DETAILED ACTION
Status of Claims
Claims 8-24 remain pending in the application. Claims 12-23 have been withdrawn due to a restriction requirement. Claims 1-7 have been cancelled. Claims 8-11 and 24 are presented for examination on the merits. No claim amendments were filed with Applicant’s remarks submitted 04/15/2026.
Claim Rejections - 35 USC § 103
Claims 8-11 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2018/062380 A1 of Hasegawa (cited in prior Office action and using its equivalent US 2019/0194775 A1 as its English machine translation).
Regarding claims 8-9, Hasegawa teaches a steel sheet (Abstract, reads on claimed steel sheet).
List 1
Instant claims (mass%)
Hasegawa (mass%)
Hasegawa – Example 10, Steel C (mass%)
C
0.12-0.40
0.13-0.40
0.18
Si
0.01-1.5
≤ 1.5
0.95
Mn
More than 1.7 – 3.5
1.8-4.0
3.15
P
≤ 0.05
≤ 0.02
0.003
S
≤ 0.01
≤ 0.001
0.0004
Sol. Al
≤ 1.00
≤ 0.2
0.04
N
≤ 0.01
≤ 0.006
0.0029
B
0.0002-0.005
0.0003-0.0035
0.0019
Nb
Nb + Ti: 0.01-0.08
0.002-0.035 (one or two of Nb and Ti)
0.015
Ti
Nb + Ti: 0.01-0.08
0.002-0.04 (one or two of Nb and Ti)
0.01
Nb + Ti
0.01-0.08
> 0.007
0.025
At least one selected from the group:
One or more of: Cr, Mo, V, Zr, W
One or more of: Ca, Ce, La, Mg
One or two of Cu and Ni
One or two of Sb and Sn
Mo
≤ 0.350
0.01-0.5
0.07
Cr
≤ 0.350
0.01-1.0
-
Zr
≤ 0.350
0.005-0.2
-
Ca
≤ 0.0050
0.0002-0.003
-
V
≤ 0.50
0.003-0.5
-
W
≤ 0.20
0.005-0.2
-
Cu
≤ 1.00
0.005-1.0
-
Ni
≤ 1.00
0.01-1.0
-
Sb
≤ 0.10
0.002-0.1
-
Sn
≤ 0.10
0.002-0.1
-
Mg
≤ 0.01
-
REM
≤ 0.01
-
O: ≤ 0.002
O: 0.0008
Fe
Balance (“and incidental impurities”)
Balance (“and unavoidable impurities”)
Balance
Martensite
≥ 70 area %
Martensite + bainite: more than 90 area% to 100%
89 area% (calculated from subtracting B=9 from M+B=98)
Bainite
≤ 30 area %
Preferably 1-25 area %
9 area%
Ferrite
Ferrite + retained austenite: ≤ 10 area%
Remainder
Examples: 0-4 area%
0 area%
Retained austenite
Ferrite + retained austenite: ≤ 10 area%
Remainder
Preferably <5 area%
2 area%
Tensile strength
≥ 1310 MPa
1320-2000 MPa
1515 MPa
Carbide size
Long axes ≥ 0.5 μm
0.30-2 μm major axis
Broader disclosure
Carbide density
≤ 60000 carbides/mm2
≤ 4000 pieces/mm2
Carbide A: 200 particles/mm2
Inclusion size
≥ 4.0 μm equivalent circle diameter
Inclusion particles: ≥ 0.3 μm major axis ([0034], [0037])
Inclusion cluster A: major axis ≥ 100 μm ([0119])
Inclusion cluster B: major axis 20-100 μm ([0131])
Shortest distance between inclusion particles:
A: ≤ 30 μm ([0125])
B: ≤ 10 μm ([0132])
Broader disclosure
Inclusion density in 1/4-3/4 thickness region
10-30 grains/mm2
Inclusion cluster B: ≤ 5 clusters/mm2 ([0028])
5 clusters/mm2 (equivalent to ~10-50 grains/mm2 – see explanation below)
Inclusion density in a surface to 1/4 thickness region
≤ 27 grains/mm2
Inclusion cluster A: ≤ 2 clusters/mm2 ([0028])
0 clusters/mm2 (equivalent to 0-1 grains/mm2)
Hasegawa teaches a steel (Example 10, Steel C, Tables 1-2) with a chemical composition, microstructure, tensile strength, carbide size and density, and inclusion size and density lying inside the claimed ranges, as shown in List 1. In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Hasegawa therefore reads on the limitation a steel sheet having a tensile strength of 1310 MPa or higher, the steel sheet comprising: a chemical composition containing, in terms of mass%, C: 0.12% or more and 0.40% or less, Si: 0.01% or more and 1.5% or less, Mn: more than 1.7% and 3.5% or less, P: 0.05% or less, S: 0.010% or less, sol. Al: 1.00% or less, N: 0.010% or less, B: 0.0002% or more and 0.0050% or less, at least one selected from Nb and Ti: 0.010% or more and 0.080% or less in total, and the balance being Fe and incidental impurities; and a steel microstructure containing martensite at an area ratio of 70% or more, bainite at an area ratio of 30% or less, and ferrite and retained austenite at a total area ratio of 10% or less of claim 8 and wherein the chemical composition further includes, in terms of mass%, at least one selected from the group consisting of: Mo: 0.350% or less, Cr: 0.350% or less, Zr: 0.350% or less, Ca: 0.0050% or less, V: 0.500% or less, W: 0.200% or less, Cu: 1.00% or less, Ni: 1.00% or less, Sb: 0.100% or less, Sn: 0.100% or less, Mg: 0.01% or less, and REM: 0.01% or less of claim 9.
Additionally or alternatively, Hasegawa teaches a broader disclosure with a steel with a chemical composition ([0051]-[0111]), microstructure ([0113]-[0115]), tensile strength ([0169]), carbide size and density ([0029]), and inclusion size and density ([0028], [0034], [0037]) overlapping with the claimed steel, as shown in List 1.
Regarding the inclusions of claim 8, while Hasegawa does not explicitly teach an equivalent circle diameter, one of ordinary skill in the art would reasonably expect the inclusion particles to have equivalent circle diameters of 4.0 μm or more, given the major axis of the inclusion particles of Hasegawa is 0.3 μm or more. Hasegawa teaches the number densities of inclusion clusters A and B were measured in a cross section which is ⅕ thickness to ⅘ thickness below the surface layer of the steel sheet ([0154], thickness overlaps with claimed in a 1/4-to-3/4 thickness region of the steel sheet and claimed surface-to-1/4 thickness region of the steel sheet).
Hasegawa therefore reads on the limitation in a 1/4-to-3/4 thickness region of the steel sheet inclusion grains having equivalent circle diameters of 4.0 μm or more of claim 8 and in a surface-to-1/4 thickness region of the steel sheet inclusion grains having equivalent circle diameters of 4.0 μm or more of claim 8.
Regarding the inclusion densities of claim 8, Hasegawa teaches inclusion cluster densities rather than inclusion particle densities. However, one can calculate approximate inclusion particles contained in a cluster to obtain inclusion particle densities of Hasegawa given the broader disclosure of Hasegawa. Hasegawa teaches inclusion clusters are constitute by or more inclusion particles and that the inclusion particles in clusters A and B have a major axis of 0.3 μm or more ([0034], [0037]). Hasegawa teaches inclusion cluster A has a major axis of 100 μm or more ([0033]) and inclusion cluster B has a major axis of 20 μm or more and less than 100 μm ([0036]). Hasegawa further teaches that the shortest distance between inclusion particles in cluster A is 30 μm or less ([0034]) and 10 μm or less in cluster B ([0037]). Given the teachings of Hasegawa, one can approximate the number of inclusion particles per cluster by dividing the cluster major axis by the shortest distance between inclusion particles. For inclusion cluster A, a major axis of 100 μm divided by a distance between particles of 30 μm results in 3.33 inclusion particles per cluster. For inclusion cluster B, a major axis of 20-100 μm divided by a distance between particles of 10 μm results in 2-10 inclusion particles per cluster. Therefore, a density of 5 clusters/mm2 for inclusion cluster B results in a density of 10-50 particles/mm2, which overlaps with the claimed range as shown in List 1.
In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Hasegawa therefore reads on the limitation in a 1/4-to-3/4 thickness region of the steel sheet, a number density of inclusion grains having equivalent circle diameters of 4.0 μm or more is 10 grains/mm2 or more and 30 grains/mm2 or less, and in a surface-to-1/4 thickness region of the steel sheet, a number density of inclusion grains having equivalent circle diameters of 4.0 μm or more is 27 grains/mm2 or less of claim 8.
Additionally, or alternatively, regarding the inclusion size and density of claim 8, since the steel of Hasegawa has a chemical composition, microstructure, tensile strength, carbide size and density, and bendability overlapping with the claimed steel, one of ordinary skill in the art would reasonably expect the steel of Hasegawa to necessarily possess the claimed inclusion sizes and densities. Furthermore, Hasegawa teaches heating a slab at a temperature higher than 1220°C for 100 minutes or more (claim 24) using an average heating rate of 5-15°C/min ([0174]-[0175], 5-15°C/min is equivalent to 0.083-0.25°C/s).
Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP § 2112.01 I. “Products of identical chemical composition can not have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112.01 II. Therefore, it is expected that the steel of the prior art possesses the properties as claimed in the instant claims since a) the claimed and prior art products are identical or substantially identical in composition (see compositional analysis above), b) the claimed and prior art products are identical or substantially identical in structure (see microstructure analysis above), and c) the claimed and prior art products are produced by identical or substantially identical processes (both have slab heating with overlapping temperatures and heating rates). Since the Office does not have a laboratory to test the reference alloy, it is applicant’s burden to show that the reference alloy does not possess the properties as claimed in the instant claims. See In re Best, 195 USPQ 430, 433 (CCPA 1977); In re Marosi, 218 USPQ 289, 292-293 (Fed. Cir. 1983); In re Fitzgerald et al., 205 USPQ 594 (CCPA 1980).
Regarding the carbides of claim 8, Hasegawa teaches carbide size and densities lying within or overlapping with the claimed range as described above, and as shown in List 1. Hasegawa further teaches that the distribution density of carbides is measured in an L-cross section which is ¼ the thickness of the steel sheet below the surface in the thickness direction ([0159]).
Hasegawa therefore reads on the limitation wherein: at a 1/4 thickness position of the steel sheet, a number density of carbides having long axes of 0.5 μm or more is 60000 carbides/mm2 or less of claim 8.
Hasegawa therefore reads on all limitations of claims 8-9.
Regarding claims 10 and 11, Hasegawa teaches the steel sheet of claims 8 and 9 as described above.
Hasegawa teaches wherein the steel sheet has a coating layer deposited on the surface thereof (claim 8, [0172]).
Hasegawa therefore reads on the limitation wherein a coating layer is disposed on a surface of the steel sheet of claims 10 and 11.
Regarding claim 24, Hasegawa teaches the steel sheet of claim 8 as described above.
Hasegawa teaches bending the steel sheet with a bend radius that satisfied R/t=4.0, where R represents the bend radius and t represents the thickness of the steel sheet ([0216]). In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Hasegawa teaches reducing the occurrence of cracking at the sheared end surfaces in a high-strength steel having a TS of 1320 MPa or more by reducing the distribution density of the above-described inclusion clusters ([0127]). Therefore, one of ordinary skill in the art would reasonably expect the R/t=4.0 bend of Hasegawa to not generate cracks.
Hasegawa therefore reads on the limitation wherein an R/t value of the steel sheet is 4.0 or less, in which R is a minimum bending radius that does not generate cracks and t is a sheet thickness of claim 24.
Additionally or alternatively, Hasegawa teaches a sheet thickness of 0.5-2.6 mm and achieving a bending angle of 90 degrees or more with a bend radius of 5 mm or less ([0166]-[0167], R/t using a bend radius of 5 mm and thicknesses of 0.5-2.6 mm results in R/t values of 1.92-10 which overlap with the claimed range).
Response to Arguments
Applicant's arguments filed 04/15/2026 have been fully considered but they are not persuasive.
Applicant argues that the overlapping ranges standard set forth in MPEP 2144.05(1) and 2145 is not applicable when analyzing limitations that the Office acknowledges are not disclosed in the cited prior art (remarks, pages 2-3, emphasis in original text). Applicant argues that the Office has not sufficiently demonstrated that the steel sheets and manufacturing processes of Applicant and Hasegawa are substantially identical, such that Features (i) in a 1/4-to-3/4 thickness region of the steel sheet, a number density of inclusion grains having equivalent circle diameters of 4.0 μm or more is 10 grains/mm2 or more and 30 grains/mm2 or less and (ii) in a surface-to-1/4 thickness region of the steel sheet, a number density of inclusion grains having equivalent circle diameters of 4.0 μm or more is 27 grains/mm2 or less would be expected to naturally result from Hasegawa's disclosure (remarks, pages 2-4).
In response, Applicant’s argument suggests that Hasegawa is entirely silent regarding any inclusion size. However, Hasegawa explicitly teaches an inclusion size when teaching the inclusion particles have a major axis of 0.3 μm or more in paragraphs [0034] and [0037]. Describing an inclusion size in terms of major axes rather than the claimed equivalent circle diameter is merely a difference in description of the inclusion size. Hasegawa teaches an inclusion size with overlapping ranges despite differences in terminology. Additionally, or alternatively, since the steel of Hasegawa has a chemical composition, microstructure, tensile strength, carbide size and density, and bendability overlapping with the claimed steel, one of ordinary skill in the art would reasonably expect the steel of Hasegawa to necessarily possess the claimed inclusion sizes and densities. Absent any clear and convincing evidence and/or arguments to the contrary, one of ordinary skill in the art would expect the steel of Hasegawa to possess the claimed properties. A prima facie case of obviousness has been properly established herein. As the Patent Office does not possess the laboratory facilities to test any differences in the claimed invention versus that of the reference, the burden shifts to applicant to demonstrate otherwise.
Applicant argues that controlling the number density of inclusion grains having equivalent circle diameters of >4.0 μm in the specified region to 10 grains/mm2 or more and 30 grains/mm2 or less is critical to achieve both suppressed edge cracking and sufficient bendability (remarks, pages 5-7). Applicant argues that since Hasegawa fails to control the amount of inclusion particles to be within Applicant's required range, Hasegawa's steel sheet would not be expected to achieve both suppressed edge cracking and sufficient bendability (remarks, pages 6-7). Applicant argues that as Hasegawa fails to control its number density of inclusion particles of Feature (ii) to be within Applicant's required range, Hasegawa's steel sheet would not be expected to achieve sufficient bendability (remarks, pages 7-8).
In response, Hasegawa explicitly teaches bending the steel sheet with a bend radius that satisfied R/t=4.0, where R represents the bend radius and t represents the thickness of the steel sheet ([0216], one of ordinary skill in the art understands R/t ratios are a measurement used to evaluate bendability of a steel; R/t ratio overlaps with the claimed range of instant claim 24). Hasegawa further teaches reducing the occurrence of cracking at the sheared end surfaces in a high-strength steel having a TS of 1320 MPa or more by reducing the distribution density of the above-described inclusion clusters ([0127]). One of ordinary skill in the art would reasonably expect the R/t=4.0 bend of Hasegawa to reduce (and thereby suppress) cracks.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., both suppressed edge cracking and sufficient bendability) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Furthermore, Hasegawa explicitly teaches the claimed R/t value of instant claim 24 and therefore an identical bendability to the claimed steel.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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Any inquiry concerning this communication or earlier communications from the examiner should be directed to MAYELA ALDAZ whose telephone number is (571)270-0309. The examiner can normally be reached Monday -Thursday: 10 am - 7 pm and alternate Friday: 10 am - 6 pm.
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/M.A./Examiner, Art Unit 1733
/REBECCA JANSSEN/Primary Examiner, Art Unit 1733
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