CN119057062A

CN119057062A - Alloy powder for repairing damage to ductile iron parts and damage repair method

Info

Publication number: CN119057062A
Application number: CN202411561299.8A
Authority: CN
Inventors: 张鹏飞; 张于胜; 李珂尧; 成扬; 邱龙时; 胡小刚
Original assignee: Xian Rare Metal Materials Research Institute Co Ltd
Current assignee: Xian Rare Metal Materials Research Institute Co Ltd
Priority date: 2024-11-04
Filing date: 2024-11-04
Publication date: 2024-12-03

Abstract

The disclosure provides alloy powder for repairing ductile iron component damage and a ductile iron component damage repairing method based on an ultra-high-speed laser cladding technology, and relates to the technical field of surface repairing. The alloy powder for repairing the damage of the ductile iron component comprises 70 to 80 weight percent of iron-nickel-chromium alloy powder and 20 to 30 weight percent of wear-resistant filler, wherein the iron-nickel-chromium alloy powder comprises 0.01 to 0.28 weight percent of C, 10 to 18 weight percent of Cr, 12 to 16 weight percent of Ni, 0.2 to 2 weight percent of Si, 2 to 10 weight percent of Mo, 0.3 to 0.4 weight percent of Nb, 0.2 to 0.4 weight percent of Mn and the balance of Fe. The repairing effect of the spheroidal graphite cast iron damaged area can be improved.

Description

Alloy powder for repairing damage of ductile iron component and damage repairing method

Technical Field

The disclosure relates to the technical field of surface repair, in particular to alloy powder for repairing damage of ductile cast iron parts and a ductile cast iron part damage repairing method based on an ultra-high-speed laser cladding technology.

Background

Cast iron is widely used in the fields of metallurgy, machine manufacturing, petrochemical industry, automobiles, ships and the like because of its excellent castability, antifriction property, shock absorption property and machinability. Among them, spheroidal graphite cast iron is often used in place of steel for modern industrial equipment such as large cylinders, gear cases, engine crankshafts, and the like due to its strength and toughness close to that of steel.

The ductile iron parts are used in the sea, the plateau and the desert for a long time, bear serious abrasion and corrosion under the environments of complex and changeable corrosion at high temperature and low temperature and high salinity, and easily cause serious damage and premature failure and scrapping of the parts or have defect damage in the production and manufacturing process.

At present, the problem of poor repair effect exists in the damage repair scheme of the spheroidal graphite cast iron.

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the present disclosure and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The invention aims to provide alloy powder for repairing ductile cast iron component damage and a ductile cast iron component damage repairing method based on a super-high-speed laser cladding technology, and further solve the problem that the ductile cast iron damaged area is poor in repairing effect at least to a certain extent.

According to a first aspect of the present disclosure, there is provided an alloy powder for repairing damage to ductile iron parts, the alloy powder comprising 70 to 80wt% of an iron-nickel-chromium alloy powder and 20 to 30wt% of a wear-resistant filler, the iron-nickel-chromium alloy powder comprising 0.01 to 0.28wt% of C, 10 to 18wt% of Cr, 12 to 16wt% of Ni, 0.2 to 2wt% of Si, 2 to 10wt% of Mo, 0.3 to 0.4wt% of Nb, 0.2 to 0.4wt% of Mn, and the balance of Fe.

Optionally, the wear-resistant filler comprises 10 to 40wt% TiN, 10 to 30wt% CeO ₂, and 30 to 80wt% nickel-coated graphite.

Optionally, the nickel-coated graphite comprises 10wt% to 40wt% C and 60wt% to 90wt% Ni.

According to a second aspect of the disclosure, a method for repairing damage to a ductile iron component based on a superhigh speed laser cladding technology is provided, and the method comprises the steps of carrying out three-dimensional modeling on a damaged area of the ductile iron component, slicing a constructed model to obtain solid slice data, placing alloy powder for repairing the damage to the ductile iron component in a carrier gas type powder feeding cylinder, aligning a coaxial annular superhigh speed cladding head to the damaged area, starting a powder feeding system, and controlling the coaxial annular superhigh speed cladding head to execute a superhigh speed laser repairing process according to the solid slice data by taking laser as a heat source until the damaged area is filled up to obtain a ductile iron repair piece.

Optionally, the coaxial annular ultra-high speed cladding head is at a distance of 5.5mm to 6.5mm from the surface of the damaged area.

Optionally, argon with the flow of 8L/min to 15L/min is introduced into the coaxial annular ultra-high speed cladding head as shielding gas, wherein the powder feeding flow of the powder feeding system is 4L/min to 9L/min.

Optionally, in the ultra-high speed laser cladding technology, the diameter of a light spot is 1mm to 5mm, the laser power is 1500W to 2400W, the scanning speed is 900mm/min to 1200mm/min, the powder feeding speed is 0.3r/min to 1r/min, the lap joint rate is 45% to 75%, the width of a molten pool is 3mm to 5mm, and the height of the molten pool is 0.2mm to 1.2mm.

Optionally, before the ultrahigh-speed laser repair process is performed on the damaged area, the ductile iron component damage repair method further comprises polishing the damaged area, and cleaning the polished damaged area by using a cleaning agent.

Optionally, controlling the coaxial annular ultra-high speed cladding head to execute an ultra-high speed laser repair process according to the solid slice layer data until the damaged area is filled up to obtain the spheroidal graphite cast iron repair, including controlling the coaxial annular ultra-high speed cladding head to execute the ultra-high speed laser repair process according to the solid slice layer data until the damaged area is filled up to obtain an intermediate repair, standing the intermediate repair, air-cooling to room temperature, and carrying out surface grinding and polishing on the intermediate repair to obtain the spheroidal graphite cast iron repair.

Optionally, the repair path of the ultra-high speed laser repair process is reciprocating.

In the scheme of the exemplary embodiment of the disclosure, the alloy powder for repairing the damage of the ductile iron component comprises iron-nickel-chromium alloy powder and wear-resistant filler, and by utilizing the alloy powder of the component, good metallurgical bonding with the ductile iron matrix can be realized, and the ductile iron component is not easy to fall off. The repaired component has similar or exceeding the original substrate performance, uniform strength and better ductility. In addition, the combination of the wear-resistant filler is helpful for improving the wear resistance of the repair area.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. It will be apparent to those of ordinary skill in the art that the drawings in the following description are merely examples of the disclosure and that other drawings may be derived from them without undue effort.

Fig. 1 schematically illustrates a flowchart of a ductile iron component damage repair method according to an exemplary embodiment of the present disclosure.

Fig. 2 shows a macroscopic topography schematic of a repaired cross section of a ductile iron component of embodiment 1 of the present disclosure.

Fig. 3 shows a microscopic topography schematic of a repaired cross section of a ductile iron component of embodiment 1 of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein, but rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the present disclosure. One skilled in the relevant art will recognize, however, that the aspects of the disclosure may be practiced without one or more of the specific details, or with other methods, processes, steps, etc. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the present disclosure.

Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted. The flow diagrams depicted in the figures are exemplary only and not necessarily all steps are included. For example, some steps may be decomposed, and some steps may be combined or partially combined, so that the order of actual execution may be changed according to actual situations.

The method for repairing the damaged ductile iron component mainly comprises plasma spraying, electron beam welding, CO ₂ gas shielded welding, argon tungsten-arc welding, traditional laser cladding and the like. The technologies generally have the problems that the temperature input controllability is poor, the precision and the stability cannot be ensured, and the like, and the defects of air holes, cracks and the like are easy to generate after repair, so that the actual use requirements are difficult to meet.

Ultra-high-speed laser cladding is a surface modification technology with rapid heating and cooling, high efficiency and small deformation. The essential difference from the traditional laser cladding is that the powder melting position is changed, so that the powder is melted by being converged with laser in a flying space, and then a micro-molten pool is formed with the surface of the substrate. Compared with the traditional laser cladding, electroplating, overlaying welding, thermal spraying and the like, the method has the advantages of low dilution rate, high bonding strength, low surface roughness and the like, can replace the traditional electroplating technology, and is expected to efficiently solve the problem of damage repair of the nodular cast iron parts.

The invention provides a novel alloy powder for repairing surface damage of a spheroidal graphite cast iron part and a repairing method, wherein a superhigh-speed laser repairing technology is adopted to obtain a solid continuous and smooth repairing layer in a damaged area of the spheroidal graphite cast iron part, so that repairing and protecting effects are achieved, and the repairing layer has the advantages of high hardness, high wear resistance and good stability, can ensure normal operation of the part, reduces maintenance cost of the spheroidal graphite cast iron part, and reduces production loss caused by equipment shutdown.

First, the embodiment of the present disclosure provides a novel alloy powder for repairing damage to ductile iron parts, which includes 70wt% to 80wt% of iron-nickel-chromium alloy powder and 20wt% to 30wt% of wear-resistant filler.

The iron-nickel-chromium alloy powder may include 0.01wt% to 0.28wt% of C, 10wt% to 18wt% of Cr, 12wt% to 16wt% of Ni, 0.2wt% to 2wt% of Si, 2wt% to 10wt% of Mo, 0.3wt% to 0.4wt% of Nb, 0.2wt% to 0.4wt% of Mn, and the balance of Fe. Wherein the meaning of the balance Fe means that the Fe-Ni-Cr alloy powder contains the balance Fe except the above material components.

The wear resistant filler may include 10 to 40wt% TiN, 10 to 30wt% CeO ₂, and 30 to 80wt% nickel-coated graphite. Specifically, the nickel-coated graphite may include 10wt% to 40wt% of C and 60wt% to 90wt% of Ni.

In an exemplary embodiment of the present disclosure, the above alloy powder may be obtained after ball milling. For example, the substances of the above components are placed in a roller ball mill and thoroughly mixed for not less than 2 hours to obtain the above alloy powder.

According to some embodiments of the present disclosure, the alloy powder of the present disclosure has a particle size of 15 μm to 53 μm and a flowability of less than 50s/50g.

The ductile iron component damage repair method based on the ultra-high speed laser cladding technology according to the embodiment of the present disclosure will be described below with reference to fig. 1. Referring to fig. 1, the damage repair method of the embodiment of the present disclosure may include the steps of:

S12, performing three-dimensional modeling on the damaged area of the ductile cast iron component, and performing slicing treatment on the constructed model to obtain the solid slice layer data.

In exemplary embodiments of the present disclosure, it is understood that solid slice layers are used to plan a repair path for a laser cladding process.

And (3) polishing the damaged area of the solid ductile iron component, and cleaning the polished damaged area by using a cleaning agent. Wherein the cleaning agent can include, but is not limited to, acetone, absolute ethyl alcohol, environmental-friendly hydrocarbon, and the like.

S14, placing alloy powder for repairing the damage of the nodular cast iron part into a carrier gas type powder feeding cylinder, and aligning the coaxial annular ultrahigh-speed cladding head to the damaged area.

Specifically, the distance of the coaxial annular ultra-high speed cladding head from the surface of the damaged area may be controlled to be 5.5mm to 6.5mm.

S16, starting a powder feeding system, using laser as a heat source, and controlling the coaxial annular ultrahigh-speed cladding head to execute an ultrahigh-speed laser repairing process according to the layer data of the solid sheet until the damaged area is filled up, so as to obtain the nodular cast iron repairing piece.

Specifically, the coaxial annular ultra-high speed cladding head can be controlled to execute an ultra-high speed laser repairing process according to the solid slice layer data until the damaged area is filled up, so as to obtain an intermediate repairing piece. Next, the intermediate restoration is left to stand for air cooling to room temperature, and surface grinding and polishing are performed on the intermediate restoration to obtain a ductile cast iron restoration.

In the ultra-high speed laser repairing process, firstly, the melting height and the melting width of a molten pool are obtained through the technological parameters including the light spot size, the laser power, the scanning speed and the powder feeding amount. Then, the lap joint rate is selected, other parameters are kept unchanged in the repairing process, and the ultra-high-speed laser repairing is carried out only by adjusting the laser power and the powder feeding amount.

According to some embodiments of the present disclosure, in the ultra-high speed laser cladding technique, the spot diameter is 1mm to 5mm, the laser power is 1500W to 2400W, the scanning speed is 900mm/min to 1200mm/min, the powder feeding speed is 0.3r/min to 1r/min, the lap ratio is 45% to 75%, the molten pool width is 3mm to 5mm, and the molten pool height is 0.2mm to 1.2mm.

According to some embodiments of the present disclosure, argon gas with a flow rate of 8L/min to 15L/min is introduced as a shielding gas into a coaxial annular ultra-high speed cladding head. In addition, the powder feeding air flow of the powder feeding system is 4L/min to 9L/min.

For ultra-high laser repair paths, the present disclosure may be reciprocating.

The average hardness of the repair layer of the repair member obtained by the repair method of the embodiment of the disclosure is 410HV _0.1 to 460HV _0.1, the bonding strength is 420MPa to 490MPa, and the elongation is 3.7% to 4.1%.

Through the exemplary embodiment of the disclosure, in one aspect, the alloy powder of the disclosure is composed of iron-nickel-chromium alloy powder, tiN, ceO ₂ and nickel-coated graphite, and a repairing layer is deposited on the surface of the spheroidal graphite cast iron through rapid heating and rapid cooling by an ultra-high speed laser repairing technology. The nickel-coated graphite is decomposed into nickel and graphite, the graphite and the base material of the nodular cast iron component have good wettability, a NiTi hard phase is formed, and TiN and CeO ₂ respectively play roles of hard strengthening and fine-grain strengthening, so that the wear resistance of the repairing layer is further improved.

On the other hand, according to the scheme, alloy powder with high sphericity and narrow particle size distribution and fluidity of less than 50s/50g is selected as a repairing material, the mixed alloy powder is clad on a spheroidal graphite cast iron damaged area by adopting an optical fiber laser and a coaxial annular cladding head, after the area to be repaired is naturally cooled, good metallurgical bonding is formed with a spheroidal graphite cast iron matrix, and the repaired spheroidal graphite cast iron component has similar or exceeding the performance of a base material with the original spheroidal graphite cast iron material, and has uniform strength.

On the other hand, the proposal of the present disclosure considers the physical characteristics of the materials of the ball-milling cast iron, the heat input quantity of the laser beam, the melting width, the penetration, the lap continuity and other factors in the deposition process, and provides a super-high speed laser repairing process method for the damage of the ball-milling cast iron parts, which is properly fine-tuned according to the actual conditions within the process parameter range, and adjusts the laser power and the powder feeding quantity in the repairing process to carry out super-high speed laser repairing. The parameter adjustment process is easy to control, the repaired damaged area of the ductile cast iron component has fine and uniform tissue, good comprehensive mechanical property and far superior to the original ball-milling cast iron base material, and the repaired area is in powder metallurgical bonding, is not easy to fall off and has compact tissue.

In yet another aspect, the exemplary repair scheme of the present disclosure is applicable to damage of commonly used cast iron parts, has a clear process window range, is beneficial to industrial production, and facilitates automation. The heat input amount in the repairing process is stable, the splashing can be reduced, the generation of air holes, cracks and inclusion defects is reduced, the repairing working hours are shortened, and higher repairing efficiency and benefit are brought.

The following is a further description of exemplary aspects of the present disclosure by way of examples and comparative examples.

Example 1

The alloy powder for repairing the damage of the ductile iron component consists of 80 weight percent of Fe-Ni-Cr alloy powder and 20 weight percent of wear-resistant filler.

The iron-nickel-chromium alloy powder includes 0.08wt% of C,10wt% of Cr,14 wt% of Ni,0.2wt% of Si,10wt% of Mo,0.35wt% of Nb,0.2wt% of Mn and the balance of Fe.

The wear-resistant filler comprises 30wt% of TiN,20wt% of CeO ₂ and 50wt% of nickel-coated graphite. Wherein the nickel-coated graphite comprises 10wt% of C and 90wt% of Ni.

Specifically, the alloy powder was obtained by thoroughly mixing the above materials in a roller ball mill for 3 hours.

Aiming at the repairing process, firstly, the damaged part of the nodular cast iron part is polished, impurities affecting the cladding effect, such as rust, paint spraying and the like, are removed, and the surface is cleaned by adopting acetone. And simultaneously, carrying out three-dimensional modeling on the damaged area by using computer software, slicing the model to obtain solid slice layer data, planning a repair path by combining the width range of a single-pass deposition molten pool and the lap ratio of the ultra-high-speed laser repair, and introducing the repair path into an ultra-high-speed laser cladding control system.

And then placing the alloy powder into a carrier gas type powder feeding cylinder, aligning a coaxial annular cladding head to the surface to be repaired of the nodular cast iron part, wherein the distance between the cladding head and the surface to be repaired is 6mm, and introducing argon with the flow rate of 8L/min as shielding gas to feed the powder to flow rate of 9L/min.

The set process parameters comprise 3mm of light spot diameter, 2400W of laser power, 1200mm/min of scanning speed, 1r/min of powder feeding speed, 55% of lap joint rate, 5mm of molten pool width and 0.7mm of molten pool height.

And then, starting the powder feeding system, taking laser as a heat source, and enabling the coaxial annular ultrahigh-speed cladding head to execute an ultrahigh-speed laser repairing process according to the layer data of the solid sheets until each single solid sheet layer is stacked layer by layer according to a set repairing path to fill the area to be repaired.

And then, standing and air cooling the obtained repairing piece to room temperature, and grinding and polishing the surface of the repairing area to obtain the ductile cast iron repairing piece.

Fig. 2 is a macroscopic morphology diagram of a cross section of a coating after repairing a ductile iron component according to embodiment 1, and it can be seen from the figure that the coating after repairing the ductile iron component according to the embodiment has no cracks and a compact structure. Fig. 3 shows the microstructure morphology of the ductile iron component of example 1 after repair, which is seen to be composed of intergranular martensite and form a network structure.

Example 2

The alloy powder for repairing the damage of the ductile iron component consists of 70wt% of Fe-Ni-Cr alloy powder and 30wt% of wear-resistant filler.

The iron-nickel-chromium alloy powder includes 0.01wt% of C,18wt% of Cr,12 wt% of Ni,1.5wt% of Si,2wt% of Mo,0.3wt% of Nb,0.3wt% of Mn and the balance of Fe.

The wear-resistant filler comprises 10wt% of TiN,10wt% of CeO ₂ and 80wt% of nickel-coated graphite. Wherein the nickel-coated graphite comprises 40wt% of C and 60wt% of Ni.

And then placing the alloy powder into a carrier gas type powder feeding cylinder, aligning a coaxial annular cladding head to the surface to be repaired of the nodular cast iron part, wherein the distance between the cladding head and the surface to be repaired is 6.5mm, and introducing argon with the flow of 13L/min as shielding gas to feed the powder to flow 4L/min.

The set process parameters comprise 3mm of spot diameter, 1500W of laser power, 900mm/min of scanning speed, 0.4r/min of powder feeding speed, 75% of lap joint rate, 3.4mm of molten pool width and 1.2mm of molten pool height.

Example 3

The alloy powder for repairing the damage of the ductile iron component consists of 75 weight percent of Fe-Ni-Cr alloy powder and 25 weight percent of wear-resistant filler.

The iron-nickel-chromium alloy powder includes 0.28wt% of C,14wt% of Cr,16 wt% of Ni,2wt% of Si,7wt% of Mo,0.4wt% of Nb,0.4wt% of Mn and the balance of Fe.

The wear-resistant filler comprises 40wt% of TiN,30wt% of CeO ₂ and 30wt% of nickel-coated graphite. Wherein the nickel-coated graphite comprises 20wt% of C and 80wt% of Ni.

Specifically, the alloy powder was obtained by thoroughly mixing the above materials in a roller ball mill for 2.5 hours.

And then placing the alloy powder into a carrier gas type powder feeding cylinder, aligning a coaxial annular cladding head to the surface to be repaired of the nodular cast iron part, wherein the distance between the cladding head and the surface to be repaired is 5.5mm, and introducing argon with the flow rate of 15L/min as shielding gas to feed the powder to flow 7L/min.

The set process parameters comprise 3mm of light spot diameter, 1800W of laser power, 1000mm/min of scanning speed, 0.3r/min of powder feeding speed, 45% of overlap ratio, 3mm of molten pool width and 0.2mm of molten pool height.

Comparative example 1

The difference from example 1 is that the alloy powder used is 100wt% iron-nickel-chromium alloy powder.

Comparative example 2

The difference from example 1 is that the alloy powder used is 100% by weight of wear-resistant filler.

Comparative example 3

The difference from example 1 is that the alloy powder used does not contain Mo element.

The average hardness, bonding strength and elongation were measured for the repair areas corresponding to examples 1 to 3 and comparative examples 1 to 3, respectively, and the results are shown in Table 1:

TABLE 1

As can be seen in conjunction with table 1, applying the repair scheme of the embodiments of the present disclosure, the hardness of the repair area can reach 2 times the hardness of the ductile iron matrix. Compared with alloy powder not disclosed by the invention, the alloy powder formed by the embodiment of the invention has the advantages of improved performance and good repairing effect in terms of hardness, bonding strength and elongation.

It should be noted that although the steps of the methods in the present disclosure are depicted in the accompanying drawings in a particular order, this does not require or imply that the steps must be performed in that particular order, or that all illustrated steps be performed, to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step to perform, and/or one step decomposed into multiple steps to perform, etc.

Furthermore, the above-described figures are only schematic illustrations of processes included in the method according to the exemplary embodiments of the present disclosure, and are not intended to be limiting. It will be readily appreciated that the processes shown in the above figures do not indicate or limit the temporal order of these processes. In addition, it is also readily understood that these processes may be performed synchronously or asynchronously, for example, among a plurality of modules.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An alloy powder for repairing damage to ductile iron parts, characterized in that the alloy powder comprises 70 to 80wt% of iron-nickel-chromium alloy powder and 20 to 30wt% of wear-resistant filler;

The iron-nickel-chromium alloy powder includes 0.01wt% to 0.28wt% of C, 10wt% to 18wt% of Cr, 12wt% to 16wt% of Ni, 0.2wt% to 2wt% of Si, 2wt% to 10wt% of Mo, 0.3wt% to 0.4wt% of Nb, 0.2wt% to 0.4wt% of Mn, and the balance of Fe;

The wear-resistant filler comprises 10 to 40wt% of TiN, 10 to 30wt% of CeO ₂ and 30 to 80wt% of nickel-coated graphite;

wherein the nickel-coated graphite comprises 10wt% to 40wt% of C and 60wt% to 90wt% of Ni.

2. The ductile iron component damage repairing method based on the ultra-high speed laser cladding technology is characterized by comprising the following steps of:

Three-dimensional modeling is carried out on the damaged area of the ductile cast iron component, and slicing treatment is carried out on the constructed model so as to obtain solid slice layer data;

placing the alloy powder for repairing the damage of the ductile iron component according to claim 1 in a carrier gas type powder feeding cylinder, and aligning a coaxial annular ultra-high speed cladding head to the damage area;

And starting a powder feeding system, taking laser as a heat source, and controlling the coaxial annular ultra-high speed cladding head to execute an ultra-high speed laser repairing process according to the layer data of the solid sheet until the damaged area is filled up so as to obtain the nodular cast iron repairing piece.

3. The ductile iron component damage repair method according to claim 2 wherein the coaxial annular ultra-high speed cladding head is at a distance of 5.5mm to 6.5mm from the surface of the damaged area.

4. The ductile iron component damage repair method according to claim 2, further comprising:

argon with the flow of 8L/min to 15L/min is introduced into the coaxial annular ultra-high speed cladding head as protective gas;

wherein, the powder feeding air flow of the powder feeding system is 4L/min to 9L/min.

5. The method for repairing the damage of the ductile iron component according to claim 2, wherein in the ultra-high speed laser cladding technology, the spot diameter is 1mm to 5mm, the laser power is 1500W to 2400W, the scanning speed is 900mm/min to 1200mm/min, the powder feeding speed is 0.3r/min to 1r/min, the lap rate is 45% to 75%, the molten pool width is 3mm to 5mm, and the molten pool height is 0.2mm to 1.2mm.

6. The ductile iron component damage repair method according to claim 2, further comprising, before performing a super-high speed laser repair process on the damaged area:

Polishing the damaged area, and cleaning the polished damaged area by using a cleaning agent.

7. The ductile iron component damage repair method according to claim 2, wherein controlling the coaxial annular ultra-high speed cladding head to perform an ultra-high speed laser repair process according to the solid slice layer data until the damaged area is filled to obtain a ductile iron repair, comprises:

Controlling the coaxial annular ultra-high speed cladding head to execute an ultra-high speed laser repairing process according to the solid slice layer data until the damaged area is filled up so as to obtain an intermediate repairing piece;

and standing the intermediate restoration, cooling to room temperature by air, and polishing the surface of the intermediate restoration to obtain the ductile cast iron restoration.

8. The ductile iron component damage repair method according to any one of claims 2 to 7 wherein the repair path of the ultra-high speed laser repair process is a reciprocating type.