CN113106445B - Laser cladding method - Google Patents

Abstract

The invention discloses a laser cladding method, which relates to the technical field of laser cladding, so as to improve the welding performance of alloy materials, crack the wear-resistant layer, and improve the performance and quality of the wear-resistant layer. The alloy materials include cobalt-based alloy materials and nickel-based alloy materials. Among them, in terms of mass percentage, the alloy material includes 7% to 10% of nickel-based alloy material, and the rest is cobalt-based alloy material. The laser cladding method includes: providing a preform having a damping surface. Using the alloy material proposed in the above technical solution as the cladding material, laser cladding equipment is used to carry out the cladding operation on the damping surface along the extending direction of the damping surface to obtain a wear-resistant layer formed on the damping surface. The wear-resistant layer includes at least one cladding layer, and each cladding layer is composed of N melt channels. The alloy material provided by the present invention is used to form a wear-resistant layer.

Description

A kind of laser cladding method

technical field

The invention relates to the technical field of laser cladding, in particular to a laser cladding method.

Background technique

The turbine rotor blades are the key components of the engine, and the contact surface between the turbine rotor blades is the damping surface of the blade crown. In the process of use, they collide and rub against each other, causing wear and tear, which increases the gap between the blade crowns. Under the action of high-temperature and high-pressure gas, the bending moment of the blade root increases, causing cracks at the root of the blade, resulting in blade fracture accidents.

In the prior art, in order to improve the service life of the blade, argon arc surfacing is used, and an alloy material is surfacing on the damping surface of the blade crown to form a wear-resistant layer. However, the existing alloy materials have poor weldability and are prone to cracks, which affect the performance and quality of the wear-resistant layer.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a laser cladding method to improve the welding performance of alloy materials, crack the wear-resistant layer, and improve the performance and quality of the wear-resistant layer.

In a first aspect, the present invention provides an alloy material. The alloy material includes cobalt-based alloy material and nickel-based alloy material. Among them, in terms of mass percentage, the alloy material includes 7% to 10% of nickel-based alloy material, and the rest is cobalt-based alloy material.

In the case of adopting the above technical solution, the alloy material includes a cobalt-based alloy material and a nickel-based alloy material. Cobalt-based alloy materials have good high temperature wear resistance, but poor weldability and easy cracking. The nickel-based alloy material has good high temperature resistance, good weldability, but poor wear resistance. The alloy material takes into account the advantages of cobalt-based alloy material and nickel-based alloy material, so that the alloy material has good weldability and high temperature wear resistance. In addition, since the alloy material includes cobalt-based alloy material and nickel-based alloy material, after cladding, the alloy material can form a metallurgical bond with the substrate, with good bonding strength, dense weave, better wear resistance, and stable processability. In addition, the alloy material including the cobalt-based alloy material and the nickel-based alloy material also has the properties of acid corrosion resistance and stress corrosion resistance, which improves the service life of the wear-resistant layer formed by the cladding of the alloy material.

Not only that, the inventor's research shows that the proportion of nickel-based alloy materials in the alloy materials is too low, and the alloy materials are prone to crack when cladding for many times; The strength and wear resistance of the wear-resistant layer formed by the coating are significantly reduced. In terms of mass percentage, the alloy material includes 7% to 10% of nickel-based alloy material, and the rest is cobalt-based alloy material. The strength and wear resistance of the wear-resistant layer are not much different, which can meet the strength and wear resistance requirements of the wear-resistant layer.

In a second aspect, the present invention also provides a laser cladding method. The laser cladding method includes:

A preform is provided, the preform has a damping surface.

And using the alloy material described in the first aspect as a cladding material, a laser cladding device is used to perform a cladding operation on the damping surface along the extending direction of the damping surface to obtain a wear-resistant layer formed on the damping surface. The wear-resistant layer includes at least one cladding layer, and each cladding layer is composed of N melt channels. N is an integer greater than or equal to 1.

The beneficial effects of the laser cladding method provided in the second aspect are the same as those of the alloy material described in the first aspect, and will not be repeated here.

Description of drawings

The accompanying drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 and 2 are metallographic structure diagrams in the embodiments of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined. "Several" means one or more than one, unless expressly specifically defined otherwise.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. are based on those shown in the accompanying drawings The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; may be mechanical connection or electrical connection; may be direct connection or indirect connection through an intermediate medium, may be internal communication between two elements or an interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

The turbine rotor blades are the key components of the engine, and the contact surface between the turbine rotor blades is the "Z-shaped" damping surface of the blade crown. In the process of use, they collide and rub against each other, causing wear and tear, which increases the gap between the blade crowns. Under the action of high-temperature and high-pressure gas, the bending moment of the blade root increases, causing cracks at the root of the blade, resulting in blade fracture accidents.

In the prior art, in order to improve the service life of the blade, argon arc surfacing is used, and an alloy material is surfacing on the damping surface of the blade crown to form a wear-resistant layer. However, the existing alloy materials have poor weldability and are prone to cracks, which affect the performance and quality of the wear-resistant layer. Moreover, the use of argon arc surfacing has the disadvantages of low pass rate of primary surfacing, large heat-affected zone, large residual stress, easy cracking in subsequent machining, poor controllability, and high requirements for operators.

Embodiments of the present invention provide an alloy material. The alloy material includes cobalt-based alloy material and nickel-based alloy material. Among them, in terms of mass percentage, the alloy material includes 7% to 10% of nickel-based alloy material, and the rest is cobalt-based alloy material.

In one example, the alloy material includes 7%, 8%, or 10% nickel-based alloy material, and the rest is cobalt-based alloy material in mass percent.

The above-mentioned nickel-based alloy material may be GH738 nickel-based alloy or GH625 nickel-based alloy. GH738 nickel-based alloy or GH625 nickel-based alloy has good high temperature resistance and good weldability. When used as alloy material with cobalt-based alloy material, the alloy material has good weldability and high temperature wear resistance.

The above-mentioned cobalt-based alloy material may be 800 cobalt-based alloy. 800 cobalt-based alloy has good high temperature wear resistance, and when used as alloy material with nickel-based alloy material, the alloy material has good weldability and high temperature wear resistance.

In the case of adopting the above technical solution, the alloy material includes a cobalt-based alloy material and a nickel-based alloy material. Cobalt-based alloy materials have good high temperature wear resistance, but poor weldability and easy cracking. The nickel-based alloy material has good high temperature resistance, good weldability, but poor wear resistance. The alloy material takes into account the advantages of cobalt-based alloy material and nickel-based alloy material, so that the alloy material has good weldability and high temperature wear resistance. In addition, since the alloy material includes cobalt-based alloy material and nickel-based alloy material, after cladding, the alloy material can form a metallurgical bond with the substrate, with good bonding strength, dense weave, better wear resistance, and stable processability. In addition, the alloy material including the cobalt-based alloy material and the nickel-based alloy material also has the properties of acid corrosion resistance and stress corrosion resistance, which improves the service life of the wear-resistant layer formed by the cladding of the alloy material.

Not only that, the inventor's research shows that the proportion of nickel-based alloy materials in the alloy materials is too low, and the alloy materials are prone to crack when cladding for many times; The strength and wear resistance of the wear-resistant layer formed by the coating are significantly reduced. In terms of mass percentage, the alloy material includes 7% to 10% of nickel-based alloy material, and the rest is cobalt-based alloy material. The strength and wear resistance of the wear-resistant layer are not much different, which can meet the strength and wear resistance requirements of the wear-resistant layer.

The invention also provides a laser cladding method. The laser cladding method includes:

Step S100: Provide a preform with a damping surface. The preform may be, but not limited to, a shroud of a turbine rotor blade. The above-mentioned damping surface is the "Z-shaped" damping surface of the blade crown. A typical blade shroud has two "Z-shaped" damping surfaces.

The above-mentioned preforms may be cleaned preforms. When the prefabricated part is the blade crown of the turbine rotating blade, the damping surface of the blade crown to be treated and the 2mm range around the damping surface can be ground to remove oxide scale, surface debris, etc., and then washed with acetone and dried to obtain the cleaned prefabricated parts.

In the case of using the above technical solution, the prefabricated parts are cleaned prefabricated parts, which can prevent defects such as pores and unfusion during the cladding process, so as to facilitate the formation of a better metallurgical bond between the cladding layer and the substrate, and improve the cladding process. quality.

In practical applications, the prepared preform is fixed at the installation position of the laser cladding equipment with a fixture, so that the tip of the cladding head of the laser cladding equipment can safely reach the damping surface of the preform, which is convenient for more efficient and accurate proofreading The start and end points of cladding ensure that the cladding path is not disturbed.

When the preform has multiple damping surfaces, a fixture with rotation and positioning functions can be used to fix the preform. After the cladding completes a damping surface, the fixture can rotate the preform, so that the laser cladding equipment can clad the preform. of multiple damping surfaces. Of course, the jig does not have the function of rotation and positioning. After the cladding completes a damping surface, manually adjust the installation position of the preform on the jig, so as to clad other damping surfaces of the preform, and it is also possible to clad other damping surfaces of the preform. A damping surface is clad.

Step 200 : using the above alloy material as a cladding material, use a laser cladding device to perform a cladding operation on the damping surface along the extending direction of the damping surface to obtain a wear-resistant layer formed on the damping surface. The wear-resistant layer includes at least one cladding layer, and each cladding layer is composed of N melt channels. N is an integer greater than or equal to 1.

In an example, cobalt-based alloy powder and nickel-based alloy powder can be mixed uniformly in advance in proportion to form alloy powder, and then the alloy powder can be used as cladding powder to be clad by laser cladding equipment to form a wear-resistant layer.

In another example, the cobalt-based alloy powder and the nickel-based alloy powder in the above-mentioned alloy materials can be transported to the molten pool in proportion through different powder feeding pipes of the laser cladding equipment, respectively, for cladding to form a wear-resistant layer.

In the case of using the above technical solution, the laser cladding method is used to use the alloy material as the cladding material to obtain a wear-resistant layer formed on the damping surface, which has the characteristics of concentrated energy density, small heat-affected zone, small deformation, smaller crack tendency, The cladding of more wear-resistant materials is less prone to cracks, and the obtained wear-resistant layer has the advantages of strong wear resistance, long service life, precise controllability and easy automation. When laser cladding technology is used to obtain the wear-resistant layer formed on the damping surface, a metallurgical bond can be formed between the cladding material and the substrate. The wear-resistant layer has a higher bonding strength, and the wear-resistant layer is more stable and stable during use. durable.

During the cladding process using the laser cladding equipment, it is necessary to move the nozzle of the laser cladding head to a position near the damping surface, and perform calibration according to the scanning direction and scanning path.

In one example, the calibration points are 1 o'clock to 6 o'clock. Among them, 1 point, 3 points and 5 points are distributed on one side edge of the damping surface along the extension direction of the damping surface, and 1 point and 5 points are divided into two ends of the damping surface. Points 2, 4, and 6 are distributed on the other edge of the damping surface along the extension direction of the damping surface. Point 2 corresponds to point 1, point 4 corresponds to point 3, and point 6 corresponds to point 5. According to the position of the calibration point, the number of weld tracks N of each cladding layer and the parameters of laser cladding are calculated to ensure that the edge of the damping surface can be clad in the cladding process. The laser cladding parameters may include at least one of the cladding scan direction, the cladding path, the shape of the cladding channel, and the number of cladding layers.

The above-mentioned number of cladding layers may be one layer or multiple layers. The number of cladding layers is set according to the requirements of the thickness of the wear-resistant layer on the damping surface of different preforms.

The above-mentioned melt channel number N can satisfy: N=2L/W. W is the width of the weld channel, and L is the extension length of the damping surface, so that there is a suitable amount of overlap between adjacent weld channels and the cladding quality of the cladding layer is improved.

The width of the melt channel may be 1.2mm˜1.5mm. The overlap amount of adjacent weld channels can be 0.6mm to 0.7mm. The overlap amount of adjacent weld channels has a great influence on the cladding quality of the cladding layer. If the overlap amount is too large or too small, it is easy to cause pores or inclusions. and other defects.

In one example, L=9mm, W=1.5mm, so N=2×9/1.5=12.

The laser cladding parameters of the above-mentioned laser cladding equipment also include the powder feeding amount of the alloy material powder, and the powder feeding amount can be 6g/min～8g/min.

The laser cladding power of the at least one cladding layer may be 320W to 420W.

In the above same cladding layer, the laser cladding power P of the k-th weld of the N welds is less than the laser cladding power P _max of the first weld, and greater than the laser cladding power P of the Nth weld. _min . 1<k<N. Among them, the laser cladding power P of the k-th weld track: P=P _max -(P _max -P _min )(k-2)/k.

When the wear-resistant layer includes multiple cladding layers, the laser cladding power of the cladding layer decreases along the increasing direction of the layer thickness of the cladding layer. Since the former cladding layer has a preheating effect on the latter cladding layer, the laser cladding power of the cladding layer decreases along the increasing direction of the layer thickness of the cladding layer, which can ensure that the energy on the damping surface is uniform Therefore, in the cladding process, defects such as cladding collapse or undercut are not easy to appear.

In one example, the wear layer includes two cladding layers. The laser cladding power P _max =420W of the first weld track of the first cladding layer, and the laser cladding power P _min =360W of the Nth weld track of the first cladding layer. When k=4, the laser cladding power P=420-(420-360)(4-2)/4=390W of the fourth welding track. When k=5, the laser cladding power P=420-(420-360)(5-2)/5=384W of the fifth welding track. When k=6, the laser cladding power P=420-(420-360)(6-2)/6=380W of the sixth welding track. It can be seen from this that the laser cladding power of the intermediate weld channel in the same cladding layer decreases sequentially.

The laser cladding power P _max =390W of the first weld track of the second cladding layer, and the laser cladding power P _min =320W of the Nth weld track of the second cladding layer. When k=4, the laser cladding power P=390-(390-320)(4-2)/4=355W of the fourth welding track. When k=5, the laser cladding power P=390-(390-320)(5-2)/5=348W of the fifth welding track. When k=6, the laser cladding power P=390-(390-320)(6-2)/6=343W of the sixth welding track.

In the case of adopting the above technical solution, the laser cladding power P of the kth weld track of the N weld tracks is less than the laser cladding power P _max of the first weld track, and is greater than the laser cladding power of the Nth weld track. P _min . 1<k<N. Among them, the laser cladding power P of the k-th weld track: P=P _max -(P _max -P _min )(k-2)/k. Based on this, in the process of cladding multiple weld channels by the laser cladding equipment, the laser cladding power of the intermediate weld channels in the same cladding layer decreases sequentially. In the cladding process, the former cladding channel has a preheating effect on the latter cladding channel, therefore, the laser cladding power of the middle cladding channel in the same cladding layer decreases in turn, which can ensure that the damping power is reduced during the cladding process. The energy on the surface is uniform, so that defects such as cladding collapse or undercut are not easy to appear during the cladding process.

The laser cladding parameters of the above-mentioned laser cladding equipment also include the scanning speed of the laser cladding equipment, and the scanning speed of the laser cladding equipment may be 2 mm/s to 4 mm/s. In practical applications, the appropriate scanning speed is matched according to parameters such as laser cladding power and powder feeding amount.

The above-mentioned laser cladding equipment may have a plurality of weld channel formation cycles. Each melt channel forming period includes a laser light-emitting period and a laser light-closing period. During the laser emitting period, the laser cladding equipment performs laser cladding. When the laser is closed, the laser cladding equipment suspends cladding. Along the distribution direction of the plurality of melt channels, the laser light-off period included in the corresponding melt channel formation cycle of each melt channel increases.

The time length difference between the laser light-off periods corresponding to the above-mentioned adjacent melt tracks may be 1 second to 2 seconds. For example, the time length difference between the corresponding laser light-off periods of adjacent melt tracks may be 1 second, 1.5 seconds or 2 seconds.

In the above N melt lanes, in the i-th to N-th melt lanes, the duration of the laser light-off period between adjacent melt lanes is 16 seconds or more. That is to say, in the same cladding layer, the duration of the laser light-off period included in the later several melt channel formation cycles is more than 16 seconds.

In the above N melt lanes, the duration of the laser light-off period between the N-1th melt lane and the Nth melt lane is more than 20 seconds. That is, the duration of the laser shut-off period between the last melt lane and the last melt lane is more than 20 seconds.

In an example, when N=12 and i=9, the duration of the laser light-off period between the ninth and tenth melt lanes, the length of the laser light-off period between the ninth melt lane and the tenth melt lane, and the difference between the tenth melt lane and the eleventh melt lane The duration of the laser light-off period between the 11th and the twelfth melt track is more than 16 seconds.

In an example, when N=12, i=9, the difference in duration of the laser light-off periods corresponding to adjacent melt lanes is 1.5 seconds, and the laser light-off period between the ninth melt lane and the tenth melt lane is When the duration of the period is 17 seconds, the duration of the laser light-off period between the tenth and eleventh melt lanes is 18.5 seconds, and the laser light between the eleventh melt lane and the twelfth melt lane is 18.5 seconds. The duration of the light-off period is 20 seconds.

When the wear-resistant layer includes multiple cladding layers, the laser cladding apparatus may have a plurality of cladding layer forming cycles. Each cladding layer formation cycle includes a cladding period and a pause period, and the pause period is 10 seconds to 14 seconds. For example: the pause period can be 10 seconds, 12 seconds or 14 seconds. During the cladding period, the laser cladding equipment clads each cladding layer. When the laser cladding equipment has a plurality of weld channel formation cycles, the cladding period includes a plurality of weld channel formation cycles. During the suspension period, the laser cladding equipment suspends cladding.

Laser closing time is particularly important for cladding forming. Improper selection of laser closing time may easily cause defects such as collapse or undercut. In the case of adopting the above technical solution, the occurrence of defects such as collapse or undercut can be reduced.

In practical applications, before the laser cladding equipment clads the wear-resistant layer, according to the determined laser cladding parameters, pre-laser the wear-resistant layer on the simulated prototype to preview the forming effect and quality to ensure the actual damping effect. The quality of the wear-resistant layer formed on the surface. It is also possible to set a variety of different laser cladding parameters on the system corresponding to different damping surfaces, and to clad different damping surfaces, select the corresponding laser cladding parameters.

Finally, the cladding of the wear-resistant layer is completed on the damping surface of the preform by the laser cladding equipment to obtain the cladding preform.

In practical applications, after removing the preform after the cladding layer is obtained, the wear-resistant layer needs to be ground and modified. For example, using hand sanding and polishing to complete sanding and retouching. Finally, non-destructive testing is performed on the position of the wear-resistant layer of the preform to ensure the quality and quality of the cladding. For example, whether the surface of the wear-resistant layer is defective or not, and whether the wear-resistant performance of the wear-resistant layer meets the technical requirements, is detected by fluorescence.

Using the above-mentioned laser cladding method, the above-mentioned alloy material is used as a cladding material, and a cladding operation is performed on the damping surface of the turbine rotor blade to obtain a wear-resistant layer formed on the damping surface. The material of the turbine rotor blades is a nickel-based precipitation-strengthened directionally solidified columnar superalloy. Good, high plasticity, stable organization, low cost, poor wear resistance and other characteristics. Nickel-based precipitation-strengthened directional solidification columnar superalloys are commonly used materials for turbine rotor blades, guide vanes and other high-temperature components. They have excellent comprehensive performance under complex and harsh working conditions such as high temperature, high pressure, and high speed.

1 and 2 illustrate the metallographic structure diagrams in the embodiments of the present invention. As shown in Figures 1 and 2, the microstructure of the cladding layer was observed by metallographic analysis, and it was found that the cladding layer had a dense structure, uniform grains, no unfused, no pores, no microscopic cracks and other defects. The base material of the blade crown damping surface forms a metallurgical bond, and the bonding performance is good.

The alloy material and the laser cladding method provided by the present invention will be described in detail below with reference to the examples. The following examples are only for the explanation of the present invention, but not for limitation. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

The alloy material in this embodiment, in terms of mass percentage, includes 7% of GH738 nickel-based alloy and 93% of 800 cobalt-based alloy.

The laser cladding method provided in this embodiment includes the following steps:

Provides the shroud of the turbine rotating blade, and the damping surface is the "Z-shaped" damping surface of the shroud. The material of the blade crown is a nickel-based precipitation-strengthened directional solidification columnar superalloy.

The damping surface of the leaf crown and the 2 mm range around the damping surface were polished to remove oxide scale, surface debris, etc., and then washed with acetone and dried to obtain a cleaned leaf crown.

Fix the cleaned leaf crown at the installation position of the laser cladding equipment with a fixture, so that the tip of the cladding head of the laser cladding equipment can safely reach the damping surface of the preform.

According to the mass percentage, 7% of GH738 nickel-based alloy powder and 93% of 800 cobalt-based alloy powder were mixed into alloy powder, and the alloy powder was added as cladding powder to the laser cladding equipment for cladding, and the formation on the damping surface was obtained. wear-resistant layer.

During the cladding process, move the nozzle of the laser cladding head to a position near the damping surface, and perform calibration according to the scanning direction and scanning path. According to the position of the calibration point, the extension length L=9mm of the damping surface is measured.

The width of the melt channel is W=1.2mm. The number of melt channels N=2L/W=15. The overlap of adjacent melt channels is 0.6mm.

The powder feeding rate of the laser cladding equipment is 6g/min. The scanning speed of the laser cladding equipment is 2mm/s.

The number of cladding layers is two. The laser cladding power P _max =420W of the first weld track of the first cladding layer; the laser cladding power P _min =360W of the fifteenth weld track of the first cladding layer. The laser cladding power of the middle melt channel of the first layer of cladding layer (the second melt channel to the fourteenth melt channel) is: 420W, 400W, 390W, 384W, 380W, 377W, 375W, 373W, 372W, 371W , 370W, 369W, 368W.

In the first layer of cladding layer, from the first melt channel to the fifteenth melt channel, the duration of the laser light-off period between adjacent melt channels is: 7s, 8s, 9s, 10s, 11s, 12s, 13s , 14s, 15s, 16s, 17s, 18s, 19s, 20s.

The laser cladding power of the first weld of the second cladding layer is P _max =390W; the laser cladding power of the fifteenth weld of the second cladding layer is P _min =320W. The laser cladding power of the second layer of cladding layer in the middle channel (the second channel to the fourteenth channel) is: 390W, 367W, 355W, 348W, 343W, 340W, 338W, 336W, 334W, 333W , 332W, 331W, 330W.

The duration of the pause period between the first cladding layer and the second cladding layer was 12 seconds.

In the second layer of cladding layer, from the first melt channel to the fifteenth melt channel, the duration of the laser light-off period between adjacent melt channels is: 7s, 8s, 9s, 10s, 11s, 12s, 13s , 14s, 15s, 16s, 17s, 18s, 19s, 20s.

Finally, the blade crown after obtaining the cladding layer is removed, and the wear-resistant layer is polished by hand to complete the grinding and shaping. Non-destructive testing of the position of the wear-resistant layer is carried out to ensure the quality and quality of the cladding.

Example 2

The alloy material in this embodiment, in terms of mass percentage, includes 10% of GH625 nickel-based alloy and 90% of 800 cobalt-based alloy.

The laser cladding method provided in this embodiment includes the following steps:

Provides the shroud of the turbine rotating blade, and the damping surface is the "Z-shaped" damping surface of the shroud. The material of the blade crown is a nickel-based precipitation-strengthened directional solidification columnar superalloy.

The damping surface of the leaf crown and the 2 mm range around the damping surface were polished to remove oxide scale, surface debris, etc., and then washed with acetone and dried to obtain a cleaned leaf crown.

Fix the cleaned leaf crown at the installation position of the laser cladding equipment with a fixture, so that the tip of the cladding head of the laser cladding equipment can safely reach the damping surface of the preform.

According to the mass percentage, 10% of GH625 nickel-based alloy powder and 90% of 800 cobalt-based alloy powder were mixed into alloy powder, and the alloy powder was added as cladding powder to the laser cladding equipment for cladding, and the formation on the damping surface was obtained. wear-resistant layer.

During the cladding process, move the nozzle of the laser cladding head to a position near the damping surface, and perform calibration according to the scanning direction and scanning path. According to the position of the calibration point, the extension length L=9mm of the damping surface is measured.

The width of the melt channel is W=1.5mm. The number of melt channels N=2L/W=12. The overlap of adjacent melt channels is 0.7mm.

The powder feeding rate of the laser cladding equipment is 8g/min. The scanning speed of the laser cladding equipment is 4mm/s.

The number of cladding layers is one layer. The laser cladding power of the first cladding track is P _max =420W; the laser cladding power of the twelfth cladding track of the first cladding layer is P _min =360W. The laser cladding power of the middle melt track (the second melt track to the eleventh melt track) is: 420W, 400W, 390W, 384W, 380W, 377W, 375W, 373W, 372W, 371W.

From the first melt track to the twelfth melt track, the duration of the laser light-off period between adjacent melt tracks is: 5s, 6.5s, 8s, 9.5s, 11s, 12.5s, 14s, 15.5s, 17s , 18.5s, 20s.

Finally, the blade crown after obtaining the cladding layer is removed, and the wear-resistant layer is polished by hand to complete the grinding and modification. Non-destructive testing of the position of the wear-resistant layer is carried out to ensure the quality and quality of the cladding.

Example 3

The alloy material in this embodiment, in terms of mass percentage, includes 8% of GH738 nickel-based alloy and 92% of 800 cobalt-based alloy.

The laser cladding method provided in this embodiment includes the following steps:

Provides the shroud of the turbine rotating blade, and the damping surface is the "Z-shaped" damping surface of the shroud. The material of the blade crown is a nickel-based precipitation-strengthened directional solidification columnar superalloy.

The damping surface of the leaf crown and the 2 mm range around the damping surface were polished to remove oxide scale, surface debris, etc., and then washed with acetone and dried to obtain a cleaned leaf crown.

Fix the cleaned leaf crown at the installation position of the laser cladding equipment with a fixture, so that the tip of the cladding head of the laser cladding equipment can safely reach the damping surface of the preform.

According to the mass percentage, 8% of GH738 nickel-based alloy powder and 92% of 800 cobalt-based alloy powder were mixed into alloy powder, and the alloy powder was added as cladding powder to the laser cladding equipment for cladding, and the formation on the damping surface was obtained. wear-resistant layer.

During the cladding process, move the nozzle of the laser cladding head to a position near the damping surface, and perform calibration according to the scanning direction and scanning path. According to the position of the calibration point, the extension length L=9mm of the damping surface is measured.

The width of the melt channel is W=1.5mm. The number of melt channels N=2L/W=12. The overlap of adjacent melt channels is 0.65mm.

The powder feeding rate of the laser cladding equipment is 7g/min. The scanning speed of the laser cladding equipment is 3mm/s.

The number of cladding layers is two. The laser cladding power P _max =420W of the first weld track of the first cladding layer; the laser cladding power P _min =360W of the twelfth weld track of the first cladding layer. The laser cladding power of the first layer of cladding layer in the middle channel (the second channel to the eleventh channel) is: 420W, 400W, 390W, 384W, 380W, 377W, 375W, 373W, 372W, 371W .

In the first layer of cladding layer, from the first melt channel to the twelfth melt channel, the duration of the laser light-off period between adjacent melt channels is: 4s, 6s, 8s, 10s, 12s, 14s, 16s , 18s, 20s, 22s, 24s.

The laser cladding power of the first weld of the second cladding layer is P _max =390W; the laser cladding power of the twelfth weld of the second cladding layer is P _min =320W. The laser cladding power of the second cladding layer in the middle track (the second track to the eleventh track) is: 390W, 367W, 355W, 348W, 343W, 340W, 338W, 336W, 334W, 333W .

The duration of the pause period between the first cladding layer and the second cladding layer was 10 seconds.

In the second layer of cladding layer, from the first melt channel to the twelfth melt channel, the duration of the laser light-off period between adjacent melt channels is: 4s, 6s, 8s, 10s, 12s, 14s, 16s , 18s, 20s, 22s, 24s.

Finally, the blade crown after obtaining the cladding layer is removed, and the wear-resistant layer is polished by hand to complete the grinding and modification. Non-destructive testing of the position of the wear-resistant layer is carried out to ensure the quality and quality of the cladding. In the foregoing description of the embodiments, the particular features, structures, materials or characteristics may be combined in any suitable manner in any one or more of the embodiments or examples.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (8)

1. a laser cladding method, is characterized in that, comprises: providing a preform having a damping surface; and an alloy material, the alloy material is a cladding material, and in mass percentage, the alloy material includes 7% to 10% of nickel-based alloy material, and the rest is cobalt-based alloy material; laser cladding equipment is used along the A cladding operation is performed on the damping surface along the extending direction of the damping surface to obtain a wear-resistant layer formed on the damping surface; the wear-resistant layer includes at least one cladding layer, and each layer of the cladding layer is composed of N melt tunnels, N is an integer greater than or equal to 1; In the same cladding layer, the laser cladding power P of the k-th weld track of the N weld tracks is less than the laser cladding power P _max of the first weld track, and greater than the laser cladding power of the N-th weld track. Cladding power P _min ; 1<k<N; wherein, the laser cladding power P of the k-th weld track: P=P _max -(P _max -P _min )(k−2)/k. 2 . The laser cladding method according to claim 1 , wherein N=2L/W, W is the width of the weld channel, and L is the extension length of the damping surface. 3 . 3 . The laser cladding method according to claim 1 , wherein the width of the weld channel is 1.2mm˜1.5mm; and/or, The overlapping amount of the adjacent fusion channels is 0.6mm˜0.7mm. 4. laser cladding method according to claim 1, is characterized in that, When the wear-resistant layer includes multiple cladding layers, the laser cladding power of the cladding layer decreases along the direction of increasing layer thickness of the cladding layer; and/or, The laser cladding power of the at least one cladding layer is 320W-420W. 5. The laser cladding method according to claim 1, wherein the laser cladding equipment has a plurality of weld channel formation periods, and each weld channel formation period includes a laser light emitting period and a laser light closing period; In the distribution direction of the plurality of the melt channels, the laser light-off period included in the corresponding melt channel formation cycle of each of the melt channels increases. 6 . The laser cladding method according to claim 5 , wherein the difference in the duration of the laser light-off periods corresponding to the adjacent weld tracks is 1 to 2 seconds; and/or, Among the N melt lanes, in the i-th to N-th melt lanes, the duration of the laser light-off period between the adjacent melt lanes is more than 16 seconds; In the N melt lanes, the duration of the laser light-off period between the N-1th melt lane and the Nth melt lane is more than 20 seconds; and/or, The laser cladding equipment has a plurality of cladding layer forming cycles, each cladding layer forming cycle includes a cladding period and a pause period, and the pause period is 10 seconds to 14 seconds. 7. The laser cladding method according to any one of claims 2 to 6, wherein the laser cladding parameters of the laser cladding equipment further include a powder feeding amount of the alloy material powder, and the powder feeding amount is 6g/min～8g/min; and/or, The laser cladding parameters of the laser cladding equipment further include the scanning speed of the laser cladding equipment, and the scanning speed of the laser cladding equipment is 2mm/s～4mm/s; and/or, The laser cladding parameters of the laser cladding equipment further include: at least one of the cladding scanning direction, the cladding path, the shape of the cladding channel, and the number of cladding layers. 8. The laser cladding method according to any one of claims 2 to 6, wherein the preform is a cleaned preform; The preform is a blade shroud of a turbine rotor blade.

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