JPH08100239A - Alloy tool steel - Google Patents

Abstract

PURPOSE: To improve hot workability and fatigue characteristic by incorporating specific amounts of REM into an alloy tool steel of specific composition and also controlling respective contents of S, O, N, Al, and P. CONSTITUTION: The alloy tool steel has a composition consisting of, by weight, one or >=2 kinds among 0.35-1.50% C, 0.1-2.0% Si, 0.1-1.5% Mn, 2.0-10.0% Cr, 1.5-30.0% (2Mo+W), and 0.5-5.0% V, 0.001-0.60% REM, further one or >=2 kinds among 1.0-20.0% Co, 0.01-2.0% Ni, 0.25-1.0% Cu, and 0.001-0.050% B, and the balance essentially Fe. Further, the contents of S, O, N, Al, and P are limited to <=0.0020%, <=0.0030%. <=0.020%, <=0.020%, and <=0.020%, respectively. If necessary, one or >=2 elements among Nb, Ta, Zr, Hf, Ti, Sc, and Y are further incorporated. By this method, the occurrence of sand mark can be prevented, and a tool excellent in toughness and long in service life can be obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is used as a material for tools such as high speed tool steel, cold die steel, hot die steel, and casting tools, and is an alloy excellent particularly in hot workability and fatigue characteristics. It relates to tool steel.

[0002]

2. Description of the Related Art Conventionally, JIS S is used as an alloy tool steel.
KS, SKD, SKT, SKH, etc., cutting tools,
It is used in a wide range of applications such as extrusion dies, drawing dies, roll dies, wire dies, gauges, press dies, and die casting dies.

[0003] In such an alloy tool steel, it is required that a tool having a desired shape can be easily manufactured, and that it has excellent hot workability and fatigue characteristics so that a long life can be obtained. You.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned demands, and provides an alloy tool steel having characteristics required for a tool material, and particularly excellent in hot workability and fatigue characteristics. It is an object.

[0005]

The present invention provides an alloy tool steel such as a high speed tool steel, a cold die steel, a hot die steel, a casting tool, etc., in which REM is contained in an amount of 0.001 to 0.60% by weight. : 0.0020% by weight or less, O: 0.0030
Wt% or less, N: 0.020 wt% or less, Al: 0.0
It is characterized in that it is regulated to 20% by weight or less and P: 0.020% by weight or less.

[0006] In the alloy tool steel of the present invention, the REM content (total amount of one or more rare earth elements) is set to 0.1.
The reason why the content of 001 to 0.60% by weight is that the addition of REM can improve the toughness of the tool steel and especially the impact resistance. 001 wt% or more was added. However, if added in a large amount, toughness and workability are deteriorated.
It was 60% by weight or less.

The reason why the S content is set to 0.0020% by weight or less and the O content is set to 0.0030% by weight or less is as follows.
This is because, by regulating the amounts of S and O, the generation of ground flaws is suppressed and the ground flaw grade is improved.

[0008] Similarly, in order to further improve the ground flaw grade, N: 0.020% by weight or less, Al: 0.020% by weight or less, and P: 0.020% by weight or less.

Further, the addition of REM at the time of manufacturing is 1
It is desirable to carry out at 530 to 1550 ° C., particularly at 1540 to 1545 ° C., whereby the occurrence of ground defects can be considerably suppressed.

[0010] In the first invention and the second invention of the present invention,
The alloy tool steel is a high speed tool steel, and in weight%, C:
0.35 to 1.50%, Si: 0.1 to 2.0%, M
n: 0.1-1.5%, Cr: 2.0-10.0%, and 2Mo + W: 1.5-30.0%, V: 0.5-.
One or more of 5.0%, REM: 0.0
01 to 0.60%, Co: 1.0 to 20.0%,
Ni: 0.01 to 2.0%, Cu: 0.25 to 1.0
%, B: one or more of 0.001 to 0.050%, S: 0.0020% or less, O: 0.0
030% or less, N: 0.020% or less, Al: 0.02
0% or less, P: 0.020% or less, and in some cases, Nb: 0.01 to 5.0%, Ta: 0.01
To 5.0%, Zr: 2.0% or less, Hf: 2.0% or less, Ti: 2.0% or less, Sc: 0.001 to 2.0
%, Y: 2.0% or less, one or more of them may be included, and the balance may be substantially Fe.

Here, C is an element effective for securing hardness and wear resistance required for high-speed tool steel,
In order to obtain such an effect, the content is preferably 0.35% or more. However, if the content is too large, the toughness and workability are reduced. Therefore, the content is preferably set to 1.50% or less.

Si is an element which acts as a deoxidizing agent and is effective for improving temper hardness, toughness and corrosion resistance. To obtain such an effect, it is necessary to contain 0.1% or more. Good. However, if added in a large amount, the hot workability is impaired and the toughness is deteriorated, so the content is preferably 2.0% or less.

Mn is an element that acts as a deoxidizing and desulfurizing agent and increases the cleanliness of steel and also contributes to the improvement of hardenability. Is good. However, if the content is too large, the hot workability is impaired. Therefore, the content is preferably 1.5% or less.

Cr is an element effective for increasing the strength of tool steel, particularly high-temperature strength, and for enhancing the thermal shock resistance. To obtain such an effect, it is preferable to add 2.0% or more. . However, if it is too large, the toughness and workability are deteriorated, so it is preferable to set it to 10.0% or less.

Since Mo, W and V are effective elements for forming carbides and increasing the heat treatment hardness and improving the wear resistance, one or more of them may be added. . In this case, Mo is an element having a greater effect than W. In order to obtain such an effect, Mo is equal to or more than 1.5% by 2Mo + W (including the case where either of them is 0) and V is set to 0.5%. % Or more is better. However, if the amount is too large, the toughness decreases and the amount of coarse carbides increases, which adversely affects the fatigue characteristics. Therefore, it is preferable that 2Mo + W is 30.0% or less and V is 5.0% or less.

Nb, Ta, Zr, Hf, Ti, Sc, Y
Is an element effective for forming carbides to increase heat treatment hardness and improve wear resistance. Therefore, these elements may be appropriately selected and added in the above range.

Since Co, Ni, Cu and B all strengthen the matrix and enhance the strength, impact resistance and heat check resistance of the tool steel, these elements are appropriately selected and added in the above range. Is also good. Further, B is an element effective for improving the hardenability of steel and fixing N in the steel in the form of BN to eliminate the adverse effects of N. Therefore, B may be appropriately added within the above range.

Since Mg, Ca, Pb, Bi, Te and Se are effective elements for improving the machinability of steel, one or more of them may be added in the above range.

Since N, Al, and P decrease the toughness of the tool steel, it is preferable that the upper limit is set as described above.

In the third and fourth inventions of the present invention, the alloy tool steel is a cold die steel, and C: 0.
35 to 2.50%, Si: 0.1 to 2.0%, Mn:
0.1 to 1.5%, Cr: 3.0 to 20.0%, and Mo: 0.10 to 5.0%, W: 0.10 to 5.0%,
V: one or more of 0.01 to 5.0%,
REM: 0.001 to 0.60%, further Co: 1.0
~ 20.0%, Ni: 0.01 ~ 2.0%, Cu: 0.
01 to 2.0%, B: contains one or more of 0.001 to 0.050%, S: 0.0020% or less, O: 0.0030% or less, N: 0.020 %Less than,
Al: 0.020% or less, P: 0.020% or less, and in some cases, Nb: 0.01 to 5.0%,
Ta: 0.01 to 5.0%, Zr: 0.001 to 2.0
%, Hf: 0.001 to 2.0%, Ti: 0.001 to
2.0%, Sc: 0.01 to 2.0%, Y: 0.001
Of at least 2.0%, and the balance substantially consists of Fe.

Here, C is an element effective for ensuring the hardness and wear resistance required for cold die steel,
In order to obtain such an effect, the content is preferably 0.35% or more. However, if the content is too large, the toughness and the workability are reduced. Therefore, the content is preferably set to 2.50% or less.

Si is an element which acts as a deoxidizing agent and is also effective for improving the tempering hardness, the toughness and the corrosion resistance. In order to obtain such effects, it is necessary to contain 0.1% or more. Good. However, if added in a large amount, the hot workability is impaired and the toughness is deteriorated, so the content is preferably 2.0% or less.

Mn is an element that acts as a deoxidizing agent and a desulfurizing agent, and contributes not only to the cleanliness of steel but also to the improvement of hardenability. To obtain such an effect, 0.1% or more is added. Is good. However, if the content is too large, the hot workability is impaired. Therefore, the content is preferably 1.5% or less.

Cr is an element effective for increasing the strength of the tool steel, particularly high-temperature strength, and for enhancing the thermal shock resistance. To obtain such an effect, it is preferable to add 3.0% or more. . However, if the content is too large, the toughness and the workability are deteriorated. Therefore, the content is preferably set to 20.0% or less.

Mo, W, and V are elements effective in forming carbides and increasing heat treatment hardness to improve wear resistance. Therefore, one or more of these elements may be added. . Then, in order to obtain such an effect, Mo is set to 0.
It is preferable to add 10% or more, W to 0.10% or more, and V to 0.01% or more. However, if the amount is too large, the toughness decreases and the amount of coarse carbides increases, which adversely affects the fatigue properties. Therefore, Mo is 5.0% or less, W is 5.0% or less, and V is 5.0% or less. Is good.

Nb, Ta, Zr, Hf, Ti, Sc, Y
Is an element effective for forming carbides to increase heat treatment hardness and improve wear resistance. Therefore, these elements may be appropriately selected and added in the above range.

Since Co, Ni, Cu and B all strengthen the matrix and enhance the strength, impact resistance and heat check resistance of the tool steel, these elements are appropriately selected and added in the above range. Is also good. Further, B is an element effective for improving the hardenability of steel and fixing N in the steel in the form of BN to eliminate the adverse effects of N. Therefore, B may be appropriately added within the above range.

Since Mg, Ca, Pb, Bi, Te and Se are effective elements for improving the machinability of steel, one or more of them may be added in the above range.

Since N, Al and P reduce the toughness of the tool steel, it is preferable to limit them to the above-mentioned upper limit.

In the fifth and sixth aspects of the present invention, the alloy tool steel is a hot die steel and has a C: 0.20% by weight.
0.50%, Si: 0.1-2.0%, Mn: 0.1
~ 1.5%, Cr: 2.0-8.0%, and Mo:
0.10 to 5.0%, W: 0.10 to 5.0%, V:
One or more of 0.01 to 5.0%, RE
M: 0.001 to 0.60%, further Co: 0.01 to
10.0%, Ni: 0.01 to 2.0%, Cu: 0.0
1 to 2.0%, B: one or more of 0.001 to 0.050%, S: 0.0020% or less,
O: 0.0030% or less, N: 0.020% or less, A
l: 0.020% or less, P: 0.020% or less, and in some cases, Nb: 0.01 to 5.0%,
Ta: 0.01 to 5.0%, Zr: 0.001 to 2.0
%, Hf: 0.001 to 2.0%, Ti: 0.001 to
2.0%, Sc: 0.001 to 2.0%, Y: 0.00
One or two or more of 1 to 2.0% may be contained, and the balance may be substantially composed of Fe.

Here, C is an element effective for ensuring the hardness and wear resistance required for hot die steel,
In order to obtain such an effect, the content is preferably 0.20% or more. However, if the content is too large, the toughness and the workability are reduced. Therefore, the content is preferably set to 0.50% or less.

Si is an element which acts as a deoxidizing agent and is effective in improving the tempering hardness and the toughness and the corrosion resistance. To obtain such an effect, Si is contained in an amount of 0.1% or more. Good. However, if added in a large amount, the hot workability is impaired and the toughness is deteriorated, so the content is preferably 2.0% or less.

Mn is an element that acts as a deoxidizing and desulfurizing agent and enhances the cleanliness of steel and also contributes to the improvement of hardenability. Is good. However, if the content is too large, the hot workability is impaired. Therefore, the content is preferably 1.5% or less.

Cr is an element effective for increasing the strength of the tool steel, particularly high-temperature strength, and for enhancing the thermal shock resistance. To obtain such an effect, it is preferable to add 2.0% or more. . However, if the content is too large, the toughness and the workability are deteriorated.

Since Mo, W, and V are elements that form carbides and are effective in increasing heat treatment hardness and improving wear resistance, one or more of these may be added. . Then, in order to obtain such an effect, Mo is set to 0.
It is preferable to add 10% or more, W to 0.10% or more, and V to 0.01% or more. However, if the amount is too large, the toughness decreases and the amount of coarse carbides increases, which adversely affects the fatigue properties. Therefore, Mo is 5.0% or less, W is 5.0% or less, and V is 5.0% or less. Is good.

Nb, Ta, Zr, Hf, Ti, Sc, Y
Is an element effective for forming carbides to increase heat treatment hardness and improve wear resistance. Therefore, these elements may be appropriately selected and added in the above range.

Since Co, Ni, Cu and B all strengthen the matrix and enhance the strength, impact resistance and heat check resistance of the tool steel, these elements are appropriately selected and added in the above range. Is also good. Further, B is an element effective for enhancing the hardenability of the steel and fixing N in the steel in the form of BN to eliminate the adverse effect of N, so it may be appropriately added within the above range.

Since Mg, Ca, Pb, Bi, Te, and Se are effective elements for improving the machinability of steel, one or more of them may be added in the above range.

Since N, Al, and P decrease the toughness of the tool steel, it is preferable to control the upper limit as described above.

In the seventh and eighth inventions of the present invention, the alloy tool steel is a casting tool, and in terms of% by weight, C: 1.0 to
4.0%, Si: 0.1 to 3.0%, Mn: 0.05 to
10.0%, Cr: 25.0-35.0%, Co: 3
5.0-65.0%, and Mo: 0.05-15.0.
%, W: 10.0 to 25.0%, V: 0.1 to 15.0
% Or more, REM: 0.001 to
0.60%, further Ni: 0.01 to 15.0%, C
u: 0.01% to 2.0%, B: 0.005% to 0.8%, S: 0.0020%
Hereinafter, O: 0.0030% or less, N: 0.020% or less, Al: 0.020% or less, P: 0.020% or less, and in some cases, Nb: 0.1 to 15.0.
%, Ta: 0.1-10.0%, Zr: 0.01-0.
5%, Hf: 2.0% or less, Ti: 0.01 to 0.5
%, Sc: 0.001 to 2.0%, Y: 2.0% or less, and one or more of them may be included, and the balance may be substantially Fe.

Here, C is an element effective for maintaining the matrix structure in austenite, forming carbides at the time of casting and solidifying to increase the hardness, and improving the wear resistance. For this reason, the content is preferably 1.0% or more. However, if the amount is too large, the amount of carbides becomes excessively large, and coarse carbides are easily formed to reduce toughness. Therefore, it is preferable to set it to 4.0% or less.

Si is an element that acts as a deoxidizing agent and is effective in improving castability, and is preferably contained in an amount of 0.1% or more in order to sufficiently obtain such an effect.
However, if the content is too large, hot workability and toughness are impaired. Therefore, the content is preferably set to 3.0% or less.

Mn acts as a deoxidizing agent and a desulfurizing agent and is an element effective for enhancing the cleanliness of steel. For this purpose, it is preferable to contain 0.05% or more. The matrix structure can be made austenite by adding a certain amount, but the effect is not improved even if it is contained in a large amount, so it is preferable to set the content to 10.0% or less.

Cr is an element effective for improving wear resistance by hardening by solid solution or by forming carbides, and also for improving oxidation resistance at high temperatures. Should preferably be contained at 25% or more. However, if the amount is too large, the amount of carbides becomes too large due to the balance with the amount of C, and coarse carbides are easily formed, and the toughness is reduced.

Co is an element effective in stabilizing austenite, improving the corrosion resistance, and improving the strength and toughness of the matrix at high temperatures. To obtain such an effect, Co is contained in an amount of 35.0% or more. It is better to let them do it. However, even if added in a large amount, the effect is not so much improved, and since it is an expensive element, it is preferable to set it to 65.0% or less.

Since Ni and Cu are elements effective for maintaining the matrix structure in austenite and improving corrosion resistance and seizure resistance, they may be added in the above range.

W, Mo, and V are effective elements for forming carbides of high hardness to improve wear resistance. To obtain such an effect, W is 10.0% or more and Mo is 0%. .0
It is preferable to contain 5% or more and V of 0.1% or more. However, if it is too large, the thermal shock resistance deteriorates and it may cause cracking. Therefore, it is preferable that W is 25.0% or less, Mo is 15.0% or less, and V is 15.0% or less.

Nb, Ta, Zr, Hf, Ti, Sc, Y
Are all carbide-forming elements, and are effective elements for forming high-hardness carbides and improving wear resistance, so that they may be appropriately selected from these and added within the above range. .

B enhances the hardenability of the steel and increases the N content in the steel.
Is an element effective for fixing BN in the form of BN to eliminate the adverse effect of N, so that it may be appropriately added within the above range.

Since Mg, Ca, Pb, Bi, Te and Se are effective elements for improving the machinability of the tool material, one or more of them may be added in the above range. .

N, Al, and P reduce the toughness of the tool steel, so it is preferable to control the N, Al, and P to the above upper limits.

[0052]

EXAMPLE A tool material of various components was melted by a vacuum induction melting furnace, and RE was melted at a melting temperature of 1530 to 1550 ° C.
M was added and stirred, and the materials of the chemical components shown in Tables 1 and 2 were melted and then ingots were obtained to obtain ingots.

[0053]

[Table 1]

[0054]

[Table 2]

Next, the ingot was heated at 700 to 750 ° C.
After heating for 3 hours, forging, then heating at 800 ° C. for 3 hours and cooling at 20 ° C./hr for solution treatment were performed, and then the ground defect grade, hot workability and fatigue properties were examined. Note that the ground flaw grade was examined by a visual test performed according to JIS G 0556, hot workability was examined by a grease test, and fatigue properties were examined by a test according to JIS Z 2273. The results are shown in Tables 3 and 4.

[0056]

[Table 3]

[0057]

[Table 4]

As shown in Tables 1 to 4, various alloy tool steels contain REM (one or more rare earth elements including Y) in a range of 0.001 to 0.60% by weight. S is 0.0020% by weight or less, and O is 0.0% by weight.
The steels of the present invention in which 030% by weight or less, N is 0.020% by weight or less, Al is 0.020% by weight or less, and P is regulated to 0.020% by weight or less, all have less flaws than the comparative steels. It is clear that the hot workability and the fatigue properties are also excellent, confirming that the tool steel is high quality and high durability.

[0059]

As described above, the present invention relates to an alloy tool steel such as a high speed tool steel, a cold die steel, a hot die steel, a casting tool, and the like.
60% by weight and S: 0.0020% by weight
Hereinafter, O: 0.0030% by weight or less, N: 0.020% by weight or less, Al: 0.020% by weight or less, P: 0.02%
Since the content is regulated to 0% by weight or less, occurrence of ground flaws is suppressed,
It has excellent effects such as excellent hot workability and toughness, particularly excellent impact resistance, a large fatigue strength and a long life tool.

Claims (8)

[Claims] C .: 0.35 to 1.50% by weight,
Si: 0.1-2.0%, Mn: 0.1-1.5%, C
r: 2.0 to 10.0%, and 2Mo + W: 1.5 to
30.0%, V: one or more of 0.5 to 5.0%, REM: 0.001 to 0.60%, and further C
o: 1.0 to 20.0%, Ni: 0.01 to 2.0%,
Cu: 0.25 to 1.0%, B: 0.001 to 0.05
0%, one or more of them, S: 0.00
20% or less, O: 0.0030% or less, N: 0.020
% Or less, Al: 0.020% or less, P: 0.020% or less, the balance being substantially Fe. 2. C: 0.35 to 1.50% by weight,
Si: 0.1-2.0%, Mn: 0.1-1.5%, C
r: 2.0 to 10.0%, and 2Mo + W: 1.5 to
30.0%, V: one or more of 0.5 to 5.0%, REM: 0.001 to 0.60%, and further C
o: 1.0 to 20.0%, Ni: 0.01 to 2.0%,
Cu: 0.25 to 1.0%, B: 0.001 to 0.05
0%, one or more of them, S: 0.00
20% or less, O: 0.0030% or less, N: 0.020
%, Al: 0.020% or less, P: 0.020% or less, Nb: 0.01 to 5.0%, Ta:
0.01-5.0%, Zr: 2.0% or less, Hf: 2.
0% or less, Ti: 2.0% or less, Sc: 0.001 to
2.0%, Y: An alloy tool steel containing one or more of 2.0% or less, and the balance substantially consisting of Fe. 3. C: 0.35 to 2.50% by weight,
Si: 0.1-2.0%, Mn: 0.1-1.5%, C
r: 3.0-20.0%, and Mo: 0.10-5.
0%, W: 0.10 to 5.0%, V: 0.01 to 5.0
% Or more, REM: 0.001 to
0.60%, Co: 1.0 to 20.0%, Ni:
0.01 to 2.0%, Cu: 0.01 to 2.0%, B:
Includes one or more of 0.001 to 0.050%, S: 0.0020% or less, O: 0.0030%
Hereinafter, N: 0.020% or less, Al: 0.020% or less, P: 0.020% or less, and the balance is substantially Fe
An alloy tool steel characterized by comprising: C .: 0.35 to 2.50% by weight,
Si: 0.1-2.0%, Mn: 0.1-1.5%, C
r: 3.0-20.0%, and Mo: 0.10-5.
0%, W: 0.10 to 5.0%, V: 0.01 to 5.0
% Or more, REM: 0.001 to
0.60%, Co: 1.0 to 20.0%, Ni:
0.01 to 2.0%, Cu: 0.01 to 2.0%, B:
Includes one or more of 0.001 to 0.050%, S: 0.0020% or less, O: 0.0030%
Hereinafter, N is regulated to 0.020% or less, Al is regulated to 0.020% or less, and P is regulated to 0.020% or less.
01-5.0%, Ta: 0.01-5.0%, Zr:
0.001 to 2.0%, Hf: 0.001 to 2.0%,
Ti: 0.001 to 2.0%, Sc: 0.01 to 2.0
%, Y: 0.001 to 2.0% of one or two or more, and the balance being substantially Fe. 5. C: 0.20 to 0.50% by weight,
Si: 0.1-2.0%, Mn: 0.1-1.5%, C
r: 2.0-8.0%, and Mo: 0.10-5.0.
%, W: 0.10 to 5.0%, V: 0.01 to 5.0%
One or more of them, REM: 0.001 to
0.60%, Co: 0.01 to 10.0%, N
i: 0.01 to 2.0%, Cu: 0.01 to 2.0%,
B: contains one or more of 0.001 to 0.050%, S: 0.0020% or less, O: 0.003
0% or less, N: 0.020% or less, Al: 0.020%
Hereinafter, P is regulated to 0.020% or less, and the balance is substantially F
e, an alloy tool steel. 6. C: 0.20 to 0.50% by weight,
Si: 0.1-2.0%, Mn: 0.1-1.5%, C
r: 2.0-8.0%, and Mo: 0.10-5.0.
%, W: 0.10 to 5.0%, V: 0.01 to 5.0%
One or more of them, REM: 0.001 to
0.60%, Co: 0.01 to 10.0%, N
i: 0.01 to 2.0%, Cu: 0.01 to 2.0%,
B: contains one or more of 0.001 to 0.050%, S: 0.0020% or less, O: 0.003
0% or less, N: 0.020% or less, Al: 0.020%
Hereinafter, P: 0.020% or less is regulated, and Nb:
0.01 to 5.0%, Ta: 0.01 to 5.0%, Z
r: 0.001 to 2.0%, Hf: 0.001 to 2.0
%, Ti: 0.001 to 2.0%, Sc: 0.001 to
2.0%, Y: An alloy tool steel containing one or more of 0.001 to 2.0%, and the balance substantially consisting of Fe. 7. C: 1.0 to 4.0% by weight, S
i: 0.1 to 3.0%, Mn: 0.05 to 10.0%,
Cr: 25.0-35.0%, Co: 35.0-65.
0%, Mo: 0.05-15.0%, W: 10.
0 to 25.0%, V: one or more of 0.1 to 15.0%, REM: 0.001 to 0.60%, Ni: 0.01 to 15.0%, Cu: 0.01-
2.0%, B: one or more of 0.005 to 0.8%, S: 0.0020% or less, O: 0.
0030% or less, N: 0.020% or less, Al: 0.0
Alloy tool steel characterized by being restricted to not more than 20% and P: not more than 0.020%, and the balance substantially consisting of Fe. 8. C: 1.0 to 4.0% by weight, S
i: 0.1 to 3.0%, Mn: 0.05 to 10.0%,
Cr: 25.0-35.0%, Co: 35.0-65.
0%, Mo: 0.05-15.0%, W: 10.
0 to 25.0%, V: one or more of 0.1 to 15.0%, REM: 0.001 to 0.60%, Ni: 0.01 to 15.0%, Cu: 0.01-
2.0%, B: one or more of 0.005 to 0.8%, S: 0.0020% or less, O: 0.
0030% or less, N: 0.020% or less, Al: 0.0
20% or less, P: 0.020% or less, and N
b: 0.1 to 15.0%, Ta: 0.1 to 10.0%,
Zr: 0.01 to 0.5%, Hf: 2.0% or less, T
i: 0.01 to 0.5%, Sc: 0.001 to 2.0
%, Y: an alloy tool steel containing one or more of 2.0% or less, and the balance substantially consisting of Fe.