阅读说明：本技术 一种用于钢轨铣削刀片的涂层 (Coating for steel rail milling blade ) 是由 杭仁莆 李詠侠 邹丹 刘艳军 谢元彦 陈超 于 2021-01-07 设计创作，主要内容包括：本发明公开了一种用于钢轨铣削刀片的涂层,所述涂层为多层TiAlCrN复合涂层。本发明提供的一种用于钢轨铣削刀片的涂层,通过改变涂层的成分和结构,多层TiAlCrN复合涂层的优势,结合了两种涂层的优势在保持涂层硬度与耐磨性的同时增加的涂层的润滑性减少了磨擦系数,提高了涂层的韧性和结合力,减少了崩裂和剥落；减小了涂层与钢轨间的亲和力和摩擦系数,降低了切削温度,有效地提高了涂层刀片的寿命。(The invention discloses a coating for a steel rail milling blade, which is a multilayer TiAlCrN composite coating. According to the coating for the steel rail milling blade, the components and the structure of the coating are changed, and the advantages of the multilayer TiAlCrN composite coating are combined, so that the hardness and the wear resistance of the coating are kept, the lubricity of the coating is increased, the friction coefficient is reduced, the toughness and the binding force of the coating are improved, and the cracking and the peeling are reduced; the affinity and the friction coefficient between the coating and the steel rail are reduced, the cutting temperature is reduced, and the service life of the coated blade is effectively prolonged.)

1. A coating for a steel rail milling blade is characterized in that the coating is a multilayer TiAlCrN composite coating.

2. The coating for the steel rail milling blade according to claim 1, wherein the content of each component in the multilayer TiAlCrN composite coating is respectively 40-50% of N, 10-15% of Cr, 30-35% of Al and 20-25% of Ti.

3. A coating for a rail milling insert according to claim 1, wherein the multi-layer TiAlCrN composite coating comprises a CrN coating and an AlTiN coating and is formed in an alternating stack.

4. A coating for a rail milling insert according to claim 1, wherein the thickness of each layer in the multilayer TiAlCrN composite coating is 10-1000 nm.

5. A coating for a rail milling insert according to claim 1 wherein the multilayer TiAlCrN composite coating further comprises silicon, boron, carbon and compounds thereof.

6. The coating for the steel rail milling insert as claimed in claim 1, wherein the standard surface hardness of the multilayer TiAlCrN composite coating is 2500-.

7. A coating for a rail milling insert according to claim 1, wherein the number of the TiAlCrN composite coating layers is 4-40, and the total thickness is 2.2-22 μm.

8. A rail milling insert characterized in that the rail milling insert surface is coated with a coating according to any one of claims 1 to 6.

9. A rail milling insert according to claim 7, wherein the rail milling insert is a flat milling insert, a radius insert, a fat edge insert or a finish milling insert.

10. A rail milling insert according to claim 7 wherein the substrate of the rail milling insert is cemented carbide with a cobalt content of 6-15% and a WC grain size of 0.2-0.8 μm.

Technical Field

The invention relates to the technical field of cutter coatings, in particular to a coating for a steel rail milling blade.

Background

The rail injuries such as fatigue cracks, corrugation, stripping and chipping, side abrasion, crushing and the like are aggravated by the high speed and heavy load of the railway, the running safety of the train is endangered, the operation and maintenance cost of the railway is increased, and the casualties and huge economic losses caused by train derailment due to the sudden damage of wheel rails are caused every year. It is not economical to secure the operation safety of the train by merely replacing the damaged rail, and the repair of the rail needs to be more emphasized. A rail milling and grinding vehicle is necessary maintenance equipment for high-speed rail and subway rails, and a rail milling blade is a core component of the rail milling and grinding vehicle.

The coating composition used in the steel rail milling field at present is mainly used for increasing the surface hardness and improving the abrasive resistance of the blade, thereby achieving the purpose of prolonging the service life of the blade, and the coating composition is a single-layer structure coating of Ti, Al and N.

The rail material U71Mn has high hardness and good toughness, and needs a large cutting force during milling, so that the cutter and the rail generate strong extrusion and friction. The toughness and the binding force of the existing coating are insufficient, and the main failure modes are cracking and peeling.

According to the blade user's perception begin to collect blade service behavior and scrap the blade and carry out the analysis in fact to the blade, discover can produce a large amount of sparks and processing equipment does not have cooling system and make the blade can be processed under very big temperature difference change repeatedly in the course of working, in addition try to improve before the coating hardness life-span does not obviously promote, consequently the technical scheme of whole coating just changes from increasing the wearability and switches to on increasing the heat dissipation and preventing the blade from long-pending bits.

Therefore, in view of the current research on rail milling insert coatings, how to provide a coating for a rail milling insert that can reduce friction and improve the lifetime of the coated insert is a problem that needs to be solved by those skilled in the art.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a coating for a steel rail milling blade, which uses CrN coating components with good heat dissipation, strong adhesion resistance and good toughness to form a multilayer composite coating with AlTiN, and combines the advantages of the two coatings by changing the components and the structure of the coating and the advantages of the multilayer TiAlCrN composite coating, so that the lubricating property of the coating is improved while the hardness and the wear resistance of the coating are maintained, the friction coefficient is reduced, the toughness and the bonding force of the coating are improved, and the chipping and the peeling are reduced; the affinity and the friction coefficient between the coating and the steel rail are reduced, the cutting temperature is reduced, and the service life of the coated blade is effectively prolonged.

In order to achieve the purpose, the invention adopts the following technical scheme:

a coating for a steel rail milling blade is a multilayer TiAlCrN composite coating.

Preferably, the content of each component in the multilayer TiAlCrN composite coating is respectively 40-50% of N, 10-15% of Cr, 30-35% of Al and 20-25% of Ti.

Preferably, the multilayer TiAlCrN composite coating comprises a CrN coating and an AlTiN coating, and is formed by alternately stacking.

Preferably, in the multilayer TiAlCrN composite coating, the thickness of each layer is 10-1000 nanometers.

Preferably, the multilayer TiAlCrN composite coating further comprises silicon, boron, carbon and compounds thereof.

Preferably, the standard surface hardness of the multilayer TiAlCrN composite coating is 2500-.

The technical effect of adopting the technical scheme is as follows: the CrN coating and the AlTiN coating are stacked in a multi-layer structure, the standard surface hardness of the coating is 2500-4500Hv which is slightly lower than that of the AlTiN single-layer coating but higher than that of the CrN single-layer coating, and the heat dissipation and the adhesion resistance of the coating can be greatly improved.

Preferably, the number of the layers of the multilayer TiAlCrN composite coating is 4-40, and the total thickness is 2.2-22 μm.

The invention also provides a steel rail milling blade, and the surface of the steel rail milling blade is coated with the coating.

Preferably, the rail milling blade is a flat milling blade, a circular arc blade, a fat edge blade or a finish milling blade.

Preferably, the steel rail cutting blade substrate is made of hard alloy with 6-15% of cobalt and 0.2-0.8 μm of WC grain size.

Compared with the prior art, the invention discloses the coating for the steel rail milling blade, which has the following technical effects: the coating for the steel rail milling blade provided by the invention uses CrN coating components with good heat dissipation, strong adhesion resistance and good toughness to form a multilayer composite coating with AlTiN, and the advantages of the multilayer TiAlCrN composite coating are combined with the advantages of the two coatings by changing the components and the structure of the coating, so that the hardness and the wear resistance of the coating are kept, the lubricity of the coating is increased, the friction coefficient is reduced, the toughness and the bonding force of the coating are improved, and the chipping and the peeling are reduced; the affinity and the friction coefficient between the coating and the steel rail are reduced, the cutting temperature is reduced, and the service life of the coated blade is effectively prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic view showing a coating layer for a rail milling insert according to embodiment 1 of the present invention.

FIG. 2 is a drawing showing a coating structure of a coated blade according to example 1 of the present invention.

FIG. 3 is a drawing showing a structure of a conventional coating layer of a blade according to the present invention

Fig. 4 is a graph showing the results of wear tests on an orbital milling tool having a coating according to the present invention and an orbital milling tool having a conventional coating.

Fig. 5 is a graph showing the results of wear tests on an orbital milling tool having a coating according to the present invention and five commercially available coatings.

FIG. 6 is a drawing showing the cutting condition of a coated insert according to example 1 of the present invention.

FIG. 7 is a drawing showing the cutting of a conventional coated insert according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention provides a coating for a steel rail milling blade, which is a multilayer TiAlCrN composite coating shown in figure 1.

In order to further optimize the technical scheme, the contents of all components in the multilayer TiAlCrN composite coating are respectively 40-50% of N, 10-15% of Cr, 30-35% of Al and 20-25% of Ti.

In order to further optimize the technical scheme, the multilayer TiAlCrN composite coating comprises a CrN coating and an AlTiN coating, and is formed by alternately stacking.

In order to further optimize the technical scheme, the thickness of each layer in the multilayer TiAlCrN composite coating is 10-1000 nanometers.

In order to further optimize the technical scheme, the multilayer TiAlCrN composite coating further comprises silicon, boron, carbon and compounds thereof.

In order to further optimize the technical scheme, the standard surface hardness of the multilayer TiAlCrN composite coating is 2500-.

In order to further optimize the technical scheme, the number of the layers of the multilayer TiAlCrN composite coating is 4-40, and the total thickness is 2.2-22 μm.

The embodiment of the invention also provides the steel rail milling blade, and the surface of the steel rail milling blade is coated with the coating.

In order to further optimize the technical scheme, the steel rail milling blade is a flat milling blade, an arc blade, a fat edge blade or a finish milling blade.

In order to further optimize the technical scheme, the hard alloy with the cobalt content of 10% and the WC grain size of 0.6 mu m is used as the base material of the blade.

Example 1

The embodiment provides a coating for a steel rail milling blade, which is a multilayer TiAlCrN composite coating, the multilayer TiAlCrN composite coating comprises a CrN coating and an AlTiN coating, and the CrN coating and the AlTiN coating are alternately stacked, the coating structure is 11 layers, the thickness of each layer is 320 nanometers, the total thickness of the coating is 3.5 mu m, and the component ratio is as follows: 40-50% of N, 10-15% of Cr, 30-35% of Al and 20-25% of Ti.

The coating is used for a flat milling blade, a circular arc blade, a fat edge blade and a finish milling blade, the blade base material adopts the material with the brand number ST20F of the company, and the coating adopts the multilayer TiAlCrN composite coating.

To further illustrate the technical effects of the present invention, the present invention also performed the related performance tests on the conventional coating and the coating of example 1

Blade wear test

A. Material to be processed

Name (R)

Manufacturer of the product

Material brand

Type (kg/m)

Rail size (mm)

Steel rail length (m)

HRC

Rail for railway vehicle

Climbing steel

U71Mn

60

176*150*73*16.5

0.8

28-31

B. Processing parameters

Machine tool model	Huazhi MV510 processing center	Main shaft rotation speed n	573r/min
				Cutting mode	Face milling	Cutting speed vc	180m/min
Type of tool	Indexable flat milling cutter	Depth of cut ap	0.15mm
				Diameter of cutter head	100mm (blade X5)	Feed rate per tooth fz	0.8mm/r
Cooling method	Dry milling	Total feed rate F	2.292m/min

The results of the tests are shown in fig. 4, and it can be seen that the wear amount of the coated insert of the present invention is smaller than that of the conventional coating, and in addition, the wear test is performed on five types of commercially available coatings in comparison with the coating of example 1, and as a result, fig. 5 shows that the data in the graph shows that example 1 has a smaller wear amount than the other five types of coatings.

In conclusion, by changing the components and the structure of the coating, the advantages of the multilayer TiAlCrN composite coating are combined with the advantages of the two coatings, the hardness and the wear resistance of the coating are kept, and the lubricating property of the coating is increased, so that the friction coefficient is reduced.

(II) Shanghai subway line fault rail test

Contrast data of actual service life of Shanghai subway line fault rail

The inserts with the surfaces coated with the coatings provided by the example 1 and the comparative example 1 are put into practical use, the inserts coated with the coatings provided by the example 1 are provided in 2019, only 5 inserts are used for crushing and cannot be used continuously by China high and new equipment, Inc. on the No. 11 line of Shanghai subway in a distance exceeding 2000 kilometers by using accumulated milling, about 200 inserts using the coatings provided by the comparative example 1 cannot be used due to crushing, and the service life of the inserts is greatly prolonged by the multi-layer TiAlCrN composite coating disclosed by the invention.

Therefore, the composition and the structure of the coating are changed, the advantages of the multilayer TiAlCrN composite coating are combined, the hardness and the wear resistance of the coating are kept, the lubricity of the coating is increased, the friction coefficient is reduced, the toughness and the binding force of the coating are improved, and the chipping and the peeling are reduced; the affinity and the friction coefficient between the coating and the steel rail are reduced, the cutting temperature is reduced, and the service life of the coated blade is effectively prolonged.

As can be seen from comparison between the graph 6 and the graph 7, the obvious sparks are not generated during milling operation of the blade using the coating scheme, and the sparks are splashed during milling operation of the blade with the traditional coating, so that the temperature of the blade with the coating can be greatly reduced during processing, and the problem of failure of peeling and cracking of the coating during milling operation of a steel rail is solved.

According to the technical scheme, other components can be added into the coating components, including but not limited to silicon, boron, carbon and the like, or the component proportion of the coating is changed, or the structure, the number of layers or the thickness of the coating is changed, so that similar or same effects are achieved.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.