US2024011135A1PendingUtilityA1
Hot work tool steel
Est. expiryJun 12, 2040(~13.9 yrs left)· nominal 20-yr term from priority
C21D 8/00C21D 6/002C22C 38/24C22C 38/22C22C 38/04C22C 38/06C22C 38/02C21D 1/18C21D 1/773C21D 1/32C21D 8/005C21D 9/0068C21D 2211/001C22C 38/58C22C 38/38C22B 9/18C21D 1/25C22B 9/20C22C 38/52C22C 38/44C22C 38/46C22C 38/42C22C 38/001C21D 9/20C22C 38/12
51
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Claims
Abstract
A matrix type hot work tool steel, in use, has an improved abrasive wear resistance in demanding applications. The steel is suited for applications in hot forging, die casting or hot extrusion. It is also suitable for press hardening, in particular for press hardening of Advance High Strength Steel (AHSS) and has a high hot wear resistance. The hot work tool steel has a composition including, in weight % (wt. %): C 0.65-0.85; Si 0.03-0.8; Mn 0.1-1.8; Cr 4.5-6.6; Mo 1.8-3.5; V 1.3-2.3; Al≤0.1; N≤0.12; Ni≤1; W≤0.5; Co≤2; Cu≤1; Nb≤0.1; Ti≤0.05; Zr≤0.05; Ta≤0.05; B≤0.01; Ca≤0.01; Mg≤0.01; REM≤0.2; and balance Fe and impurities.
Claims
exact text as granted — not AI-modified1 . A hot work tool steel for hot forging, press hardening, die casting or hot extrusion consisting in weight % (wt. %):
C
0.65-0.85
Si
0.03-0.8
Mn
0.1-1.8
Cr
4.5-6.6
Mo
1.8-3.5
V
1.3-2.3
Al
≤0.1
N
≤0.12
Ni
≤1
W
≤0.5
Co
≤2
Cu
≤1
Nb
≤0.1
Ti
≤0.05
Zr
≤0.05
Ta
≤0.05
B
≤0.01
Ca
≤0.01
Mg
≤0.01
REM
≤0.2, and
balance Fe and impurities.
2 . The hot work tool steel according to claim 1 , wherein the steel fulfils at least one of the following requirements:
C
0.65-0.8
Si
0.05-0.6
Mn
0.2-0.8
Cr
4.5-5.6
Mo
2.0-2.5
V
1.5-1.9
Al
≤0.05
N
≤0.08
Ni
≤0.5
W
≤0.5
Co
≤2
Cu
≤0.5
Nb
≤0.05
Ti
≤0.01
Zr
≤0.01
Ta
≤0.01
B
≤0.006
Ca
≤0.005
Mg
≤0.005, and
REM
≤0.1.
3 . The hot work tool steel according to claim 1 , wherein the steel fulfils at least one of the following requirements:
C
0.65-0.75
Si
0.15-0.5
Mn
0.4-0.5
Cr
4.9-5.1
Mo
2.2-2.3
V
1.5-1.7
Al
≤0.03
N
≤0.05
Ni
0.25
W
≤0.2
Co
≤1
Cu
≤0.2
Nb
≤0.005
Ti
≤0.005
Zr
≤0.005
Ta
≤0.005, and
REM
≤0.05.
4 . The hot work tool steel according to claim 1 , wherein the steel comprises carbides having a size of ≥1 μm and fulfils at least one of the following requirements concerning the amounts of carbides in volume %:
VC
0.2-4
M 6 C
≤2, and
M 7 C 3
≤2.
5 . The hot work tool steel according to claim 4 , wherein the steel comprises carbides having a size of ≥1 μm and fulfils at least one of the following requirements concerning the amounts of carbides in volume %:
VC
0.5-3
M 6 C
≤0.5, and
M 7 C 3
≤0.5.
6 . The hot work tool steel according to claim 5 , wherein the steel comprises carbides having a size of ≥1 μm and fulfils at least one of the following requirements concerning the amounts of said carbides in volume %:
VC
1.5-2.3
M 6 C
≤0.1, and
M 7 C 3
≤0.1.
7 . The hot work tool steel according to claim 1 , wherein the steel after hardening and tempering has a hardness of 55-57 HRC and wherein the steel fulfils at least one of the following requirements:
Rp0.2
≥1750 MPa
Rm
≥2100 MPa
A5
≥6%
Z
≥20%, and
a cleanliness fulfilling the following maximum requirements with respect to micro-slag according to ASTM E45-97, Method A, Plate I-r:
A
A
B
B
C
C
D
D
T
H
T
H
T
H
T
H
1.0
0
1.5
1.0
0
0
1.5
1.0.
8 . The hot work tool steel according to claim 1 , wherein the steel fulfils at least one of the following requirements:
C
0.66-0.75
Si
0.15-0.25
Mo
2.2-2.3
V
1.52-1.68
Al
0.001-0.03
N
≤0.05
W
≤0.1
Co
≤1
Cu
≤0.15
Nb
≤0.005
Ti
≤0.005, and
Zr
≤0.005.
9 . The hot work tool steel according to claim 1 , wherein the steel fulfils at least one of the following requirements:
C
0.66-0.75
Si
0.15-0.25
Mo
2.2-2.3
V
1.52-1.68
Al
0.005-0.03
N
≤0.05
W
≤0.1
Co
≤0.5
Cu
≤0.15
Nb
≤0.005
Ti
≤0.005, and
Zr
≤0.005.
10 . The hot work tool steel according to claim 1 , having a mean hardness of ≤360 HBW, wherein the steel has a thickness of at least 100 mm and the maximum deviation from the mean Brinell hardness value in the thickness direction measured in accordance with ASTM E10-01 is less than 10%, and wherein the minimum distance of the center of the indentation from the edge of the specimen or edge of another indentation shall be at least two and a half times the diameter of the indentation and the maximum distance shall be no more than 4 times the diameter of the indentation.
11 . Use of the hot work tool steel according to claim 1 as a tool for hot forging, press hardening, die casting, high pressure die casting or hot extrusion.
12 . The hot work tool steel according to claim 10 , wherein the maximum deviation from the mean Brinell hardness value in the thickness direction measured in accordance with ASTM E10-01 is less than 5%.Cited by (0)
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