CN113293367A - Method for improving thermal fatigue performance of brake disc - Google Patents
Method for improving thermal fatigue performance of brake disc Download PDFInfo
- Publication number
- CN113293367A CN113293367A CN202110407315.8A CN202110407315A CN113293367A CN 113293367 A CN113293367 A CN 113293367A CN 202110407315 A CN202110407315 A CN 202110407315A CN 113293367 A CN113293367 A CN 113293367A
- Authority
- CN
- China
- Prior art keywords
- brake disc
- thermal fatigue
- laser
- fatigue performance
- improving
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 90
- 238000004372 laser cladding Methods 0.000 claims abstract description 40
- 238000005253 cladding Methods 0.000 claims abstract description 25
- 239000002131 composite material Substances 0.000 claims abstract description 25
- 230000008569 process Effects 0.000 claims description 51
- 239000000843 powder Substances 0.000 claims description 49
- 230000035939 shock Effects 0.000 claims description 22
- 238000001816 cooling Methods 0.000 claims description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 20
- 238000005498 polishing Methods 0.000 claims description 16
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 16
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 14
- 150000002910 rare earth metals Chemical class 0.000 claims description 14
- 238000000227 grinding Methods 0.000 claims description 13
- 239000000126 substance Substances 0.000 claims description 11
- 230000003746 surface roughness Effects 0.000 claims description 11
- 238000010521 absorption reaction Methods 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 8
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical group [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 8
- 229910052782 aluminium Inorganic materials 0.000 claims description 8
- 238000000137 annealing Methods 0.000 claims description 8
- 238000004140 cleaning Methods 0.000 claims description 8
- 239000011888 foil Substances 0.000 claims description 8
- 238000005554 pickling Methods 0.000 claims description 8
- 229910052786 argon Inorganic materials 0.000 claims description 7
- 239000000835 fiber Substances 0.000 claims description 7
- 239000011521 glass Substances 0.000 claims description 7
- 238000009413 insulation Methods 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 7
- 239000007787 solid Substances 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims 1
- 239000000463 material Substances 0.000 abstract description 12
- 239000011248 coating agent Substances 0.000 abstract description 6
- 238000000576 coating method Methods 0.000 abstract description 6
- 230000002787 reinforcement Effects 0.000 abstract description 4
- 230000004048 modification Effects 0.000 abstract description 3
- 238000012986 modification Methods 0.000 abstract description 3
- 229910000734 martensite Inorganic materials 0.000 abstract description 2
- 239000011159 matrix material Substances 0.000 abstract description 2
- 239000000758 substrate Substances 0.000 abstract 1
- 230000009466 transformation Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 30
- 238000009661 fatigue test Methods 0.000 description 25
- 238000010438 heat treatment Methods 0.000 description 21
- 238000005728 strengthening Methods 0.000 description 15
- 238000005520 cutting process Methods 0.000 description 8
- 230000007547 defect Effects 0.000 description 8
- 238000013461 design Methods 0.000 description 8
- 238000012545 processing Methods 0.000 description 8
- 230000035882 stress Effects 0.000 description 8
- 239000000498 cooling water Substances 0.000 description 7
- 238000002474 experimental method Methods 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000002635 electroconvulsive therapy Methods 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000005422 blasting Methods 0.000 description 2
- -1 compound rare earth Chemical class 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 238000007709 nanocrystallization Methods 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005255 carburizing Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000010892 electric spark Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C24/00—Coating starting from inorganic powder
- C23C24/08—Coating starting from inorganic powder by application of heat or pressure and heat
- C23C24/10—Coating starting from inorganic powder by application of heat or pressure and heat with intermediate formation of a liquid phase in the layer
- C23C24/103—Coating with metallic material, i.e. metals or metal alloys, optionally comprising hard particles, e.g. oxides, carbides or nitrides
- C23C24/106—Coating with metal alloys or metal elements only
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B27/00—Other grinding machines or devices
- B24B27/033—Other grinding machines or devices for grinding a surface for cleaning purposes, e.g. for descaling or for grinding off flaws in the surface
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D10/00—Modifying the physical properties by methods other than heat treatment or deformation
- C21D10/005—Modifying the physical properties by methods other than heat treatment or deformation by laser shock processing
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
Abstract
The invention belongs to the field of material surface modification, relates to a method for improving the thermal fatigue performance of a brake disc, and particularly relates to a method for improving the bonding strength of a brake disc surface coating and a matrix and the thermal fatigue performance of the brake disc through coordination and reinforcement of laser cladding and laser impact composite treatment. On one hand, the laser impact can refine and clad Fe-based coating grains, prefabricate residual compressive stress and improve the bonding performance between a cladding layer and a substrate, and on the other hand, the coating structure can generate martensite phase transformation at high temperature, the energy is dissipated, and the thermal fatigue performance of the brake disc is improved. Through the implementation of the invention, the thermal fatigue performance of the brake disc can be effectively improved, the economic loss caused by the thermal fatigue failure of the brake disc can be reduced, and the running safety of the railway vehicle can be obviously improved.
Description
Technical Field
The invention belongs to the field of material surface modification, relates to a method for improving the thermal fatigue performance of a brake disc, and particularly relates to a method for improving the bonding strength of a brake disc surface coating and a matrix and the thermal fatigue performance of the brake disc through coordination and reinforcement of laser cladding and laser impact composite treatment.
Background
Brake discs are the most important part of a rail vehicle for safe operation and brake loading. When the speed per hour of the train reaches 400km/h, on the premise that the braking distance is less than 3700m, the instantaneous temperature of the brake disc is more than 800 ℃, the combined action of severe alternating thermal stress and alternating load needs to be borne, the thermal fatigue damage is generated on the friction surface of the brake disc after long-term service, the train brake failure is caused, and the potential danger is huge. Under the background of the continuous increase of the number of high-speed rails and the continuous extension of the design service life of the high-speed rails all over the world, how to meet the requirement that a brake disc has excellent thermal fatigue performance so as to improve the safety and the stability of the high-speed rail operation is a problem to be solved urgently.
Since thermal fatigue damage is usually only present on the surface of the brake disc, it is expensive if the entire brake disc is scrapped, and the axle is easily damaged by detaching the brake disc, which causes inconvenience. The high-performance heat-resistant material layer is prepared on the surface of the brake disc, so that the thermal fatigue performance of the brake disc can be improved, and the cost can be greatly saved. Therefore, more and more research is focused on the problem of strengthening the friction surface of the brake disc. In recent years, a laser cladding method which can provide an efficient, automatic, clean and pollution-free production environment and process for industrial manufacturing can be completely exposed in industrial application. Compared with the traditional material surface strengthening methods such as electric spark machining, physical and chemical vapor deposition, surfacing, friction welding, spraying and the like, the method has the unique advantages that the material is almost not limited, the repairing area and the base material are in metallurgical bonding, the dilution rate is low, the shape of the repairing area is not limited, the automation is easy to realize, and the like. However, under the influence of heat transmission and stress strain in the laser cladding process, columnar crystals with coarse grains, intermetallic compounds with high brittleness and high residual stress are easily formed at the joint of the cladding layer and the base material, and the columnar crystals, the intermetallic compounds with high brittleness and the high residual stress are easily used as crack sources in the thermal fatigue process, even the cladding layer falls off, and the improvement effect of the cladding layer on the thermal fatigue performance of the brake disc is seriously influenced.
The laser shock is to induce super strong shock wave to make the surface layer of the material generate plastic deformation and deep residual compressive stress field by utilizing the interaction of high-energy short pulse laser on the surface of the material and the absorption layer prefabricated on the surface of the material. Compared with the traditional carburizing (nitrogen) and shot blasting processes, the laser impact method has the advantages of no need of medium recovery, high controllability, small influence on the surface roughness of the material, lower requirement on the working environment, capability of generating residual compressive stress which is more than 10 times of the effect of common shot blasting, and capability of realizing the nanocrystallization of the surface structure of the material. Therefore, if the laser impact method can be applied to the strengthening treatment of the laser cladding surface strengthened brake disc, the microstructure of the friction surface of the brake disc is regulated and controlled by laser impact to be thinned or even nanocrystallized, and a proper residual stress field is reserved, so that the purpose of simultaneously improving the heat resistance and the toughness of the cladding layer to improve the thermal fatigue life of the brake disc is achieved, the probability of failure caused by thermal fatigue damage of the brake disc is effectively reduced, and the running safety of a railway vehicle is improved.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a process method for enhancing the laser cladding layer of a brake disc by adopting a laser impact method so as to improve the thermal fatigue property of the brake disc.
The main reason for the thermal fatigue failure of the brake disc is the formation of thermal fatigue cracks, the process is that regional hot spots are generated on the friction surface of the brake disc, then the regional hot spots are developed into the cracks which are distributed in a net shape and are mostly less than 0.2mm in depth, and the cracks are further developed into deeper radial cracks. The traditional repairing method usually adopts a grinding and polishing method, so that the brake disc is thinner and thinner (belonging to a 'reducing processing' mode). When the thickness is reduced by more than 2mm, the whole brake disc is scrapped, the repair and disassembly processes are complex and easy to damage the axle every time, and the maintenance cost of the brake disc is too high. This patent proposes to adopt the laser shock's method to carry out strengthening treatment to the laser cladding layer of brake disc, adjusts and controls brake disc friction surface microstructure through laser shock and makes it refine and even nanocrystallization to reserve appropriate residual stress field, reach the purpose that improves cladding layer heat resistance, obdurability simultaneously in order to improve the thermal fatigue life of brake disc, effectively improve the thermal fatigue performance of brake disc, improve rail vehicle operation's security.
The present invention achieves the above-described object by the following technical means.
The invention discloses a process method for improving the thermal fatigue property of a brake disc, which comprises the steps of carrying out laser cladding treatment on the surface of a component, then carrying out laser shock treatment on the component, greatly improving the thermal fatigue property of the component after the coordination and reinforcement of the component and the component, prolonging the service life of the component and expanding the application field of the component. The method comprises the following specific steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) Preparing cladding powder:
the Fe-based powder comprises, by mass, 24-26% of Mn, 3.5-4.5% of Si, 4.5-5.5% of Ni, 0.08-0.12% of composite rare earth, 0.08-0.12% of C, and the balance Fe, and has a particle size of 100-240 meshes. Wherein, the chemical components of the composite rare earth are as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe.
After the Fe-based powder is prepared in proportion, grinding and mixing the Fe-based powder in a vacuum ball mill for 5-10 min to ensure that the powder is spherical or nearly spherical; and then preserving the heat for 10-20 min in a vacuum insulation box at the temperature of 50-60 ℃ to remove the influence of water.
Among the preferred compositions of the Fe-based powder mentioned above are: the chemical components by mass percent are that Mn is 25%, Si is 4%, Ni is 5%, composite rare earth is 0.1%, C is 0.1%, and the balance is Fe.
(3) The laser cladding process comprises the following steps:
and (3) carrying out laser cladding treatment on the surface of the brake disc by using a fiber laser in an argon protection atmosphere in a coaxial powder feeding mode, and preheating the cleaned brake disc at the temperature of 250-300 ℃. The laser cladding process parameters are as follows: laser power: 1600W; scanning speed: 400 mm/min; the diameter of the light spot is 3 mm; the lap joint rate: 40 percent.
The powder feeding speed has an important influence on the thickness of a cladding layer, and the selection of the thickness (y, unit: um) and the powder feeding speed (x, unit: g/min) of the cladding layer is calculated according to the following model in order to ensure the subsequent laser shock treatment effect:
wherein the thickness y of the cladding layer is less than 1200 um;
(4) and (5) annealing treatment. Keeping the temperature at 1000-1100 ℃ for 12h, and cooling along with the furnace.
(5) And (4) polishing, namely polishing away surface oxide skin to smooth the surface of the brake disc, wherein the roughness reaches Ra 0.5 um.
(6) And (3) laser shock processing.
A high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, and an absorption layer is an aluminum foil with the thickness of 0.3 mm. The laser shock process parameters are as follows: the diameter of the light spot: 3.0 mm; the lap joint rate: 50 percent; pulse width: 20 ns; wavelength: 1064 nm.
The brake disc surface roughness has an important influence on the brake disc thermal fatigue performance, and in order to ensure that the brake disc surface roughness (Z) is less than Ra 0.35um after laser impact, the laser energy (a) is selected according to the following model:
among them, the laser energy is preferably 5J.
The invention has the beneficial effects that:
in view of the fact that cracks usually only appear on the surface of the brake disc, the method is different from a traditional 'reduction processing' mode, the method adopts laser cladding and laser impact, belongs to an additive manufacturing mode, on one hand, the laser impact can refine and clad Fe-based coating grains, prefabricate residual compressive stress and improve the bonding performance between a cladding layer and a base body, and on the other hand, the coating structure can generate martensite phase change at high temperature, dissipate energy and improve the thermal fatigue performance of the brake disc. Through the implementation of the invention, the thermal fatigue performance of the brake disc can be effectively improved, the economic loss caused by the thermal fatigue failure of the brake disc can be reduced, and the running safety of the railway vehicle can be obviously improved.
Drawings
FIG. 1 is a thermal fatigue test specimen cut on a composite reinforced surface of a brake disc by means of wire cutting according to the present invention.
Detailed Description
The invention relates to a process method for improving the thermal fatigue performance of a brake disc, which comprises the following steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) Preparing cladding powder:
the Fe-based powder comprises, by mass, 24-26% of Mn, 3.5-4.5% of Si, 4.5-5.5% of Ni, 0.08-0.12% of composite rare earth, 0.08-0.12% of C, and the balance Fe, and has a particle size of 100-240 meshes. Wherein, the chemical components of the composite rare earth are as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe. Before the laser cladding process, the powder needs to be ground and mixed in a vacuum ball mill for 5-10 min, so as to ensure that the powder is spherical or nearly spherical; and then preserving the heat for 10-20 min in a vacuum insulation box at the temperature of 50-60 ℃ to remove the influence of moisture.
(3) And (3) laser cladding process. And carrying out laser cladding treatment on the surface of the brake disc by using a fiber laser in a coaxial powder feeding mode under the argon protection atmosphere. The cleaned brake disc is subjected to preheating treatment at the temperature of 250-300 ℃. Laser cladding process parameters: the laser power is 1600W, the scanning speed is 400mm/min, the spot diameter is 3mm, and the lap joint rate is 40%. In order to ensure the subsequent laser shock treatment effect and ensure that the thickness (y, unit: um) of the cladding layer is less than 1200um, the selection of the powder feeding speed (x, unit: g/min) is calculated according to the following model:
(4) and (4) carrying out annealing treatment, keeping the temperature at 1000 ℃ for 12h, and then cooling along with the furnace.
(5) And (4) polishing, namely polishing away surface oxide skin to enable the surface of the brake disc to be smooth, wherein the roughness of the brake disc reaches Ra 0.5 um.
(6) And (3) laser shock processing. A high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, and an absorption layer is an aluminum foil with the thickness of 0.3 mm. Laser shock process parameters: the diameter of the light spot is 3.0mm, the lapping rate is 50%, the pulse width is 20ns, and the wavelength is 1064 nm. To ensure that the brake disk surface roughness (Z) is less than Ra 0.35um after laser impact, the laser energy (a) should be selected according to the following model:
and finally, performing a thermal fatigue test on the brake disc subjected to the laser cladding and laser shock composite strengthening treatment. A thermal fatigue test piece as shown in FIG. 1 was cut on the composite reinforced surface of the brake disc by means of wire cutting. The samples used in the thermal fatigue test are firstly mechanically polished and then observed under an Optical Microscope (OM), and the samples without defects such as cracks, air holes and the like in the gap area are selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design, the temperature is kept for 120s after the highest temperature is reached, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. One cycle of heating and cooling was completed each time, and the number of cycles was recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance.
Example 1
The brake disc is made of 40CrNiMo, and the strengthening process is carried out according to the following steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) And preparing cladding powder. The Fe-based powder comprises the chemical components of, by mass, 24% of Mn, 3.5% of Si, 4.5% of Ni, 0.08% of composite rare earth, 0.08% of C and the balance Fe, and the particle size of the powder is 100-240 meshes. Wherein, the chemical components of the composite rare earth are as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe. Before the laser cladding process, grinding and mixing the powder in a vacuum ball mill for 5-10 min to ensure that the powder is spherical or nearly spherical; and then preserving the heat for 10-20 min in a vacuum insulation box at the temperature of 50-60 ℃ to remove the influence of water.
(3) And (3) laser cladding process. And carrying out laser cladding treatment on the surface of the brake disc by using a fiber laser in a coaxial powder feeding mode under the argon protection atmosphere. The cleaned brake disc is subjected to preheating treatment at the temperature of 250-300 ℃. Laser cladding process parameters: the laser power is 1600W, the scanning speed is 400mm/min, the spot diameter is 3mm, the lap joint rate is 40%, the powder feeding speed is 7.1g/min, and the thickness of the cladding layer is 651.3 um.
(4) And (4) carrying out annealing treatment, keeping the temperature at 1000 ℃ for 12h, and then cooling along with the furnace.
(5) And (4) polishing, namely polishing away surface oxide skin to enable the surface of the brake disc to be smooth, wherein the roughness of the brake disc reaches Ra 0.5 um.
(6) And (3) laser shock processing. A high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, and an absorption layer is an aluminum foil with the thickness of 0.3 mm. Laser shock process parameters: the diameter of a light spot is 3.0mm, the lapping rate is 50%, the pulse width is 20ns, the wavelength is 1064nm, the laser energy is 4J, and the surface roughness of the brake disc is 0.18 um.
And finally, performing a thermal fatigue test on the brake disc subjected to the laser cladding and laser shock composite strengthening treatment. A thermal fatigue test piece as shown in FIG. 1 was cut on the composite reinforced surface of the brake disc by means of wire cutting. The samples used in the thermal fatigue test are firstly mechanically polished and then observed under an Optical Microscope (OM), and the samples without defects such as cracks, air holes and the like in the gap area are selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design, the temperature is kept for 120s after the highest temperature is reached, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. One cycle of heating and cooling was completed each time, and the number of cycles was recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance, as shown in Table 1.
Example 2
The brake disc is made of 40CrNiMo, and the strengthening process is carried out according to the following steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) And preparing cladding powder. The Fe-based powder comprises, by mass, 26% of Mn, 4.5% of Si, 5.5% of Ni, 0.12% of composite rare earth, 0.12% of C and the balance Fe, and has a particle size of 100-240 meshes. Wherein, the chemical components of the composite rare earth are as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe. Before the laser cladding process, grinding and mixing the powder in a vacuum ball mill for 5-10 min to ensure that the powder is spherical or nearly spherical; and then preserving the heat for 10-20 min in a vacuum insulation box at the temperature of 50-60 ℃ to remove the influence of water.
(3) And (3) laser cladding process. And carrying out laser cladding treatment on the surface of the brake disc by using a fiber laser in a coaxial powder feeding mode under the argon protection atmosphere. The cleaned brake disc is subjected to preheating treatment at the temperature of 250-300 ℃. Laser cladding process parameters: the laser power is 1600W, the scanning speed is 400mm/min, the spot diameter is 3mm, the lap joint rate is 40%, the powder feeding speed is 11.8g/min, and the thickness of the cladding layer is 1150.5 um.
(4) And (4) carrying out annealing treatment, keeping the temperature at 1000 ℃ for 12h, and then cooling along with the furnace.
(5) And (4) polishing, namely polishing away surface oxide skin to enable the surface of the brake disc to be smooth, wherein the roughness of the brake disc reaches Ra 0.5 um.
(6) And (3) laser shock processing. A high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, and an absorption layer is an aluminum foil with the thickness of 0.3 mm. Laser shock process parameters: the diameter of a light spot is 3.0mm, the lapping rate is 50%, the pulse width is 20ns, the wavelength is 1064nm, the laser energy is 6J, and the surface roughness of the brake disc is 0.34 um.
And finally, performing a thermal fatigue test on the brake disc subjected to the laser cladding and laser shock composite strengthening treatment. A thermal fatigue test piece as shown in FIG. 1 was cut on the composite reinforced surface of the brake disc by means of wire cutting. The samples used in the thermal fatigue test are firstly mechanically polished and then observed under an Optical Microscope (OM), and the samples without defects such as cracks, air holes and the like in the gap area are selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design, the temperature is kept for 120s after the highest temperature is reached, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. One cycle of heating and cooling was completed each time, and the number of cycles was recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance, as shown in Table 1.
Example 3
The brake disc is made of 40CrNiMo, and the strengthening process is carried out according to the following steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) And preparing cladding powder. The Fe-based powder comprises, by mass, 25% of Mn, 4% of Si, 5% of Ni, 0.1% of composite rare earth, 0.1% of C and the balance Fe, and has a particle size of 100-240 meshes. Wherein, the chemical components of the compound rare earth are as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe. Before the laser cladding process, the powder needs to be ground and mixed in a vacuum ball mill for 5-10 min, so as to ensure that the powder is spherical or nearly spherical; and then preserving the heat for 10-20 min in a vacuum insulation box at the temperature of 50-60 ℃ to remove the influence of water.
(3) And (3) laser cladding process. And carrying out laser cladding treatment on the surface of the brake disc by using a fiber laser in a coaxial powder feeding mode under the argon protection atmosphere. The cleaned brake disc is subjected to preheating treatment at the temperature of 250-300 ℃. Laser cladding process parameters: the laser power is 1600W, the scanning speed is 400mm/min, the spot diameter is 3mm, the lap joint rate is 40%, the powder feeding speed is 9.4g/min, and the thickness of the cladding layer is 948.5 um.
(4) And (4) carrying out annealing treatment, keeping the temperature at 1000 ℃ for 12h, and then cooling along with the furnace.
(5) And (4) polishing, namely polishing away surface oxide skin to enable the surface of the brake disc to be smooth, wherein the roughness of the brake disc reaches Ra 0.5 um.
(6) And (3) laser shock processing. A high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, and an absorption layer is an aluminum foil with the thickness of 0.3 mm. Laser shock process parameters: the diameter of a light spot is 3.0mm, the lapping rate is 50%, the pulse width is 20ns, the wavelength is 1064nm, the laser energy is 5J, and the surface roughness of the brake disc is 0.265 um.
And finally, performing a thermal fatigue test on the brake disc subjected to the laser cladding and laser shock composite strengthening treatment. A thermal fatigue test piece as shown in FIG. 1 was cut on the composite reinforced surface of the brake disc by means of wire cutting. The samples used in the thermal fatigue test are firstly mechanically polished and then observed under an Optical Microscope (OM), and the samples without defects such as cracks, air holes and the like in the gap area are selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design, the temperature is kept for 120s after the highest temperature is reached, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. One cycle of heating and cooling was completed each time, and the number of cycles was recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance, as shown in Table 1.
Comparative example 1
The brake disc is made of 40CrNiMo, and a thermal fatigue sample shown in figure 1 is cut on the brake surface of the brake disc in a linear cutting mode. The test sample used in the thermal fatigue test is firstly mechanically polished, then observed under an Optical Microscope (OM), and the test sample without defects such as cracks, air holes and the like in a gap area is selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design, the temperature is kept for 120s after the highest temperature is reached, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. One cycle of heating and cooling was completed each time, and the number of cycles was recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance, as shown in Table 1.
Comparative example 2
The brake disc is made of 40CrNiMo, and the strengthening process is carried out according to the following steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) And preparing cladding powder. The Fe-based powder comprises, by mass, 25% of Mn, 4% of Si, 5% of Ni, 0.1% of composite rare earth, 0.1% of C and the balance Fe, and has a particle size of 100-240 meshes. Wherein, the chemical components of the compound rare earth are as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe. Before the laser cladding process, the powder needs to be ground and mixed in a vacuum ball mill for 5-10 min, so as to ensure that the powder is spherical or nearly spherical; and then preserving the heat for 10-20 min in a vacuum insulation box at the temperature of 50-60 ℃ to remove the influence of water.
(3) And (3) laser cladding process. And carrying out laser cladding treatment on the surface of the brake disc by using a fiber laser in a coaxial powder feeding mode under the argon protection atmosphere. The cleaned brake disc is subjected to preheating treatment at the temperature of 250-300 ℃. Laser cladding process parameters: the laser power is 1600W, the scanning speed is 400mm/min, the spot diameter is 3mm, the lap joint rate is 40%, the powder feeding speed is 9.4g/min, and the thickness of the cladding layer is 948.5 um.
(4) And (4) carrying out annealing treatment, keeping the temperature at 1000 ℃ for 12h, and then cooling along with the furnace.
(5) And (4) polishing, namely polishing away surface oxide skin to enable the surface of the brake disc to be smooth, wherein the roughness of the brake disc reaches Ra 0.5 um.
A thermal fatigue test specimen as shown in FIG. 1 was cut on the reinforcing surface of the brake disc by wire cutting. A sample used in the thermal fatigue test needs to be mechanically polished, then observed under an Optical Microscope (OM), and a sample without defects such as cracks, air holes and the like in a gap area is selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design time, the temperature is kept for 120s after reaching the highest temperature, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. Heating and cooling are respectively carried out once to complete one cycle, and the cycle number is recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance, as shown in Table 1.
Comparative example 3
The brake disc is made of 40CrNiMo, and the strengthening process is carried out according to the following steps:
(1) and cleaning the surface of the brake disc by adopting a mechanical grinding or acid pickling method.
(2) And (3) laser shock processing. A high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, and an absorption layer is an aluminum foil with the thickness of 0.3 mm. Laser shock process parameters: the diameter of a light spot is 3.0mm, the lapping rate is 50%, the pulse width is 20ns, the wavelength is 1064nm, the laser energy is 5J, and the surface roughness of the brake disc is 0.265 um.
A thermal fatigue test specimen as shown in FIG. 1 was cut on the reinforcing surface of the brake disc by wire cutting. A sample used in the thermal fatigue test needs to be mechanically polished, then observed under an Optical Microscope (OM), and a sample without defects such as cracks, air holes and the like in a gap area is selected for the thermal fatigue test. Thermal fatigue experiments were performed on a LRP1200 model cold thermal fatigue tester. The experimental conditions are room temperature and atmospheric environment. The circulating temperature is from room temperature to 400 ℃ and from room temperature to 600 ℃. The heating process is controlled by design time, the temperature is kept for 120s after reaching the highest temperature, the temperature of the heating furnace is corrected by a potentiometer, and the error range of the measured temperature is +/-2 ℃; the cooling process uses circulating cooling water, the depth of the sample entering water is (20 +/-1) mm, and the time in water is 20 s. Heating and cooling are respectively carried out once to complete one cycle, and the cycle number is recorded as 1. The cycle count was terminated at a crack growth length of 0.1mm, and the number of cycles at this time was expressed as the corresponding thermal fatigue performance, as shown in Table 1.
As can be seen from table 1: the embodiment is that the brake disc of the high-speed rail currently uses more cast steel materials. After the reinforcement of the process disclosed by the invention, the thermal fatigue performance of the brake disc is greatly improved, and especially the improvement of the thermal fatigue performance at 600 ℃ is favorable for promoting the brake disc to be applied to the high-speed rail working condition environment with higher speed per hour.
In a word, the laser cladding and laser impact composite strengthening treatment process method provided by the invention can obviously improve the thermal fatigue performance of the brake disc.
TABLE 1 thermal fatigue Properties of brake discs prepared by different strengthening Processes
The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.
Claims (9)
1. A method for improving the thermal fatigue performance of a brake disc is characterized by comprising the following steps:
(1) cleaning the surface of the brake disc by adopting a mechanical polishing or acid pickling method;
(2) preparing cladding powder:
the Fe-based powder comprises the chemical components of, by mass, 24-26% of Mn, 3.5-4.5% of Si, 4.5-5.5% of Ni, 0.08-0.12% of composite rare earth, 0.08-0.12% of C and the balance Fe, and has a particle size of 100-240 meshes;
after the Fe-based powder is prepared in proportion, grinding and mixing the Fe-based powder in a vacuum ball mill for 5-10 min to ensure that the powder is spherical or nearly spherical; then, preserving the heat in a vacuum insulation box at the temperature of 50-60 ℃ for 10-20 min to remove the water;
(3) the laser cladding process comprises the following steps:
performing laser cladding treatment on the surface of the brake disc by using a fiber laser in an argon protective atmosphere in a coaxial powder feeding mode, and preheating the cleaned brake disc;
the selection of the thickness y of the cladding layer and the powder feeding speed x should be calculated according to the following model:
where, y, cladding layer thickness, unit: um;
x, powder feeding speed, unit: g/min;
(4) annealing treatment;
(5) polishing, namely polishing away surface oxide skin to enable the surface of the brake disc to be smooth;
(6) the laser shock process comprises the following steps:
a high-energy lamp pump solid laser system is adopted, a restraint layer is K9 glass, an absorption layer is aluminum foil, and laser impact is carried out; the surface roughness Z of the brake disc after laser impact and the laser energy a should be selected according to the following model:
wherein, Z, brake disc surface roughness after laser impact, unit: um;
a, laser energy, unit J.
2. The method for improving the thermal fatigue performance of a brake disc according to claim 1, wherein in the step (2), the chemical composition of the Fe-based powder comprises, by mass, 25% of Mn, 4% of Si, 5% of Ni, 0.1% of the rare earth complex, 0.1% of C, and the balance of Fe.
3. The method for improving the thermal fatigue performance of the brake disc as claimed in claim 1 or 2, wherein in the step (2), the chemical composition of the composite rare earth is as follows: 45-55% of Ce, 25-35% of La, 10-15% of Nd, 4-8% of Pr, 5-8% of Ti, 1-2% of B and the balance of Fe.
4. The method for improving the thermal fatigue performance of the brake disc as claimed in claim 1, wherein in the step (3), the temperature of the preheating treatment is 250-300 ℃; the laser cladding process parameters are as follows: laser power: 1600W; scanning speed: 400 mm/min; the diameter of the light spot is 3 mm; the lap joint rate: 40 percent.
5. The method for improving the thermal fatigue performance of a brake disc according to claim 1, wherein in step (3), the cladding thickness y is less than 1200 um.
6. The method for improving the thermal fatigue performance of the brake disc as claimed in claim 1, wherein in the step (4), the annealing treatment comprises the following specific steps: keeping the temperature at 1000-1100 ℃ for 12h, and cooling along with the furnace.
7. The method for improving the thermal fatigue performance of a brake disc according to claim 1, wherein in the step (5), the roughness after grinding is required to reach Ra 0.5 um.
8. The method for improving the thermal fatigue performance of a brake disc according to claim 1, wherein in the step (6), the thickness of the aluminum foil is 0.3 mm; the laser shock process parameters are as follows: the diameter of the light spot: 3.0 mm; the lap joint rate: 50 percent; pulse width: 20 ns; wavelength: 1064 nm.
9. The method for improving the thermal fatigue performance of a brake disc according to claim 1, wherein in step (6), the laser energy is preferably 5J, and the surface roughness Z of the brake disc after laser impact is less than Ra 0.35 um.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110407315.8A CN113293367A (en) | 2021-04-15 | 2021-04-15 | Method for improving thermal fatigue performance of brake disc |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110407315.8A CN113293367A (en) | 2021-04-15 | 2021-04-15 | Method for improving thermal fatigue performance of brake disc |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113293367A true CN113293367A (en) | 2021-08-24 |
Family
ID=77319857
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110407315.8A Pending CN113293367A (en) | 2021-04-15 | 2021-04-15 | Method for improving thermal fatigue performance of brake disc |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113293367A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114381728A (en) * | 2021-12-06 | 2022-04-22 | 中车株洲电机有限公司 | Laser cladding repair method for shaft parts |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103409758A (en) * | 2013-07-12 | 2013-11-27 | 江苏大学 | Method for prolonging life of pump shells and blades by carrying out laser strengthening micro-cracks |
-
2021
- 2021-04-15 CN CN202110407315.8A patent/CN113293367A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103409758A (en) * | 2013-07-12 | 2013-11-27 | 江苏大学 | Method for prolonging life of pump shells and blades by carrying out laser strengthening micro-cracks |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114381728A (en) * | 2021-12-06 | 2022-04-22 | 中车株洲电机有限公司 | Laser cladding repair method for shaft parts |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110129674B (en) | Gradient material steel rail frog prepared by laser cladding | |
| CN101519778B (en) | Laser cladding method for strengthening surface of piercing point | |
| CN101403114B (en) | Surface crack renovation method for key elements of chain grate | |
| CN105177569A (en) | Laser repairing method for ductile iron surface | |
| CN110465657B (en) | Shape-controlled deposition method for laser additive manufacturing of alloy steel | |
| CN105108444B (en) | The reparation of high-temperature service shearing equipment cutter and intensifying method | |
| CN102529217B (en) | Method for preparing copper/molybdenum composite board with molybdenum fibers by accumulative roll bonding | |
| CN106222650A (en) | The surface reinforcing method of laser-impact graphite oxide ene coatings | |
| CN102031466B (en) | TiN coating silicon carbide fiber reinforced titanium-based composite material and preparation method thereof | |
| CN113293367A (en) | Method for improving thermal fatigue performance of brake disc | |
| KR20190041729A (en) | Hardfacing method of press die | |
| CN104805450A (en) | Three-phase Al-Ti-Cu microparticle enhanced Al alloy protective coating and preparation method | |
| CN110042339A (en) | A kind of vacuum carburization method for the speedup that cools down | |
| CN101956198A (en) | Surface composite strengthening technology for precipitation hardening stainless steel and precipitation hardening stainless steel material | |
| CN109468638A (en) | A kind of preparation method of diamond enhancing high-entropy alloy composite coating | |
| CN100346963C (en) | Metal/ceramic laminated composite material prevention plate | |
| CN109536949B (en) | Process method for improving thermal fatigue property of aluminum alloy material | |
| CN112899678B (en) | Axle remanufacturing method, remanufactured axle and system | |
| CN112974844A (en) | Gradient alloy steel powder for laser additive manufacturing of brake disc of high-speed rail and preparation method | |
| CN113186483A (en) | Amorphous functional protective coating suitable for complex working conditions and preparation method thereof | |
| CN116833222A (en) | Titanium/aluminum composite material with high interface bonding strength and rolling composite forming method | |
| CN110340344B (en) | Method for improving utilization rate of laser additive manufacturing alloy steel powder | |
| CN101215623B (en) | Surface seasoning treatment method for increasing timang cutting processability | |
| CN111041475B (en) | Method for preparing reinforced coating by laser alloying/polishing composite integration | |
| CN211311566U (en) | Device based on titanium alloy surface laser nitriding and shot blasting synchronous compounding technology |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210824 |