Multilayered coating on a cutting device

Abstract

There is provided a cutting device comprising a base comprising bainite, and a multilayered coating present on the base, wherein said multilayered coating comprises several periods comprising at least two coating layers, of which at least one comprises chromium. Layers of pure chromium, chromium carbide or chromium nitride may be present. The coated cutting device has an excellent wear resistance and stay sharp properties. There is also provided a method for manufacturing such the cutting device, comprising the steps of providing a base comprising bainite and / or martensite, and forming a multilayered coating on the surface using PVD.

Description

[0001] Multilayered coating on a cutting device

[0002] Field of the invention

[0003] The present invention relates to a multilayered coating on a base , more speci fically to a cutting device coated with a multi-layered coating, and a method of manufacturing such a device .

[0004] Background

[0005] Many processes that have been used for decades do no longer ful fill new standards or is currently being phased out due to their negative impact on health and / or environment . For example , use of hard chrome coating by the electroplating process , previously commonly used for coating of e . g . cutting devices , is banned by the European union .

[0006] It is critical for the industry to continuously improve and replace or limit the use of environmentally problematic substances . In some cases , the suggested replacements require new processing conditions , which may be devastating for the material properties . This could lead to loss in product functionalities . It is therefore of high importance to develop new sustainable materials , combinations and methods , which maintain a products functionality .

[0007] In addition to environmental benefits , improvement in ef ficiency and / or material properties may have a positive ef fect on the quality of the resulting products and lower production costs . Summary

[0008] One obj ect of the present invention is to obviate at least some of the disadvantages in the prior art .

[0009] In a first aspect there is provided a cutting device comprising a base comprising bainite , and a multilayered coating present on at least a part of the base , wherein said multilayered coating comprises 3- 100 periods , wherein each period comprises at least two coating layers , wherein at least one coating layer in each period comprises chromium ( Cr ) .

[0010] The coated cutting device has an excellent wear resistance and stay sharp properties , and may be manufactured using environmentally friendly methods .

[0011] In a second aspect there is provided a method for manufacturing such a cutting device , comprising the steps of providing a base comprising bainite , and forming a multilayered coating on the surface of at least a part of the base by applying a plurality of coating layers onto the base using PVD, in an order such that 3- 100 periods are created upon the surface , wherein each period comprises at least two coating layers , wherein at least one coating layer in each period comprises chromium ( Cr ) .

[0012] Further embodiments of the present invention are defined in the appended dependent claims , which are explicitly incorporated herein .

[0013] Brief description of the drawings

[0014] Aspects and embodiments will be described with reference to the following drawings in which : Figure 1 shows a base of a cutting device according to the invention with a cutting edge , having a coating structure thereon .

[0015] Figure 2 shows a cross-section of a cutting device according to the invention, with a base and a multilayered coating structure comprising repeating three coating layers periods .

[0016] Figure 3 shows a cross-section of a cutting device according to the invention, with a base and a multilayered coating structure comprising repeating two coating layers periods .

[0017] Detailed description

[0018] Before the invention is disclosed and described in detail , it is to be understood that this invention is not limited to particular configurations , process steps and materials disclosed herein as such configurations , process steps and materials may vary somewhat . It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present invention is limited only by the appended claims and equivalents thereof .

[0019] It must be noted that , as used in this speci fication and the appended claims , the singular forms "a" , "an" and "the" include plural referents unless the context clearly dictates otherwise .

[0020] The use of the terms such as " includes" , "has , " "comprises" or the like should be generally understood as open-ended and non-limiting unless speci fically stated otherwise . These terms include the limiting concept "consists of" .

[0021] Steel has a base of iron, and is usually alloyed with carbon and other elements . Martensite and bainite are two di f ferent microstructures that can form in low alloyed carbon steel during certain heat treatments . Thus i f it is referred to bainite and / or martensite , it is implicit that it concerns a steel alloy .

[0022] The microstructures are created as steel is first heated to a temperature within the austenitising range , usually 790- 915 ° C, followed by quenching, usually in a bath . It is held for a time to allow trans formation to a martensite or bainite microstructure , and then cooled to room temperature .

[0023] Martensite is formed in steels by rapid cooling ( quenching) from the austenite phase to bypass the formation of other phases like pearlite or bainite . The martensitic trans formation begins when the austenite reaches the martensite start temperature (Ms) . As the steel is cooled, more austenite trans forms to martensite until the lower trans formation temperature (Mf ) is reached .

[0024] Bainite generally forms at temperatures higher than the martensite start temperature . For both bainite and martensite , the quenching rate needs to be fast enough to avoid unwanted microstructures such as pearlite . The heat treatment process is usually referred to as austempering, and the isothermal temperature used for the trans formation is usually referred to as the austempering temperature . Bainite may for example be formed around 125-550 ° C, typically around 250-400 ° C, depending on the speci fic steel composition and desired properties . It is the Martensite start temperature that defines the lower bainitic trans formation temperature . Often there is a small overlap where the bainite may continue to form below the martensite start temperature . However, the trans formation temperatures also depend on the alloying elements and austenite grain si ze . Most alloying elements will slow the formation of bainite , especially carbon .

[0025] Martensite is a hard and brittle microstructure with a crystal structure called body-centered tetragonal (BCT ) . It is characteri zed by a highly stressed lattice structure , which gives it its hardness . However, its brittleness can make it prone to cracking or failure under certain conditions . Therefore , post-heat treatment processes like tempering are often employed .

[0026] Bainite has a plate-like two-phase microstructure consisting of ferrite and cementite . Compared to martensite , bainite has a lower hardness but higher toughness . Its strength and ductility makes it suitable for applications where both properties are desired . Unlike martensitic steels , alloys based on bainite often do not need tempering after trans formation in order to optimise strength and toughness . One of the main concerns with tempering is decrease in hardness .

[0027] The speci fic formation and properties of martensite and bainite can be influenced by factors such as the composition of the steel , the cooling rate during heat treatment , and the temperature at which the trans formation occurs .

[0028] The K-S (Kurdj umov-Sachs ) orientation relationship ( OR) describes the crystallographic relationship between the austenite phase and the bainite or martensite phase in steel . It speci fies the preferred crystallographic orientations of the two phases during the phase trans formation . The K-S OR involves the FCC ( face-centered cubic ) structure of austenite and the BCT (body-centered tetragonal ) or BCC (body-centered cubic ) structures of bainite / martensite . The K-S orientation relationship for bainite / martensite indicates how the BCT or BCC structure of bainite / martensite is related to the FCC structure of austenite .

[0029] The BCT structure of bainite / martensite arises due to the tetragonality in the lattice resulting from the distortion caused by carbon enrichment . When carbon has time to di f fuse in bainite , it will have a BCC structure instead of BCT , depending on the speci fic alloying elements , especially carbon and the trans formation conditions . Nevertheless , both BCC and BCT structures of bainite / martensite are related to the FCC structure of austenite through the K-S orientation relationship .

[0030] For K-S there are twenty- four di f ferent crystallographic relationships . Each of these can be referred to as a variant (V1-V24 ) , where each variant corresponds to a packet in the bainitic microstructure . Variants tend to have preferred neighbouring variant , which is referred to as variant pairing . Variant pairing, within this disclosure , refers to such variant pairing . There is also a relationship between the FCC and BCT or BCC structure called Bain Correspondence . The variants are grouped based on their Bain correspondence , which can be divided into three groups , called Bain groups 1-3 . The variants within the same Bain group are separated with small misorientation .

[0031] The definitions of the terminology herein is intended to be interpreted according to the disclosure of " Thermal Stabili ty and Mechani cal Properti es of Baini ti c Steel" , PhD thesis , KTH Royal Institute of Technology, 2022 , Adam Stahlkrantz , ISBN 978- 91- 8040-401-3 .

[0032] Physical Vapor Deposition ( PVD) is a thin film deposition technique used to coat surfaces with various materials . It involves the deposition of a vapori zed material onto a substrate to create a thin layer .

[0033] In the context of the multilayered coating of the invention, a " layer" refers to an individual thin film or coating that is applied sequentially onto the base 2 material . The layers can vary in thickness , composition, and functionality, providing di f ferent properties and functionalities to the multi-layered coating . The combination of multiple layers in the coating structure allows for the optimi zation of properties such as durability .

[0034] In a first aspect there is provided a cutting device 1 comprising a base 2 comprising at least one selected from the group consisting of bainite and martensite , and a multilayered coating 3 present on at least a part of the base 2 . The base 2 may for example consist of or substantially consist of bainite and / or martensite . In other words, the base 2 is coated with a multilayered coating which comprises multiple coating layers 5. The multilayered coating 3 comprises 3-100 periods 4. Each period 4 comprises at least two coating layers 5. The concept of periods 4 is introduced to describe a more or less repeating structure of the multilayered coating 3. At least one coating layer 5 in each period 4 comprises chromium (Cr) . In other words, there are 3-100 layers comprising chromium in the multilayered coating 3, each such layer being adjacent to at least one layer with a differing composition.

[0035] In one embodiment, the multilayered coating 3 comprises 5- 90 periods, 15-85 periods 4, such as 30-70 periods 4, 35- 55 periods 4 or 40-60 periods 4.

[0036] The multilayered structure provides excellent durability, wear resistance and stay sharp properties. Alternating softer and harder layers produce good stay sharp properties. The multilayered structure may be configured such that there is a gradient of hardness throughout the structure. The hardness may be varied for example by an increased occurrence of hard layers or an increase in the thickness of hard layers in a segment. The gradient may be such that a hardness of the coating is increased towards the outer surface.

[0037] In one embodiment, each period 4 comprises at least one of a layer comprising pure chromium (Cr) , a layer comprising chromium nitride Cr-N and a layer comprising chromium carbide Cr-C. In one embodiment, each period 4 comprises a layer comprising pure chromium Cr. In one embodiment, each period 4 comprises a layer 5 of chromium carbide Cr-C. In one embodiment , each period 4 comprises a layer 5 of chromium nitride Cr-N . In one embodiment , each period 4 comprises at least one of a layer comprising chromium nitride Cr-N and a layer comprising chromium carbide Cr-C . In one embodiment , each period 4 comprises a layer comprising pure chromium ( Cr ) and at least one of a layer comprising chromium nitride Cr-N and a layer comprising chromium carbide Cr-C . In one embodiment , each period 4 comprises a layer comprising pure chromium Cr, a coating layer 5 of chromium nitride Cr-N and a coating layer 5 of chromium carbide Cr-C . The order within the periods may vary or be similar .

[0038] Many di f ferent combination of varying coating layers 5 comprising Cr, Cr-N or Cr-C are thus conceivable . A layer 5 comprising chromium nitride Cr-N may additionally comprise chromium carbide Cr-C and / or pure chromium Cr and such a layer 5 comprising chromium carbide Cr-C may additionally comprise chromium nitride Cr-N and / or pure chromium Cr . Comprising may also mean that the layer is only consisting of that element .

[0039] In one embodiment , each period 4 comprises a layer comprising chromium ( Cr ) and a layer comprising chromium carbide Cr-C . The multilayered structure may in other words comprise a repeating structure of alternating layers comprising chromium ( Cr ) and chromium carbide Cr-C .

[0040] In one embodiment , each period 4 comprises a layer comprising chromium ( Cr ) and a layer comprising chromium nitride Cr-N . The multilayered structure may in other words comprise a repeating structure of alternating layers comprising chromium ( Cr ) and chromium nitride Cr-N . In one embodiment, each period 4 comprises a layer comprising chromium (Cr) , a layer comprising chromium nitride Cr-N, and a layer comprising chromium carbide Cr- C. The multilayered structure may in other words comprise a repeating structure of alternating layers comprising chromium, chromium nitride Cr-N, and chromium carbide Cr-C in different orders.

[0041] In Cr-N, the stoichiometry may be selected so that the chromium nitride is one of the stable phases of chromium nitride, for example Cr2N or CrN.

[0042] In Cr-C, the stoichiometry may be selected so that the chromium and carbon form one of the stable phases, for example Cr23Ce, Cr?C3 or CrsC2.

[0043] Additional coating layers 5 may be present in the coating 3, such as an initial coating layer between the base 2 and the multilayered coating 3, and / or a top layer on the outermost coating layer 5 of the multilayered coating 3, and / or an intermediate layer somewhere within the multilayered coating 3. Several layers may be added under, in or on the multilayered coating 3, such that even if there is a relatively low number of periods 4 in the multilayered coating 3 as defined herein, there may be a total number of layers providing a multilayered coating structure comprising a relatively high number of layers, such as more than 3, 5, 35, 50, 70, 90, 110, 150 or 300 layers .

[0044] Elements such as titanium (Ti) , Aluminium (Al) , Wolfram (W) , or Zirconium (Zr) may be present in the multilayered coating 3. The layers of differing composition that are also included in the periods may for example comprise or consist of Ti, Al, W, Zr. Examples of compositions in coating layers 5 are also, TiN, CrAlN, ZrN, and CN. A period may for example comprise Cr and Ti, CrN and Al, CrC and W, or Cr and Zr.

[0045] In one embodiment, there is an initial coating layer that can be more ductile (i.e. flexible, malleable or tensile) , for good adhesion and distribution of forces and stresses, in order to avoid delamination of the coating. Such a layer may comprise or consist of Chromium. In one embodiment, there is a top layer of a low friction coating that may contain for example Mo, W or C, e.g. diamond like carbon (DLC) , being present for low friction towards the wood .

[0046] Figure 1 shows a base 2 of a cutting device 1 according to the invention with a cutting edge having a coating structure thereon. The cutting device 1 is in the act of cutting a material.

[0047] Figure 2 shows a cross-section of a cutting device 1 according to the invention, with a base 2 and a multilayered coating 3 structure thereon. The multilayered coating 3 comprises repeating three coating layer 5 periods 4. Three full such periods 4 are shows in Figure 2. Figure 3 shows a similar cross-section, where multilayered coating 3 comprises repeating two coating layer 5 periods 4, with five full such periods 4 shown in Figure 3.

[0048] In one embodiment, the layers are applied using physical vapour deposition (PVD) . Advantages of using PVD are described below. In one embodiment, each of the coating layers 5 has a thickness of 1-100 pm. The thickness may be 1-15 pm. The thickness of the layers may vary.

[0049] The base 2 may comprise (or consist of) bainite or martensite or both.

[0050] The characteristics of martensite and bainite makes them suitable for enduring the coating process without deteriorating and for providing a suitably hard base 2 for the multilayered coating 3.

[0051] Bainite and Martensite can be hardened in to a hardness that when used as a base 2 in combination with the multilayered coating 3, which includes hard layers, results in good wear properties and allows the durability and toughness needed for a cutting device, including the possibility to resharpen. A soft base may be difficult to file sharp and may result in bad adhesion or cracking of the coating. A harder base may be too hard to file with hand tools. The base 2 of this invention gives a well- balanced level of hardness, brittleness, toughness and durability .

[0052] In one embodiment, the base 2 comprises carbon in the range of 0.1 to 1.2 wt%, such as 0.5 to 0.8 wt%. An increase in carbon content increases the hardness of bainite and martensite, and slightly improves the tempering resistance at shorter tempering times. A decreasing Ms temperature with increasing carbon content also allows the steels to undergo bainitic transformation towards lower temperatures without interference of martensite. However, increased carbon content also results in longer austempering times to reach a fully bainitic structure, especially at lower austempering temperatures. In one embodiment, the base comprises 0 to 0.4 wt% silicon (Si) . This may provide good adhesion properties.

[0053] In one embodiment, the base 2 comprises bainite and the bainite comprises 5-20 vol% of cementite, such as 7-15 vol%, such as around 9 vol%.

[0054] In one embodiment, the base 2 comprises bainite and the most prevalent variant paring in the bainite is V1-V6, giving desirable durability properties. In one embodiment, the base 2 comprises bainite and the most prevalent Bain group in the bainite is Bain group 3, giving desirable durability properties. The microstructure of the bainite when transformed remains stable up to at least 375 °C even then exposed to the temperature for up to at least 24h.

[0055] In one embodiment, the cutting device 1 is a device selected from the group consisting of: a cutterlink for a chainsaw chain, a cutting blade for a saw, a blade for a clearing saw, a cutting equipment for a lawn mower or automower, a knife, scissors, and a secateur.

[0056] In one embodiment, the cutting device 1 is a cutter link for a chainsaw chain, and said cutter link is operatively coupled to a drive link for a chainsaw chain and a tie strap for a chainsaw chain. In one embodiment, at least one of said drive link and tie strap comprise bainite in which the most prevalent variant paring is V1-V6. In one embodiment, variant paring V1-V6 is most prevalent in all three parts (cutter link, drive link and tie strap) . In one embodiment, at least one of the drive link and tie strap comprises bainite in which the most prevalent Bain group is Bain group 3 . In one embodiment , Bain group 3 is most prevalent in all three parts .

[0057] In one embodiment , the cutting device 1 is operatively coupled to a rivet . The rivet may have a body comprising bainite . In one embodiment , the most prevalent variant pairing in said body is V1-V4 or V1-V6 . For the rivet , a lower hardness is required and by curing the steel to a V1-V4 pairing with a lower hardness , a tempering step may be avoided . The body may be at least partly surrounded by a layer comprising martensite in which the most prevalent variant pairing is V1-V2 , giving a desirable hardness of the surface . In one embodiment , the most prevalent Bain group in such a rivet body is Bain group 1 or 3 , and the most prevalent Bain group in the martensite in the surrounding layer is Bain group 2 .

[0058] In a second aspect there is provided a method for manufacturing a cutting device 1 according to any of the embodiments described herein, comprising the steps of :

[0059] - providing a base 2 comprising at least one selected from the group consisting of bainite and martensite , and

[0060] - forming a multilayered coating 3 on the surface of at least a part of the base 2 by applying a plurality of coating layers 5 onto the base 2 , preferably using PVD, in an order such that 3- 100 periods 4 are created upon the surface , wherein each period 4 comprises at least two coating layers 5 , wherein at least one coating layer 5 in each period 4 comprises chromium ( Cr ) .

[0061] Physical vapor depositions ( PVD) coating process is widely used both for functional and decorative applications . It is an environmental friendly, low temperature , and scalable process that provides good control over coating thickness distribution. PVD coatings can be fine tuned to have desired wear properties. Masking of cutterlinks to have coating only on specific areas is a challenge, which is easily achievable in PVD processes.

[0062] The layers may be applied in an order such that any version of the multilayered coating 3 of the cutting device 1 is created. In one embodiment of the method, the layers are applied such that each period 4 comprises a layer comprising at least one selected from the group consisting of pure chromium, chromium nitride and chromium carbide .

[0063] In one embodiment of the method, step a) comprises cooling a steel from austenization temperature of the steel to a temperature in the range of 125 to 350 °C, such as 230 to 10 °C, such as around 250 to 300 °C. In one embodiment, the steel is kept at a temperature within this range for 10 minutes to 24 hours, such as for 30 to 90 minutes. The cooling is performed at a rate adapted to form bainite, i.e. sufficient to avoid unwanted high temperature transformations to pearlite.

[0064] In one embodiment of the method, step a) comprises cooling a steel from austenization temperature of the steel to a temperature within the range of from the martensite start temperature (Ms) of the steel to 335 °C. The martensite start temperature may for example be around 125 °C. In one embodiment, the steel is kept at a temperature within this range for 10 minutes to 24 hours, such as for 30 to 90 minutes. The temperature range may for example be from the Ms of the steel to 325 °C, 315 °C, 305 °C or 295 °C. V1-V6 has been shown the most predominate variant pairing for bainite transformed within the range from the martensite start temperature to about 325 ° C . The cooling is performed at a rate suf ficient to avoid unwanted high temperature trans formations such as pearlite , in order to form bainite . The Ms is suitably determined using dilatometry .

[0065] In one embodiment of the method, the method further comprises a step of tempering the base 2 at a temperature from 200 to 350 ° C before applying the coating . The tempering may for example be performed for up to l Oh, such as up to 5h, up to 2h or up to Ih .

[0066] During tempering of martensite , the material is reheated to increase the ductility, typically to a temperature in the range of bainitic austempering range , and held at that temperature for a speci fic duration . This controlled heating and cooling process allows for the reduction of internal stresses . Tempering will allow any retained austenite to trans form into more stable microstructures . It will also allow for precipitation of carbides within the material ' s matrix . The exact temperature and duration of tempering depend on the desired material properties .

[0067] For example , low-temperature tempering results in increased hardness but lower toughness , while high- temperature tempering can enhance toughness but reduce hardness .

[0068] Chemical cleaning, plasma treatment and / or other surface treatments may be performed before applying the coating to increase the coating adhesion while retaining the bulk properties . In one embodiment of the method, the method comprises a step of plasma treatment before , during or after applying forming the multilayered coating 3 . The above mentioned rivet may be provided by cooling a steel comprising austenite to a temperature of above 340 ° C, such as in the range of 375 to 460 ° C, at a cooling rate suf ficient to avoid unwanted high temperature trans formations to pearlite and instead form bainite . This promotes the formation of the V1-V4 pairing .

[0069] There is also provided a cutting device 1 obtained according to the method described herein .

Claims

Claims1. A cutting device (1) comprising- a base (2) comprising bainite, and- a multilayered coating (3) present on at least a part of the base (2) , wherein said multilayered coating (3) comprises 3-100 periods ( 4 ) , wherein each period (4) comprises at least two coating layers (5) , wherein at least one coating layer (5) in each period(4) comprises chromium (Cr) .

2. The cutting device (1) according to claim 1, wherein said multilayered coating (3) comprises 5-85, such as 30-70 or 40-60, periods (4) .

3. The cutting device (1) according to any of claims 1-2, wherein each period comprises a coating layer comprising pure chromium (Cr) .

4. The cutting device (1) according to any of claims 1-3, wherein each period comprises at least one of a coating layer comprising chromium nitride (Cr-N) and a coating layer comprising chromium carbide (Cr-C) .

5. The cutting device (1) according to any of claims 1-4, comprising at least one of an initial adhesive coating layer between the base (2) and the multilayered coating (3) and a top layer of a low friction coating on the outermost layer of the multilayered coating (3) .

6. The cutting device (1) according to any of claims 1-5, wherein the multilayered coating (3) has a hardness gradient such that a hardness of the multilayered coating (3) is increased towards the outer surface of the coating (3) .

7. The cutting device (1) according to any of claims 1-6, wherein the multilayered coating (3) comprises at least one layer comprising Ti, Al, W, or Zr.

8. The cutting device (1) according to any of claims 1-7, wherein the coating layers (5) are applied using physical vapour deposition (PVD) .

9. The cutting device (1) according to any of claims 1-8, wherein each of the coating layers (5) has a thickness of 1-100 pm, preferably of 1-15 pm.

10. The cutting device (1) according to any of claims1-9, wherein the base (2) comprises carbon in the range of 0.1 to 1.2 wt% of the weight of the base.

11. The cutting device (1) according to any of claims 1-10, wherein the base comprises 0 to 0.4 wt% silicon (Si) .

12. The cutting device (1) according to any of claims 1-11, wherein the base (2) comprises bainite comprising 5-20 vol% of cementite.

13. The cutting device (1) according to any of claims 1-12, wherein the base (2) comprises bainite and the most prevalent variant paring in the bainite is VI- V6 .

14. The cutting device (1) according to any of claims 1-13, wherein the base (2) comprises bainite and the most prevalent Bain group in the bainite is Bain group 3.

15. The cutting device (1) according to any of claims 1-14, wherein said cutting device (1) is a device selected from the group consisting of: a cutterlink for a chainsaw chain, a cutting blade for a saw, a blade for a clearing saw, a cutting equipment for a lawn mower or automower, a knife, scissors, and a secateur .

16. The cutting device (1) according to any of claims 1-15, wherein said cutting device (1) is a cutter link for a chainsaw chain, wherein said cutter link is operatively coupled to a drive link for a chainsaw chain and a tie strap for a chainsaw chain, wherein at least one of said drive link and tie strap each comprise bainite in which the most prevalent variant paring is V1-V6 and / or in which the most prevalent Bain group is Bain group 3.

17. The cutting device (1) according to any of claims 1-16, wherein said cutting device (1) is operatively coupled to a rivet, wherein said rivet has a body comprising bainite in which the most prevalent variant pairing is V1-V4 or V1-V6 and / or in which the most prevalent Bain group is Bain group 1 or Bain group 3, and wherein said body is at least partly surrounded by a layer comprising martensite in which the most prevalent variant pairing is V1-V2 and / or the most prevalent Bain group is Bain group 2.

18. A method for manufacturing a cutting device (1) according to any of claims 1-17 comprising the steps of : a. providing a base (2) comprising bainite, b. forming a multilayered coating (3) on the surface of at least a part of the base (2) by applying a plurality of coating layers (5) onto the base (2) in an order such that 3-100 periods (4) are created upon the surface of the base (2) , wherein each period (4) comprises at least two coating layers (5) , wherein at least one coating layer (5) in each period (4) comprises chromium (Cr) .

19. The method according to claim 18, wherein the layers are applied using PVD.

20. The method according to any of claims 18-19, wherein the layers are applied such that each period(4) comprises at least one coating layer comprising pure chromium.

21. The method according to any of claims 18-20, wherein the layers are applied such that each period (4) comprises at least one of a coating layer (5) comprising chromium nitride and a coating layer (5) comprising chromium carbide.

22. The method according to any of claims 18-20, wherein step a) comprises cooling a steel comprising austenite to a temperature within the range of from the martensite start temperature of the steel to 335 or23. The method according to claim 22, wherein the steel is kept within that temperature range for 10 minutes to 24 hours, such as for 30 to 90 minutes.

24. The method according to any of claims 18-23, further comprising a step of tempering after step a and before step b.

25. The method according to any of claims 18-24, further comprising a step of plasma treatment before, during or after applying the multilayered coating (3) .

26. A cutting device (1) obtained according to the method of any of claims 18-25.

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