preserving heat for 50-60 min; then cooling, cooling to below 500 ℃ along with the furnace, and filling air to cool to room temperature quickly;

secondly, removing the defects before repairing, and polishing the area to be repaired;

step three, laser direct deposition repair: repairing the polished area by adopting a laser direct deposition method, and recovering the size of the casting defect, wherein the repairing process parameters are as follows: the laser power is 450-900W, the laser scanning speed is 500-900 mm/min, the powder feeding speed is 4-9 g/min, the lap joint rate between the tracks is 45-60%, and the coaxial protective gas flow is 10-20L/min.

5. The method for repairing casting defects of the turbine guide blade made of the isometric crystal material as recited in claim 4, wherein the method comprises the following steps: the first step also comprises the step of nondestructive detection of the defects, and the specific operation is as follows:

the turbine guide vane casting is inspected by visual, fluoroscopic and X-ray inspection to determine the location, type, number, size of defects.

6. The method for repairing casting defects of the turbine guide blade made of the isometric crystal material as recited in claim 4, wherein the method comprises the following steps: the second step is specifically operated as follows:

and removing the casting defects by adopting a mechanical polishing mode until the metal luster is exposed, cleaning the polishing area and the peripheral area thereof by adopting acetone or alcohol, and drying by using a blower or a fan.

7. The method for repairing casting defects of the turbine guide blade made of the isometric crystal material as recited in claim 4, wherein the method comprises the following steps: the specific parameters of each repair layer in the laser direct deposition repair process in the third step are as follows:

the laser power of the first repairing layer adjacent to the blade substrate is 450-600W, the laser scanning speed is 500-700 mm/min, the powder feeding speed is 4-6 g/min, the lap joint rate between the tracks is 45-60%, the flow rate of the coaxial protective gas is 10-20L/min, the laser power of the second repairing layer and the repairing layers above is 600-900W, the laser scanning speed is 500-900 mm/min, the powder feeding speed is 5-9 g/min, the lap joint rate between the tracks is 45-60%, and the flow rate of the coaxial protective gas is 10-20L/min.

8. The method for repairing casting defects of the turbine guide blade made of the isometric crystal material as recited in claim 4, wherein the method comprises the following steps: the particle size of the filling material for laser repair in the third step is phi 53-phi 150 mu m.

9. The method for repairing casting defects of the turbine guide blade made of the isometric crystal material as recited in claim 4, wherein the method comprises the following steps: the method for repairing the casting defects of the turbine guide blade made of the isometric crystal material further comprises the steps of performing finish machining on the size of a repair area and performing nondestructive testing on the repair part.

10. The method for repairing casting defects of the turbine guide blade made of the isometric crystal material as recited in claim 9, wherein: the concrete operations of the size fine machining of the repair area and the nondestructive detection of the repair part are as follows:

and (3) finishing the size of the repair area: processing the repair area by adopting a grinding and milling mode to recover the size of the blade;

nondestructive detection of the repaired part: and (3) performing surface and internal quality inspection on the repair area and the surrounding area thereof by adopting a fluorescence flaw detection method and an X-ray method.

Technical Field

The invention relates to the technical field of repair, in particular to a casting defect repair material and a repair method for an isometric crystal material turbine guide blade.

Background

Aiming at the high performance requirement of advanced aeroengines, the application of equiaxed high-temperature alloy with high Al and Ti content in turbine guide vanes of engines is increasingly wide, such as K418B, K447A, K465 and the like. In order to improve the cooling effect of the turbine guide blade of an aero-engine during working, the turbine guide blade at home and abroad generally adopts a multi-connected air-cooled hollow structure, the inner cavity of the turbine guide blade is complex, the blade body wall and the edge plate are thin, the size precision is high, the difficulty of the casting process of the blade is high, and the casting product generally has local defects of shrinkage cavity, shrinkage porosity, cavities, undercasting, inclusion and the like, so that the casting product cannot meet the use requirement, the rejection rate of a new casting product is as high as more than 70%, and the repair is urgently needed.

Because the content of Al and Ti in the isometric crystal high-temperature alloy with high Al and Ti content is as high as 6.2-8.9 wt.%, when a conventional fusion welding method and a base metal filling material are adopted for repairing, thermal cracks are easy to appear on a repaired joint (comprising a repairing area and a base body heat affected area), the repaired joint is frequently repaired for more than 2 times, on one hand, the repairing quality is extremely unstable, and on the other hand, the repairing qualified rate is usually less than 30%. Therefore, efficient and reliable repair techniques and repair materials are urgently needed.

Compared with the conventional fusion welding method, the heat input amount of the laser direct deposition process is small, so that a heat affected zone and local residual stress formed in the repair process are smaller, the heat crack tendency is reduced, and the repair method is suitable for repairing the casting defects of the isometric crystal superalloy turbine guide vane with high Al and Ti contents.

At present, the material for welding and repairing the isometric crystal superalloy with high Al and Ti content such as K447A is generally a nickel-based alloy with low Al and Ti content (the content of Al + Ti is less than or equal to 1.5 wt.%). The low Al and Ti contents make the repair materialGamma prime strengthening with excellent formability (i.e. weldability), but also results in a repair zone that is difficult to precipitate age-strengthen₃The Al phase causes the high-temperature strength, the durability and the temperature resistance of the room in the repair area to be obviously reduced. The cast defect repair area of the isometric crystal superalloy turbine guide vane becomes a 'short plate' when a part is in service, and the service life and reliability are seriously influenced, so that the high-temperature performance of the chamber is required to be close to that of a vane substrate and the repair material has good formability.

Disclosure of Invention

The purpose of the invention is: the casting defect repair material and the repair method for the isometric crystal turbine guide blade are provided, the breakthrough of the casting defect repair technology for the isometric crystal high-temperature alloy turbine guide blade with Al and Ti contents is realized, and the repair quality and the joint performance are improved.

In order to solve the technical problem, the technical scheme of the invention is as follows:

on the one hand, the casting defect repair material for the turbine guide blade made of the isometric crystal material is provided, and the repair material is high-temperature alloy powder for laser repair, and comprises the following components in percentage by mass: c: 0.12-0.18%, Cr: 15.5-16.5%, Co: 12.5-13.5%, W: 3.5-4.5%, Mo: 3.5-4.5%, Nb: 0.6-1.0%, Al: 2.0-2.5%, Ti: 3.5-4.0%, Zr: 0.03-0.08%, B: 0.006-0.015%, Ta: < 0.2%, Si: < 0.2%, Mn: < 0.12%, Fe: < 0.35%, P: less than or equal to 0.01 percent, S: less than or equal to 0.01 percent, O: less than or equal to 0.010 percent, N: less than or equal to 0.008 percent, Ni: and (4) the balance.

Further, the repair material comprises the following components in percentage by mass: c: 0.12-0.15%, Cr: 15.8-16.5%, Co: 12.8-13.5%, W: 3.8-4.2%, Mo: 3.8-4.2%, Nb: 0.6-1.0%, Al: 2.0-2.4%, Ti: 3.5-3.7%, Al + Ti: less than or equal to 6.0 percent, Zr: 0.035-0.05%, B: 0.010-0.015%, Ta: < 0.2%, Si: < 0.2%, Mn: < 0.12%, Fe: < 0.35%, P: less than or equal to 0.01 percent, S: less than or equal to 0.01 percent, O: less than or equal to 0.008 percent, N: less than or equal to 0.005 percent, Ni: and (4) the balance.

Preferably, the repair material comprises the following components in percentage by mass: c: 0.12%, Cr: 16.3%, Co: 13.3%, W: 4.0%, Mo: 3.9%, Nb: 0.9%, Al: 2.1%, Ti: 3.5%, Zr: 0.045%, B: 0.014%, Ta: 0.11%, Si: 0.10%, Mn: 0.10%, Fe: 0.05%, P: 0.006%, S: 0.003%, O: 0.006%, N: 0.002%, Ni: and (4) the balance.

On the other hand, the method for repairing the casting defects of the turbine guide blade made of the isometric crystal material is provided, the casting defects of the turbine guide blade made of the isometric crystal material are repaired by using the repair material and adopting a laser direct deposition process, and the method comprises the following steps of:

step one, solution heat treatment before repair: putting the isometric crystal superalloy turbine guide vane with casting defects into a vacuum heat treatment furnace for solution heat treatment with homogenized components and structures, wherein the heat treatment process requirements are as follows: at vacuum pressure lower than 3X 10^-2Under the condition of Pa, heating to 1200-1215 ℃ at the speed of 50-80 ℃/min, and preserving heat for 25-30 min; cooling to 1170-1185 ℃ along with the furnace, and preserving heat for 50-60 min; then cooling, cooling to below 500 ℃ along with the furnace, and filling air to cool to room temperature quickly;

secondly, removing the defects before repairing, and polishing the area to be repaired;

step three, laser direct deposition repair: repairing the polished area by adopting a laser direct deposition method, and recovering the size of the casting defect, wherein the repairing process parameters are as follows: the laser power is 450-900W, the laser scanning speed is 500-900 mm/min, the powder feeding speed is 4-9 g/min, the lap joint rate between the tracks is 45-60%, and the coaxial protective gas flow is 10-20L/min.

The first step also comprises the step of carrying out nondestructive detection on the defects.

The method comprises the following specific operations: the turbine guide vane casting is inspected by visual, fluoroscopic and X-ray inspection to determine the location, type, number, size of defects.

The second step is as follows:

and removing the casting defects by adopting a mechanical polishing mode until the metal luster is exposed, cleaning the polishing area and the peripheral area thereof by adopting acetone or alcohol, and drying by using a blower or a fan.

The specific parameters of each repair layer in the laser direct deposition repair process in the third step are as follows:

the laser power of the first repairing layer adjacent to the blade substrate is 450-600W, the laser scanning speed is 500-700 mm/min, the powder feeding speed is 4-6 g/min, the lap joint rate between the tracks is 45-60%, the flow rate of the coaxial protective gas is 10-20L/min, the laser power of the second repairing layer and the repairing layers above is 600-900W, the laser scanning speed is 500-900 mm/min, the powder feeding speed is 5-9 g/min, the lap joint rate between the tracks is 45-60%, and the flow rate of the coaxial protective gas is 10-20L/min.

The particle size of the filling material for laser repair in the third step is phi 53-phi 150 mu m.

The method for repairing the casting defects of the turbine guide blade made of the isometric crystal material further comprises the steps of performing finish machining on the size of a repair area and performing nondestructive testing on the repair part. The method comprises the following specific operations:

and (3) finishing the size of the repair area: processing the repair area by adopting grinding, milling and other modes to recover the size of the blade;

nondestructive detection of the repaired part: and (3) carrying out surface and internal quality inspection on the repair area and the surrounding area thereof by adopting a fluorescent flaw detection and X-ray method, wherein the repair area and the surrounding area thereof are required to have no crack or fusion defect.

The invention has the beneficial effects that:

the repairing material in the technical scheme comprises the following components:

in addition, in order to improve the hot crack sensitivity of the isometric crystal superalloy guide blade during repair and ensure that a repaired joint has good high-temperature performance, the components of the repair material are optimally designed based on the chemical components of the isometric crystal superalloy with high Al and Ti contents such as K447 and K465 and the like and the action of alloy elements in the superalloy, and the design basis is as follows:

(1) chromium: is an important solid solution strengthening element and carbide forming element in the high-temperature alloy, can be dissolved in a gamma phase in a solid mode and can also enter a gamma' phase, so that the solid solution strengthening effect is achieved; simultaneously can form MC, M with carbon element₆C and M₂₃C₆Carbides, which strengthen the grain boundaries, andand the Cr can form oxidation-resistant and corrosion-resistant Cr on the surface of the material₂O₃The protective layer can effectively prevent the outward diffusion of metal elements and the inward diffusion of harmful elements such as O, N, S and the like, plays an important role in improving the heat strength and the corrosion resistance of the alloy, but the excessive Cr content can reduce the solid solution temperature of a gamma' phase and reduce the high-temperature performance. Therefore, the Cr content in the repair powder is controlled to be 15.5-16.5 wt.%.

(2) Cobalt: the alloy has a solid solution strengthening effect in the high-temperature alloy, and most of the alloy is distributed in a solid solution gamma-phase matrix, so that the stacking fault energy of the matrix is reduced, and the high-temperature endurance strength and creep resistance of the alloy are improved; a small part enters into the gamma 'phase to improve the solid solution temperature of the gamma' phase. In addition, increasing the Co content can precipitate gamma' phase, increase the solid solubility of C, reduce carbide precipitation, contribute to reducing the width of a Cr-poor region of a grain boundary, and improve the plasticity and the formability of the alloy. Therefore, the Co content in the repair powder is controlled to be 12.5-13.5 wt.%.

(3) Aluminum and titanium: is a main forming element of a gamma 'phase, the high-temperature performance of the nickel-based high-temperature alloy is mainly determined by the total content of Al and Ti and the ratio of Ti to Al, the solid solution temperature and the volume fraction of the gamma' phase can be obviously improved by increasing the total content of Al and Ti, but the tendency of forming eutectic and hot cracks in the material forming process is rapidly increased along with the increase of the total content of Al and Ti, so that the formability of the material is rapidly deteriorated. Therefore, in order to improve the formability of the repair material, the total amount of Al + Ti in the repair powder is preferably controlled within 6.0%, and simultaneously, the improvement of the Ti content (namely the Ti/Al ratio) can improve the hot corrosion resistance of the alloy, promote the formation of MC type carbide between grain boundaries and dendrites, and inhibit M₂₃C₆Carbide is precipitated, so that the endurance strength of crystal boundaries and crystal grains is improved, and the width of a crystal boundary Cr-poor area is reduced. However, when the ratio of Ti/Al is too high, coarse flakes (Ni) are liable to appear₃Ti) brittle phase. Therefore, the Ti content and the Al content in the repair powder are controlled to be 3.5-3.9 wt.% and 2.0-2.4 wt.%.

(4) Tungsten and molybdenum: the high-temperature alloy can be dissolved in a gamma phase and a gamma 'phase in a solid mode, and has strong solid solution strengthening effect on the gamma and gamma' phases due to the fact that the difference between the atomic radius of the two elements and the atomic radius of Ni is large, the recrystallization temperature can be increased, and the heat strength and the heat stability of the alloy are improved. However, W and Mo are also elements forming the TCP phase, and higher contents tend to form the harmful phase of TCP during the subsequent heat treatment. In addition, W and Mo are prone to volatile oxides, and dense oxide scale is difficult to form, so that high W and Mo contents are unfavorable for oxidation resistance and hot corrosion resistance of the high-temperature alloy. Therefore, the W content of the repair powder is controlled to be 3.8-4.2 wt%, and the Mo content is controlled to be 3.8-4.2 wt%.

(5) Niobium: is a gamma prime phase forming element which can enter the gamma prime phase and replace a part of Al and Ti. The addition of Nb can promote the precipitation of the gamma ' phase and delay the aggregation and growth of the gamma ' phase, so that the high-temperature strength of the alloy can be improved, and the solid solution temperature of the gamma ' phase can be increased. Nb is also a strong carbide forming element, can form stable NbC carbide and has strengthening effect on crystal grains and grain boundaries. However, the formation of TCP phase is promoted by the high Nb content, and Nb is also a strong oxygen-affinity element and has damage to the oxidation resistance of the alloy. Therefore, the Nb content in the repair powder is controlled to be 0.6-1.0 wt.%.

(6) Carbon: is an important crystal boundary and interdendritic strengthening element in the high-temperature alloy. However, C has very low solubility in the gamma phase and does not enter the gamma' phase, so the content of C in the high-temperature alloy is low. C which is partially gathered between the grain boundary and the dendrite not only can be used as a gap element to fill the gaps of the areas, slow down diffusion, reduce the cracking tendency between the grain boundary and the dendrite, improve the endurance strength of the alloy, but also can form MC and M₆C and M₂₃C₆The carbide type improves the room high temperature strength between grain boundary and dendrite, but the coarse and string M is gathered at the grain boundary₂₃C₆Carbide type rather increases the tendency of grain boundaries to crack and reduces their strength. Therefore, the C content in the repair powder is controlled to be 0.12-0.18 wt.%.

(7) Boron and zirconium: B. zr exists mainly in grain boundary and can inhibit M₂₃C₆The aggregation of the carbide retards the initiation of grain boundary cracks, simultaneously reduces the segregation of C at the grain boundary, increases the quantity of the carbide in the grain, and can improve the creep resistance and the endurance life of the alloy. In addition, the existing research shows that the addition of trace B, Zr can obviously improve the alloyThe endurance life of the alloy is prolonged, the creep rate is reduced, the endurance notch sensitivity is obviously improved, the plasticity and the processing performance of the alloy are improved, and the performance optimization effect is more obvious compared with that of Zr and B. However, when the content of B is too high, hard and brittle borides can be formed on grain boundaries, and the boride has a low melting point and is a factor for reducing the endurance quality and plasticity of the alloy. Higher amounts of Zr can form low melting phases in the superalloy, resulting in significant reductions in formability and high temperature strength, long-term strength. Therefore, the B content and the Zr content in the repair powder are controlled to be 0.006-0.015% and 0.03-0.08%, respectively.

Firstly, compared with the conventional fusion welding repair method, when the laser direct deposition method is used for repairing the casting defects of the isometric crystal superalloy turbine guide blade with high Al and Ti contents, the heat input is small, so that the size of a heat affected zone of a matrix is smaller, the tendency of hot cracking is greatly reduced, the influence on the performance of the matrix is greatly reduced, repeated repair is avoided, and the quality and the efficiency of repairing the joint are greatly improved.

Secondly, the solution heat treatment performed before the repair according to the present invention brings the following advantageous effects:

compared with the common repair materials of low-Al and Ti-content high-temperature alloys (such as GH3536, GH3625 and the like) and base material components, the repair material disclosed by the invention contains higher-content gamma' phase forming elements (such as Al, Ti and Nb) and solid solution strengthening elements (such as Cr, Co, W and Mo), and combines trace grain boundary strengthening elements (such as C, B and Zr), so that the repair material has good laser direct deposition formability (namely low hot crack sensitivity), and meanwhile, the repair joint can be ensured to have more excellent high-temperature performance, such as the high-temperature strength and the lasting strength which can reach more than 85% of the performance of a parent material, and the performance of the joint repaired by the conventional fusion welding method and the repair material thereof is far superior to the performance of the joint repaired by the conventional fusion welding method and the repair.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Repair Material composition 1

The filling material for laser repair in this embodiment: the filling material is high-temperature alloy powder with the grain diameter of phi 53-phi 150 mu m, and the chemical components (wt.%) of the powder are as follows: c: 0.16%, Cr: 16.2%, Co: 12.9%, W: 3.8%, Mo: 4.0%, Nb: 0.7%, Al: 2.1%, Ti: 3.6%, Zr: 0.05%, Ta: 0.15%, Si: 0.06%, Mn: 0.10%, Fe: 0.15%, B: 0.011%, P: 0.006%, S: 0.003%, O: 0.005%, N: 0.003%, Ni: and (4) the balance.

Repair Material composition 2

The filling material for laser repair in this embodiment: the filling material is high-temperature alloy powder with the grain diameter of phi 53-phi 150 mu m, and the chemical components (wt.%) of the powder are as follows: c: 0.12%, Cr: 15.8%, Co: 13.3%, W: 4.2%, Mo: 4.0%, Nb: 0.9%, Al: 2.3%, Ti: 3.7%, Zr: 0.04%, Ta: 0.10%, Si: 0.08%, Mn: 0.08%, Fe: 0.20%, B: 0.008%, P: 0.006%, S: 0.002%, O: 0.006%, N: 0.002%, Ni: and (4) the balance.

Repair Material component 3

The filling material for laser repair in this embodiment: the filling material is high-temperature alloy powder with the grain diameter of phi 53-phi 150 mu m, and the chemical components (wt.%) of the powder are as follows: c: 0.14%, Cr: 16.3%, Co: 13.1%, W: 4.0%, Mo: 3.9%, Nb: 0.8%, Al: 2.4%, Ti: 3.5%, Zr: 0.045%, Ta: 0.13%, Si: 0.10%, Mn: 0.05%, Fe: 0.10%, B: 0.012%, P: 0.005%, S: 0.003%, O: 0.005%, N: 0.005%, Ni: and (4) the balance.

Repair Material composition 4

The filling material for laser repair in this embodiment: the filling material is high-temperature alloy powder with the grain diameter of phi 53-phi 150 mu m, and the chemical components (wt.%) of the powder are as follows: c: 0.15%, Cr: 16.5%, Co: 13.0%, W: 3.9%, Mo: 3.8%, Nb: 0.6%, Al: 2.0%, Ti: 3.7%, Zr: 0.05%, Ta: 0.18%, Si: 0.05%, Mn: 0.09%, Fe: 0.16%, B: 0.010%, P: 0.008%, S: 0.006%, O: 0.007%, N: 0.002%, Ni: and (4) the balance.

Repair Material composition 5

The filling material for laser repair in this embodiment: the filling material is high-temperature alloy powder with the grain diameter of phi 53-phi 150 mu m, and the chemical components (wt.%) of the powder are as follows: c: 0.13%, Cr: 16.1%, Co: 12.8%, W: 4.1%, Mo: 4.2%, Nb: 1.0%, Al: 2.2%, Ti: 3.6%, Zr: 0.035%, Ta: 0.12%, Si: 0.08%, Mn: 0.05%, Fe: 0.05%, B: 0.013%, P: 0.005%, S: 0.003%, O: 0.005%, N: 0.003%, Ni: and (4) the balance.

Repair Material composition 6

The filling material for laser repair in this embodiment: the filling material is high-temperature alloy powder with the grain diameter of phi 53-phi 150 mu m, and the chemical components (wt.%) of the powder are as follows: c: 0.12%, Cr: 16.3%, Co: 13.3%, W: 4.0%, Mo: 3.9%, Nb: 0.9%, Al: 2.1%, Ti: 3.5%, Zr: 0.045%, Ta: 0.11%, Si: 0.10%, Mn: 0.10%, Fe: 0.05%, B: 0.014%, P: 0.006%, S: 0.003%, O: 0.006%, N: 0.002%, Ni: and (4) the balance.

The components of the material can achieve the aim of repairing, and the following repairing parameters are adopted: the temperature of solid solution heat treatment before repair is 1200-1215 ℃, the temperature is kept for 25-30 min, the temperature is cooled to 1170-1185 ℃ along with a furnace, the temperature is kept for 50-60 min, then when laser repair is carried out, the laser power of a first repair layer adjacent to a blade substrate is 450-600W, the laser scanning speed is 500-700 mm/min, the powder feeding speed is 4-6 g/min, the lap joint rate between lanes is 45-60%, the flow of coaxial protective gas is 10-20L/min, the laser power of a second repair layer and the repair layers above is 600-900W, the laser scanning speed is 500-900 mm/min, the powder feeding speed is 5-9 g/min, the lap joint rate between lanes is 45-60%, and the flow of coaxial protective gas is 10-20L/min. The average room-temperature tensile strength of the obtained repair metal is not lower than 950MPa, the endurance life of the repair metal is not lower than 50h under the conditions of 980 ℃/160MPa, and the repair metal meets the use requirements of the cast high-temperature alloy guide vanes such as K418B, K447A and K465.

In combination with the repair material component 6, the components of the filling material for laser repair are the repair material component 6: the grain diameter is phi 53-phi 150 mu m, and the specific repair method of the invention is described as follows:

the method adopts Arnold laser direct deposition equipment to repair the casting shrinkage cavity defect of the K447A turbine guide blade shroud, and comprises the following specific steps:

1. nondestructive defect detection: through visual and fluorescent inspection of a turbine guide blade casting, 1 shrinkage cavity defect exists on the upper surface of a guide blade shroud, and the outline size of the outer surface of each shrinkage cavity is about 2.0mm multiplied by 2.5 mm;

2. solution heat treatment before repair: after being soaked and cleaned by acetone or alcohol, the guide vane is put into a cavity of a vacuum heat treatment furnace for solution heat treatment, and the heat treatment process comprises the following steps: at vacuum pressure lower than 3X 10^-2When Pa is needed, heating to 1210 ℃ at the speed of 80 ℃/min, and keeping the temperature for 25 min; cooling to 1175 deg.C with furnace, and maintaining for 55 min; then cooling, cooling to below 500 ℃ along with the furnace, and filling air to cool to room temperature quickly;

3. defect removal before repair: removing casting defects by adopting a handheld grinding gun tool, exposing metallic luster, stopping grinding after displaying no defect through fluorescence detection, wherein the surface outline of a grinding area is rectangular, the size is about 2.6mm multiplied by 3.0mm, the depth is about 0.7mm, the grinding area and a surrounding matrix are in smooth large-diameter circular arc transition, the grinding area and the surrounding area are cleaned by adopting acetone, and the grinding area and the surrounding area are dried by using a blower;

4. and (3) repairing track programming: according to the shape and the size of the area to be repaired of the guide blade, the designed forming track mode of the part to be repaired is in a shape like a Chinese character ji, and the included angle between the forming directions of the repaired odd layer and the repaired even layer is 90 degrees;

5. laser direct deposition repair: repairing and forming the polished area by using Arnold laser direct deposition equipment, and reserving a machining allowance of 0.5-1.0 mm, wherein the repairing process parameters are as follows: the laser power of the first repairing layer adjacent to the blade substrate is 500W, the laser scanning speed is 700mm/min, the powder feeding speed is 4g/min, the lap joint rate between passes is 50%, the coaxial protective gas flow rate is 15L/min, the laser power of the second repairing layer and the repairing layers above is 700W, the laser scanning speed is 700mm/min, the powder feeding speed is 6g/min, the lap joint rate between passes is 50%, and the coaxial protective gas flow rate is 15L/min;

6. and (3) finishing the size of the repair area: the surface of the repair area is subjected to excess material processing by adopting a handheld grinding tool, so that the repair area and the guide blade matrix are smooth and flush, and the size of the repair area meets the use requirement;

7. nondestructive detection of the repaired part: and (3) performing surface and internal quality inspection on the repair area and the peripheral area thereof by adopting a fluorescent flaw detection and X-ray method, and not finding defects such as cracks, unfused fusion, pores and the like.

Laser direct deposition repair tests were performed on K447A alloy test panels and the room temperature tensile and durability properties of the repaired joints were tested. The experimental result shows that the average room-temperature tensile strength of the repaired joint can reach 1050MPa, which is 93.5% of the actual measured value (1117MPa) of the base material, and the service life of the repaired joint is 51.5h under the condition of 980 ℃/160MPa, which all reach the use requirement of the K447A alloy guide vane.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the present invention, and these modifications or substitutions should be covered within the scope of the present invention.