JP4720993B2 - Surface coated high speed tool steel cutting tool with excellent chipping resistance in high speed heavy cutting of difficult-to-cut materials - Google Patents

Description

  In the present invention, the hard coating layer has excellent lubricity. Therefore, even when it is used for high-speed heavy cutting of highly viscous difficult-to-cut materials such as mild steel, stainless steel, and high manganese steel, it is cut during cutting. The present invention relates to a cutting tool made of a surface-coated high-speed tool steel (hereinafter referred to as a coated high-speed tool) that exhibits excellent chipping resistance without welding powder to the cutting edge.

  In general, for coated cutting tools, throwaway inserts that are used detachably attached to the tip of a cutting tool for turning and planing of various steels and cast irons, drilling of the work material Drills and miniature drills used in, etc., as well as solid type end mills used for chamfering, grooving, shouldering, etc. of the work material, and the solid type by attaching the throwaway tip detachably A slow-away end mill tool that performs a cutting process in the same manner as an end mill is known.

Further, as a coated cutting tool, for example, a single phase is formed on the surface of a cemented carbide substrate made of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet. Having a structure, and
Composition formula: (Ti _{1− (X + Y)} Al _X V _Y ) N (wherein X is 0.50 to 0.65, Y is 0.01 to 0.09 in atomic ratio),
Coated carbide tool formed by vapor-depositing a hard coating layer composed of a composite nitride of Ti, Al, and V [hereinafter referred to as (Ti, Al, V) N] satisfying the above conditions with an average layer thickness of 2 to 8 μm The (Ti, Al, V) N layer has the characteristics that high temperature hardness and heat resistance are obtained by Al as a constituent component, high temperature strength is obtained by Ti, and lubricity is improved by V. It is also known that

Furthermore, the above-mentioned coated carbide tool is, for example, the above-mentioned carbide substrate is inserted into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. For example, an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which a Ti—Al—V alloy having a predetermined composition is set, for example, at a current of 90 A, while being heated to a temperature of 500 ° C. At the same time, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of, for example, 2 Pa. On the other hand, the carbide substrate is applied to the surface of the carbide substrate under a condition that a bias voltage of, for example, −100 V is applied. It is also known that it is manufactured by vapor-depositing a hard coating layer composed of the (Ti, Al, V) N layer.
Japanese Patent Laid-Open No. 10-237628

  In recent years, the performance of cutting devices has been remarkably improved. On the other hand, there are strong demands for labor saving and energy saving and further cost reduction for cutting, and accordingly, cutting tends to increase in speed. And in the above-mentioned conventional coated carbide tool provided with a hard coating layer composed of (Ti, Al, V) N layer, this can be cut with carbon steel, low alloy steel, and ordinary cast iron under high-speed cutting conditions. When used to perform, there is no problem showing normal cutting performance, but especially high-viscosity heavy heat generation with high heat generation is required for cutting difficult-to-cut materials such as mild steel, stainless steel, and high manganese steel. When used under cutting conditions, chipping easily occurs on the cutting edge due to insufficient lubricity of the hard coating layer, which causes chipping (small chipping). As a result, there was a problem that the service life was reached in a relatively short time. In addition, high-speed heavy cutting of difficult-to-cut materials (drilling cutting, surface, etc.) is also possible for coated high-speed tools in which a hard base layer made of the (Ti, Al, V) N layer is provided on a tool base made of high-speed tool steel When used for cutting, grooving, shoulder processing, etc.), the service life is relatively short in the same reason that the lubricity of the hard coating layer is insufficient and chips easily adhere to the cutting edge. There was a problem of reaching.

Therefore, the present inventors, from the above-mentioned viewpoint, have excellent lubricity with a hard coating layer particularly in high-speed heavy cutting (drilling, chamfering, grooving, shouldering, etc.) of the difficult-to-cut materials. As a result of conducting research by focusing on the (Ti, Al, V) N layer that constitutes the hard coating layer of the conventional coated cutting tool,
(A) In the (Ti, Al, V) N layer constituting the hard coating layer, the lubricity is improved if the content ratio of the V component is increased, but 1 in the conventional (Ti, Al, V) N layer described above. When the V content is about ˜9 atomic%, the high lubricity required for high-speed heavy cutting of difficult-to-cut materials with high viscosity cannot be ensured. To satisfy these requirements satisfactorily, It is necessary to contain 50 to 70 atomic% of V, far exceeding -9 atomic%, while (Ti, Al, V) N layer containing 50 to 70 atomic% of V component is practically used as a hard coating layer. In order to provide it, it is necessary to contain a predetermined amount of Ti to ensure a predetermined high-temperature strength. In this case, however, it is inevitable that the content ratio of the Al component is extremely low. It must be extremely low in heat resistance.

(B) the composition _{formula: (Ti 1- (A + B} ) Al A V B) N ( provided that an atomic ratio, A is 0.01 to 0.10, B represents a 0.50 to 0.70) satisfies A (Ti, Al, V) N layer having a V content ratio of 50 to 70 atomic%;
Composition formula: (Ti _{1− (C + D)} Al _C V _D ) N (wherein, C is 0.25 to 0.40 and D is 0.20 to 0.35 in an atomic ratio), relative (Ti, Al, V) N layer with an increased Al component content,
Are alternately laminated in a state where each layer has an average layer thickness of 5 to 20 nm (nanometer), and the resulting (Ti, Al, V) N layer has the above-described structure due to the alternately laminated structure of thin layers. The excellent lubricity of the (Ti, Al, V) N layer (hereinafter referred to as the thin layer A) having a high V content, the V content ratio being relatively lower than that of the thin layer A, and the relative And (Ti, Al, V) N layer (hereinafter referred to as thin layer B) having a high Al content ratio has predetermined relatively high high temperature hardness and heat resistance.

(C) The (Ti, Al, V) N layer having the alternately laminated structure of the thin layer A and the thin layer B in (b) has excellent lubricity required for high-speed heavy cutting of difficult-to-cut materials. Although it does not have sufficiently satisfactory high-temperature hardness and heat resistance, it is provided as the upper layer of the hard coating layer, while the lower layer is insufficient in lubricity, but relatively Al component (Ti, Al, V) N layer having a composition corresponding to the above-described conventional hard coating layer having a high content ratio and excellent high-temperature hardness and heat resistance,
Compositional formula: (Ti _{1− (E + F)} Al _E V _F ) N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in terms of atomic ratio) (Ti, Al, V) N layer of single phase structure,
The resulting hard coating layer has high-temperature hardness, heat resistance, and high-temperature strength, in addition to excellent lubricity. The coated cutting tool has a high wear resistance for a long period of time without chipping even at high speed heavy cutting with high heat generation of the above difficult-to-cut materials. To come to show.
The research results shown in (a) to (c) above were obtained.

This invention was made based on the above research results, and on the surface of a high-speed tool steel substrate,
(A) Both are composed of an upper layer and a lower layer made of (Ti, Al, V) N, the upper layer has a thickness of 0.5 to 1.5 μm, and the lower layer has a thickness of 2 to 6 μm. ,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a single layer average thickness of 5 to 20 nm (nanometer),
The thin layer A is
Composition formula: (Ti _{1− (A + B)} Al _A V _B ) N (wherein A is 0.01 to 0.10 and B is 0.50 to 0.70 in terms of atomic ratio) (Ti , Al, V) N layer,
The thin layer B is
Composition formula: (Ti _{1− (C + D)} Al _C V _D ) N (wherein C is 0.25 to 0.40 and D is 0.20 to 0.35 in terms of atomic ratio) (Ti , Al, V) N layer,
(C) the lower layer has a single phase structure;
Composition formula: (Ti _{1− (E + F)} Al _E V _F ) N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.09 in atomic ratio) (Ti , Al, V) N layer,
A coating that exhibits excellent chipping resistance due to high-speed heavy cutting of difficult-to-cut materials (drilling, chamfering, grooving, shouldering, etc.) formed by vapor-depositing a hard coating layer consisting of It is characterized by a high speed tool (surface coated high speed tool steel cutting tool).

Next, the reason why the numerical values of the hard coating layer of the coated high-speed tool of the present invention are limited as described above will be described.
(A) Composition formula and layer thickness of the lower layer As described above, the Al component in the (Ti, Al, V) N layer constituting the hard coating layer improves high-temperature hardness and heat resistance, while the Ti component Has the effect of improving the high temperature strength and the lubricity of the V component, and the lower layer has a relatively high Al component content to provide high high temperature hardness and heat resistance. If the E value indicating the ratio is less than 0.50 in terms of the total amount of Ti and V (atomic ratio, the same shall apply hereinafter), the ratio of Ti will be relatively high, and high-speed heavy cutting of difficult-to-cut materials The required high temperature hardness and heat resistance cannot be ensured, and the progress of wear is accelerated rapidly. On the other hand, if the E value indicating the proportion of Al exceeds 0.65, The Ti ratio becomes too small, and the high-temperature strength decreases sharply. Since chipping (slight chipping) or the like is likely to occur, the E value was set to 0.50 to 0.65.
Further, the F value indicating the proportion of V is the proportion of the total amount of Ti and Al, and if it is less than 0.01, the predetermined lubricity cannot be ensured, while the F value exceeds 0.09. Since the high temperature hardness and the heat resistance are drastically reduced, the F value is determined to be 0.01 to 0.09.
Furthermore, if the layer thickness is less than 2 μm, the excellent high-temperature hardness and heat resistance cannot be imparted to the hard coating layer over a long period of time, resulting in a short tool life, while if the layer thickness exceeds 6 μm Since the chipping is likely to occur, the layer thickness is set to 2 to 6 μm.

(B) Composition formula of upper layer thin layer A The V component in (Ti, Al, V) N of the upper layer thin layer A is remarkably increased in content as described above to improve lubricity. Therefore, it is contained for the purpose of adapting to high-speed heavy cutting of difficult-to-cut materials with high heat generation. Therefore, if the B value is less than 0.50, the desired excellent lubricity cannot be ensured. If the B value exceeds 0.70, the high temperature strength that the layer itself should have cannot be secured, and chipping is likely to occur. Therefore, the B value was set to 0.50 to 0.70.
Further, the A value indicating the proportion of Al is the proportion of the total amount of Ti and V. If it is less than 0.01, the minimum high-temperature hardness and heat resistance cannot be ensured, which causes accelerated wear. On the other hand, when the A value exceeds 0.10, a tendency to decrease in high-temperature strength appears, which causes chipping. Therefore, the A value was determined to be 0.01 to 0.10.

(C) Composition formula of thin layer B of the upper layer In the thin layer B of the upper layer, the content ratio of the V component is relatively lower than that of the thin layer A, and the content ratio of the Al component is relatively By keeping the thin layer A high, the thin layer A has insufficient high-temperature hardness and heat resistance, reinforces the high-temperature hardness and heat resistance shortage of the adjacent thin layer A, and thus has the excellent thin layer A. The upper layer having a relatively high high-temperature hardness and heat resistance of the thin layer B is formed, but the C value indicating the Al content in the composition formula is less than 0.25. , The predetermined high temperature hardness and heat resistance cannot be ensured, which causes wear promotion. On the other hand, when the C value exceeds 0.40, the high temperature strength rapidly decreases, Since chipping is likely to occur in the layer itself, the C value is 0.25. It was set to ˜0.40.
Further, the D value indicating the ratio of V is the ratio of the total amount of Ti and Al. If the value is less than 0.20, the lubricity of the entire upper layer is inevitably deteriorated, while the D value exceeds 0.35. Then, since the high temperature strength of the entire upper layer is drastically reduced, the D value was set to 0.20 to 0.35.

(D) Layer thicknesses of upper layer thin layer A and layer B If each layer thickness is less than 5 nm, it is difficult to form each thin layer clearly with the above composition. Excellent lubricity, further high temperature hardness and heat resistance cannot be ensured, and if the thickness of each layer exceeds 20 nm, each thin layer has defects, ie, if it is thin layer A, high temperature hardness and heat resistance Insufficient lubricity, if thin layer B, insufficient lubricity will appear locally in the layer, which may cause chipping and promote the progress of wear. It was set to ˜20 nm.

(E) Layer thickness of the upper layer If the layer thickness is less than 0.5 μm, it cannot provide its own excellent lubricity and predetermined high temperature hardness and heat resistance to the hard coating layer over a long period of time, resulting in a short tool life. On the other hand, if the layer thickness exceeds 1.5 μm, chipping tends to occur. Therefore, the layer thickness is set to 0.5 to 1.5 μm.

  In the coated high-speed tool of the present invention, the hard coating layer is composed of a (Ti, Al, V) N layer. The upper layer of the hard coating layer has a predetermined laminated structure of the thin layer A and the thin layer B. It has excellent lubricity while maintaining high temperature hardness and heat resistance, and the lower layer of the single phase structure has excellent high temperature hardness and heat resistance. Easy and high-speed heavy cutting of difficult-to-cut materials with high heat generation that easily causes chipping (drilling cutting, chamfering, grooving, shoulder processing, etc.) It exhibits excellent wear resistance over a long period of time.

  Next, the coated high speed tool of the present invention will be described in detail with reference to examples.

From high-speed tool steel (JIS · SKH55) material with three dimensions of 8mm, 13mm, and 26mm in diameter, the diameter x length of the cutting edge is 6mm x 13mm, 10mm x 22mm, and High-speed tool steel end mill (hereinafter referred to as “high speed end mill”) bases 1 to 9 each having a size of 20 mm × 45 mm and having a four-blade square shape with a twist angle of 45 degrees were manufactured.

(A) Next, each of the high-speed end mill substrates 1 to 9 is ultrasonically cleaned in acetone and dried, and then in the radial direction from the central axis on the rotary table in the arc ion plating apparatus shown in FIG. For forming a thin layer A of an upper layer having a component composition corresponding to a target composition shown in Table 1 as a cathode electrode (evaporation source) on one side at a position separated by a predetermined distance Ti-Al-V alloy, Ti-Al-V alloy for forming upper layer thin layer B having the component composition corresponding to the target composition shown in Table 1, respectively, as the cathode electrode (evaporation source) on the other side Table 1 also shows cathode electrodes (evaporation sources) along the rotary table at positions 90 degrees apart from the Ti-Al-V alloys. The Ti-Al-V alloy for the lower layer formed having a component composition corresponding to the target composition is mounted,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, the interior of the apparatus is heated to 300 to 400 ° C. with a heater, and then rotated on the rotary table while rotating on the carbide substrate. A DC bias voltage of −1000 V is applied, and a current of 100 A is passed between the lower layer forming Ti—Al—V alloy and the anode electrode to generate an arc discharge. Bombarded with Al-V alloy,
(C) Nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 3 Pa, a DC bias voltage of −100 V is applied to the high-speed end mill base that rotates while rotating on the rotary table, and the lower part An arc discharge is generated by passing a current of 100 A between the Ti-Al-V alloy for layer formation and the anode electrode, so that the target composition and target layer thickness shown in Table 1 are simply applied to the surface of the high-speed end mill substrate. (Ti, Al, V) N layer having a one-phase structure is deposited as a lower layer of the hard coating layer,
(D) Next, the flow rate of nitrogen gas as a reaction gas introduced into the apparatus is adjusted to make a reaction atmosphere of 2 Pa, and a DC bias voltage of −100 V is applied to the high-speed end mill base that rotates while rotating on the rotary table. In the applied state, a predetermined current in a range of 50 to 200 A is passed between the cathode electrode and the anode electrode of the Ti-Al-V alloy for forming the thin layer A to generate arc discharge, and the high speed end mill A thin layer A having a predetermined thickness is formed on the surface of the substrate, and after the thin layer A is formed, the arc discharge is stopped, and instead, between the cathode electrode and the anode electrode of the Ti-Al-V alloy for forming the thin layer B Similarly, a predetermined current in the range of 50 to 200 A is supplied to generate arc discharge to form a thin layer B having a predetermined thickness, and then the arc discharge is stopped (in this case, starting from the formation of the thin layer B). The The thin layer A is formed again by arc discharge between the cathode electrode and the anode electrode of the Ti-Al-V alloy for forming the thin layer A, and the cathode electrode of the Ti-Al-V alloy for forming the thin layer B; The thin layer B is alternately and repeatedly formed by arc discharge between the anode electrodes, so that a thin layer A having a target composition and a single target layer thickness shown in Table 1 along the layer thickness direction is formed on the surface of the high-speed end mill substrate. An upper layer composed of alternating layers of thin layers B is vapor-deposited with an overall target layer thickness also shown in Table 1, so that the present invention surface-coated high-speed tool steel end mill (hereinafter referred to as the present invention) 1-9 were produced (referred to as coated high-speed end mills).

For comparison purposes, the surfaces of the high-speed end mill bases 1 to 9 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. 1. By depositing a hard coating layer composed of a (Ti, Al, V) N layer having a single phase structure with the target composition and target layer thickness shown in Table 2 under the same conditions as in Table 1, the comparative surface coating height Speed tool steel end mills (hereinafter referred to as comparative coated high speed end mills) 1 to 9 were produced.

Next, of the present invention coated high speed end mills 1-9 and comparative coated high speed end mills 1-9,
(A-1) About this invention coated high speed end mills 1-3 and comparative coated high speed end mills 1-3,
Work material-Plane: 100 mm x 250 mm, thickness: 50 mm JIS / SCMnH1 plate,
Cutting speed: 40 m / min. ,
Groove depth (cut): 4.5 mm,
Table feed: 80 mm / min,
A dry high-speed grooving test of manganese steel under the conditions (normal cutting speed, cutting and feeding are 20 m / min, 3.0 mm, and 60 mm / min, respectively)
(A-2) About this invention coated high speed end mills 4-6 and comparative coated high speed end mills 4-6,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 45 m / min. ,
Groove depth (cut): 7 mm,
Table feed: 180 mm / min,
A stainless steel dry-type high-speed grooving test (normal cutting speed, infeed and feed are 20 m / min, 4 mm and 75 mm / min, respectively)
(A-3) About this invention coated high speed end mills 7-9 and comparative coated high speed end mills 7-9,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm JIS / S15C plate material,
Cutting speed: 50 m / min. ,
Groove depth (cut): 16 mm,
Table feed: 130 mm / min,
Perform a dry high-speed grooving test of mild steel under the conditions (normal cutting speed, cutting and feeding are 20 m / min, 10 mm, and 65 mm / min, respectively)
In any of the above groove cutting tests (a-1) to (a-3), the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life. It was measured.
The measurement results of the above (a-1) to (a-3) are shown in Tables 1 and 2, respectively.

Using the high-speed tool steel (JIS SKH55) material used in Example 1 above, three types of high-speed tool steel drill bases (hereinafter referred to as high-speed drill bases) having different dimensions were manufactured by grinding. . The diameter x length of the groove forming portion is 4 mm × 25 mm (high-speed drill bases 1 to 3), 8 mm × 45 mm (high-speed drill bases 4 to 6) and 16 mm × 90 mm (high-speed drill bases 7 to 9), respectively. It has a two-blade shape of 30 degrees.

  Next, the cutting blades of these high-speed drill bases 1 to 9 are subjected to honing, ultrasonically cleaned in acetone, and in the dried state, the arc ion plating apparatus shown in FIG. 1. Under the same conditions as 1, the lower layer composed of a (Ti, Al, V) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 3, and also in Table 3 along the layer thickness direction. The surface-coated high-speed drill (hereinafter referred to as the present invention) is formed by vapor-depositing an upper layer composed of alternating layers of the thin layer A and the thin layer B having a target composition and a single target layer thickness with the overall target layer thickness shown in Table 3 below. (Referred to as the present invention coated high-speed drill) 1 to 9 were produced.

For comparison purposes, the surfaces of the high-speed drill bases 1 to 9 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then loaded into the arc ion plating apparatus shown in FIG. By vapor-depositing a hard coating layer composed of a (Ti, Al, V) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 4 under the same conditions as in Example 1 above, Comparative surface-coated high-speed drills (hereinafter referred to as comparative-coated high-speed drills) 1 to 9 were produced.

Next, of the present invention coated high speed drills 1-9 and comparative coated high speed drills 1-9,

(B-1) About this invention coated high speed drills 1-3 and comparative coated high speed drills 1-3,

Work material-Plane: 100 mm × 250, thickness: 50 mm JIS / S15C plate,
Cutting speed: 45 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 8 mm,

Wet mild high-speed drilling cutting test under normal conditions (normal cutting speed, feed, hole depth are 18 m / min, 0.1 mm / rev, 6 mm, respectively)
(B-2) About this invention coated high speed drills 4-6 and comparative coated high speed drills 4-6,
Work material-Plane: 100 mm x 250 mm, thickness: 50 mm JIS / SCMnH1 plate,
Cutting speed: 35 m / min. ,
Feed: 0.45 mm / rev,
Hole depth: 16 mm,
We perform wet high-speed drilling test of manganese steel under the conditions of (normal cutting speed, feed, hole depth are 18 m / min, 0.18 mm / rev, 12 mm, respectively)
(B-3) About this invention coated high speed drills 7-9 and comparative coated high speed drills 7-9,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 35 m / min. ,
Feed: 0.4 mm / rev,
Hole depth: 44 mm,
Wet stainless steel under high-speed wet drilling test (normal cutting speed, feed, hole depth are 18 m / min, 0.32 mm / rev, 24 mm, respectively)
In any wet high-speed drilling test (using water-soluble cutting oil), the number of drilling processes until the flank wear width of the tip cutting edge surface reached 0.3 mm was measured.

The measurement results of (b-1) to (b-3) are shown in Tables 3 and 4, respectively.

From the (Ti, Al, V) N of the present coated high speed end mills 1 to 9 and the present coated high speed drills 1 to 9 as the present coated high speed tool (cutting tool made from the present surface coated high speed tool) obtained as a result. Thin layer A and thin layer B of the upper layer constituting the hard coating layer, and the composition of the lower layer, and (Ti, Al, V) N of comparative coated high-speed end mills 1-9 and comparative coated high-speed drills 1-9 When the composition of the hard coating layer consisting of was measured by an energy dispersive X-ray analysis method using a transmission electron microscope, each showed substantially the same composition as the target composition.

  Further, when the average layer thickness of the constituent layers of the hard coating layer was subjected to cross-sectional measurement using a transmission electron microscope, all showed the same average value (average value of five locations) as the target layer thickness.

  From the results shown in Tables 1 to 4, the present coated high speed end mills 1 to 9 and the present coated high speed drills 1 to 9 which are the present coated high speed tools (the present surface coated high speed tool steel cutting tools) A lower layer having a single-phase structure made of (Ti, Al, V) N and a laminated layer structure of thin layers A and B each having a thickness of 5 to 20 nm. In particular, since the lower layer has excellent high-temperature hardness and heat resistance, and the upper layer has excellent lubricity, and the hard coating layer has these excellent characteristics, particularly mild steel Even when used for high-speed heavy cutting with high heat generation of highly viscous difficult-to-cut materials such as stainless steel and high-manganese steel, it exhibits excellent lubricity, and the chips adhere to the cutting edge during cutting. Good without The comparative coated high-speed end mills 1 to 9 and the comparative coated high-speed drills 1 to 9 whose hard coating layer is composed of a (Ti, Al, V) N layer having a single-phase structure while exhibiting chipping properties are the above difficult-to-cut materials. In high-speed heavy cutting, it is clear that chipping occurs at the cutting edge due to lack of lubrication, and the service life is reached in a relatively short time.

  As described above, the coated high-speed tool according to the present invention is not only capable of cutting under normal cutting conditions such as various carbon steels, low alloy steels, and ordinary cast iron, but also generates high heat particularly in difficult-to-cut materials. Therefore, it exhibits excellent chipping resistance even in high-speed heavy cutting, exhibits excellent cutting performance over a long period of time, and has wide versatility with work materials. It is possible to respond satisfactorily to energy saving, energy saving, and cost reduction.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated high-speed tool is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of a normal arc ion plating apparatus.

Claims (1)

On the surface of the cutting tool base made of high-speed tool steel,
(A) All are composed of an upper layer and a lower layer made of a composite nitride of Ti, Al, and V (vanadium), the upper layer being an average layer of 0.5 to 1.5 μm, and the lower layer being an average layer of 2 to 6 μm Each has a thickness,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a single layer average thickness of 5 to 20 nm (nanometer),
The thin layer A is
Ti satisfying the composition formula: (Ti _{1− (A + B)} Al _A V _B ) N (wherein A is 0.01 to 0.10 and B is 0.50 to 0.70 in atomic ratio) A composite nitride layer of Al and V;
The thin layer B is
Ti satisfying the composition formula: (Ti _{1- (C + D)} Al _C V _D ) N (wherein C represents 0.25 to 0.40 and D represents 0.20 to 0.35 in atomic ratio) A composite nitride layer of Al and V,
(C) the lower layer has a single phase structure;
Ti satisfying the composition formula: (Ti _{1− (E + F)} Al _E V _F ) N (wherein E represents 0.50 to 0.65 and F represents 0.01 to 0.09 in atomic ratio) A composite nitride layer of Al and V;
A surface-coated high-speed tool steel cutting tool that exhibits excellent chipping resistance in high-speed heavy cutting of difficult-to-cut materials, formed by vapor-depositing a hard coating layer made of

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