DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/30/2025 has been entered.
Claim Status
An amendment, filed 12/30/2025, is acknowledged. Claim 1 is amended; Claim 3 is canceled; Claims 18-22 are newly added. Claims 1 and 4-22 are currently pending.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1, 4-15, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Nakagaito et al. (US 2011/0198002)(previously cited) alone or in the alternative, in view of Saito (US 2009/0277547).
With respect to Claims 1 and 13-14, Nakagaito teaches a steel sheet with a composition, in weight%, as follows (para. 11, 17-28):
Claim 1
Nakagaito
C
0.13-0.22
0.05-0.5
Si
1.2-1.8
0.01-2.5
Mn
1.8-2.2
0.5-3.5
Mo
0.10-0.20
Optionally, 0.005-2.0
Nb
≤ 0.05
Optionally, 0.01-0.20
Ti
< 0.05
Optionally, 0.01-0.20
Al
≤ 0.5
0.010-0.5
Fe
Balance with unavoidable impurities
Balance with unavoidable impurities
Other
-
P: 0.003-0.100
Compositional ranges including zero (e.g. Nb, Ti, and Al) are interpreted as optional elements. Thus, Nakagaito teaches a steel sheet with compositional ranges overlapping each of the instantly claimed ranges. The reference also teaches wherein the steel sheet has a structure comprising 5-20% retained/residual austenite, 60-95% total of tempered martensite (note, the instantly claimed steel is disclosed to undergo a partitioning treatment, see [0022], and thus, constitutes tempered martensite), and may be free of ferrite and optionally includes bainite. (para. 9, 29-34). The claim limitation “sum of martensite and bainite” is interpreted to require one or both of martensite and bainite such that the total meets the claimed range. While Nakagaito discloses the structure in area%, one of ordinary skill in the would recognize that the structure under a volume% analysis would be the same or substantially the same. Thus, Nakagaito is deemed to teach a steel sheet with compositional and microstructural ranges overlapping each of the claimed ranges.
It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Furthermore, Nakagaito teaches a steel sheet with a tensile strength of 1200 MPa or more, elongation of 13% or more, and hole expansion ratio of 50% or more, including examples with a tensile strength up to 1454 MPa, elongation of 17%, and hole expansion ratio up to 70%. (para. 7; Tables 4-5).
While Nakagaito does not specifically teach a hole expansion ratio measured under “ISO standard 16630:2009,” one of ordinary skill in the art would expect that, despite potential differences in standardized testing measurements, the measured property under such differing standards would nevertheless result in strongly correlating values. As Nakagaito teaches a hole expansion ratio that greatly exceeds the required value, it is deemed to establish a prima facie case of obviousness meeting the claimed limitation.
Additionally, While Nakagaito is silent as to yield strength, one of ordinary skill in the art would recognize that a steel having a higher tensile strength would be expected to have a higher yield strength. Here, the reference teaches a tensile strength exceeding the instantly claimed range, including examples that significantly exceed the required minimum tensile strength. As a result, even if the ratio of yield strength to tensile strength of the prior art differed somewhat from the claimed ratio, it would nevertheless be expected to possess a yield strength overlapping the instantly claimed range.
Moreover, Nakagaito teaches a method of making a steel sheet substantially similar to that instantly disclosed and as Applicant admits, is important to obtaining the claimed combination of structure and properties. Namely, Applicant points to the specification requiring a cooling rate higher than 30°C/s from the annealing temperature. (see Remarks, dated 10/21/2024, p. 6)(see also [0022] reciting “quenching the sheet by cooling down to a quenching temperature QT lower than the Ms transformation point at a cooling rate enough to avoid ferrite and bainite formation”). Nakagaito teaches a method of making the steel sheet comprising cooling from the annealing temperature at a rate of 20-200°C/s to a temperature 100-200°C below the Ms point, teaching that this cooling temperature is critical to achieving the claimed microstructure, which meets the claimed microstructural ranges. (para. 37-39).
Accordingly, Nakagaito teaches a steel sheet with substantially overlapping composition, microstructure, tensile strength, elongation, and hole expansion ratio values which significantly exceed the claimed minimum values and which is made by a method substantially similar to that instantly disclosed and admitted by Applicant as resulting in a steel with the claimed properties. As a result, one of ordinary skill in the art would expect that the steel sheet of Nakagaito would necessarily result in a steel having the same structure and properties, including overlapping microstructural ranges, a yield strength meeting or overlapping the claimed range, and a hole expansion ratio, when measured under the claimed standard, meeting or overlapping the claimed range. See MPEP 2112.01.
"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, 195 USPQ 430, 433 (CCPA 1977). Thus, the burden is shifted to the applicant to prove that the product of the prior art does not necessarily or inherently possess the characteristics attributed to the claimed product. See In re Spada, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990) (“When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not."); MPEP 2112.01. Therefore, the prima facie case can only be rebutted by evidence showing that the prior art products do not necessarily possess the characteristics of the claimed product.
Finally, with respect to the average grain or block size limitation of claim 1 and of claims 13-14, Nakagaito teaches that the steel sheet has austenite grains having a “very small size,” (para. 36) but is silent as to the specific average grain size martensite, bainite, and austenite/residual austenite.
As Nakagaito teaches a steel sheet with substantially overlapping composition, microstructure, properties and which is made by a method substantially similar to that instantly disclosed (see further discussion above), one of ordinary skill in the art would expect that the steel sheet of Nakagaito would necessarily result in a steel having the same structure and properties, including the claimed martensite, austenite, and bainite average grain/block size. See MPEP 2112.01. It is further noted that as Claim 1 does not specifically require a content of bainite, Nakagaito which is optionally free of bainite, also meets the limitation of claims 1 and 14 when the bainite content is zero.
In the alternative, Saito teaches a high strength and high hole expansion ratio steel sheet having compositional ranges of C, Si, Mn, Al, Nb, Ti, and Mo overlapping those of Nakagaito and the instant claims, the steel exhibiting a microstructure comprising 50-95% martensite, 5-30% bainite, 10% or less residual austenite, and wherein the mean grain size of the martensite is 10 microns or less and the mean grain size of residual austenite is 20 microns or less. (para. 16-18, 22, 41-45, 188). Saito teaches “[w]hen the grain size is larger than 10 μm in terms of the equivalent of a circle diameter, elongation and stretch-flanging performance are lowered. For this reason, the upper limit is 10 μm.” (para. 44).
Thus, Nakagaito and Saito are both drawn to high strength steel sheets having microstructures with a martensitic primary phase and drawn to shared utilities including high strength, elongation, and hole expansion ratio. It would have been obvious to one of ordinary skill in the art to control the average martensite grain size to 10 μm or less, as taught by Saito, in order to maintain good elongation and stretch-flanging properties. Further, it would have been obvious to one of ordinary skill in the art to minimize the residual austenite and/or bainitic average grain sizes, in the same manner, in order to improve or maintain the desired mechanical properties of the steel sheet. It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. MPEP § 2144.05.
With respect to Claims 4-12, Nakagaito teaches a steel with microstructural ranges, compositional ranges, and property values meeting or overlapping each of the instantly claimed ranges. (see rejection of claim 1 above). Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claims 15 and 17, as discussed with respect to Claim 1 Nakagaito teaches a steel sheet having a structure comprising 60-95% total of tempered martensite (note, the instantly claimed steel is disclosed to undergo a partitioning treatment, see [0022], and thus, constitutes tempered martensite). (para. 9, 29-34). While Nakagaito discloses the structure in area%, one of ordinary skill in the would recognize that the structure under a volume% analysis would be the same or substantially the same. Thus, Nakagaito is deemed to teach a steel sheet with a content of martensite overlapping the ranges of claims 15 and 17, respectively. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claims 21-22, Nakagaito or Nakagaito in view of Saito teach a steel sheet meeting each of the instantly claimed limitations. (see rejection of claim 1 above). In particular, Claim 21 differs only in the claimed yield strength. As Nakagaito teaches a steel sheet with substantially overlapping composition, microstructure, properties and which is made by a method substantially similar to that instantly disclosed (see further discussion above), one of ordinary skill in the art would expect that the steel sheet of Nakagaito would necessarily result in a steel having the same yield strength. See MPEP 2112.01.
Claim(s) 1, 6-15, 18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Hammer (US 2015/0203946).
With respect to Claims 1, 12-14, 18, and 20, Hammer teaches a steel sheet with a composition, in weight%, as follows (para. 13-25):
Claim 1
Hammer
C
0.13-0.22
0.10-0.60
Si
1.2-1.8
0.4-2.0
Mn
1.8-2.2
0.4-2.5
Mo
0.10-0.20
0-0.4
Nb
≤ 0.05
0-0.2
Ti
< 0.05
0-0.2
Al
≤ 0.5
0-2.0
Fe
Balance with unavoidable impurities
Balance with unavoidable impurities
Compositional ranges including zero (e.g. Nb, Ti, and Al) are interpreted as optional elements. Thus, Hammer teaches a steel sheet with compositional ranges overlapping each of the instantly claimed ranges. The reference also teaches wherein the steel sheet has a structure comprising, by volume, at least 50% bainite, 0-10% martensite, 0-5% ferrite, and remainder residual austenite, wherein the residual austenite has blocks with a mean diameter of less than 5 microns. (para. 25). Thus, Hammer teaches a steel sheet with compositional and microstructural ranges overlapping each of the claimed ranges of claims 1 and 18, respectively.
It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Furthermore, Hammer teaches a steel sheet with a tensile strength of 1200 MPa or more, elongation of 17% or more, and examples having a tensile strength exceeding 1180 MPa and yield strength exceding 850 MPa. (para. 37; Table 3).
While Hammer is silent as to a hole expansion ratio as instantly claimed, as the reference teaches a steel sheet with substantially overlapping composition, microstructure, tensile strength, yield strength, and elongation, one of ordinary skill in the art would expect that the steel sheet of Hammer would necessarily result in a steel having the same structure and properties, including a hole expansion ratio, when measured under the claimed standard, meeting or overlapping the claimed ranges of claims 1, 12, and 18, respectively. See MPEP 2112.01.
"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, 195 USPQ 430, 433 (CCPA 1977). Thus, the burden is shifted to the applicant to prove that the product of the prior art does not necessarily or inherently possess the characteristics attributed to the claimed product. See In re Spada, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990) (“When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not."); MPEP 2112.01. Therefore, the prima facie case can only be rebutted by evidence showing that the prior art products do not necessarily possess the characteristics of the claimed product.
Finally, with respect to the average grain or block size limitation of claim 1 and of claims 13-14, Hammer teaches that the steel sheet has austenite grains/blocks have a size of less than 5 microns in order to improve elongation properties. (para. 25, 32, 34). While the reference is silent as to the grain size of the martensite and bainite, it would have been obvious to one of ordinary skill in the art forming a steel with minimized average grain size of one constituent phase to, at the same time, minimize the grain size of the remaining constituent microstructural phases as processes for refining grain size (e.g. working, heat treatments) are applied to the sheet as a whole. Accordingly, it would have been obvious to one of ordinary skill in the art to form the steel sheet of Hammer having average grain/block size of the martensite and bainite phases of 5 microns or less, in order to improve the mechanical properties of the steel sheet.
With respect to Claims 6-11, Hammer teaches a steel with compositional ranges and property values meeting or overlapping each of the instantly claimed ranges. (see rejection of claim 1 above). Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
With respect to Claim 15, Hammer teaches up to 10 vol% martensite falling within the claimed range of “at most 65% martensite.” (see rejection of claim 1 above).
Allowable Subject Matter
Claim 19 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the prior art of record fails to teach a steel sheet meeting each of the claim limitations of claim 18 and further exhibiting a yield strength of at least 978 MPa.
Claims 21-22 are allowed.
The following is an examiner’s statement of reasons for allowance: the prior art of record fails to teach a steel sheet meeting each of the claim limitations of claim 21, in particular, differing from claim 1 in that it requires a yield strength of at least 978 MPa. The instant specification provides sufficient evidence to demonstrate that a steel sheet having the claimed combination of composition, content of martensite, bainite, residual austenite, no ferrite content, tensile strength of 1180 MPa or more, hole expansion ratio as instantly claimed, would not necessarily achieve the claimed yield strength. (instant specification, Table 1).
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Response to Arguments
Applicant's arguments filed 12/30/2025 have been fully considered but they are not persuasive.
Applicant argues that prior art Nakagaito fails to teach “the martensite and the bainite consist of grains or blocks having an average size of 10 μm or less.” Applicant points to alleged differences in the disclosed methods of making, such as a broader partitioning temperature range, to argue that Nakagaito would not inherently result in the claimed grain size. These arguments have been fully considered but are not found persuasive.
Nakagaito teaches a steel sheet with substantially overlapping composition, microstructure, tensile strength, elongation, and hole expansion ratio values which significantly exceed the claimed minimum values and which is made by a method substantially similar to that instantly disclosed and admitted by Applicant as resulting in a steel with the claimed properties. As a result, one of ordinary skill in the art would expect that the steel sheet of Nakagaito would necessarily result in a steel having the same structure and properties, including the claimed average martensite and bainite grain/block size. See MPEP 2112.01 ("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, 195 USPQ 430, 433 (CCPA 1977). Thus, the burden is shifted to the applicant to prove that the product of the prior art does not necessarily or inherently possess the characteristics attributed to the claimed product.”)
The instant specification, while providing certain comparative evidence, fails to provide sufficient evidence, commensurate with the scope of the claims, to rebut the teachings of Nakagaito and therefore, the rejection is maintained. Specifically, the evidence present in the specification does not include any comparative examples with respect to average grain size of martensite, bainite, or residual austenite.
Applicant again argues that “Nakagaito does not render obvious the composition recited in claim 1.” (Remarks, p. 7). These arguments have previously been addressed and are not found persuasive.
Applicant attempts to formulate a new standard of evaluating compositions wherein individual element compositional overlaps, in the form of percentages, are multiplied into an “Overall overlap.” Applicant provides no reasonable basis for this formulation and it is not supported by the MPEP nor the cited case law. Moreover, Applicant’s comparisons are based on assumptions that are not required by the claims and prior art. For example, the claimed ranges of Nb and Ti each include zero and therefore, may be considered optional elements. Nakagaito also teaches Nb and Ti as optional elements. Therefore, the ranges of Nb and Ti could alternatively be interpreted as 100% overlap. Nakagaito teaches a composition with ranges having with a level of overlap one of ordinary skill in the art would find reasonable and Applicant’s arguments misconstrue the teachings of the prior art and the standard of obviousness. Additionally, Applicant provides no evidence, commensurate with the scope of the claims, to demonstrate criticality or unexpected results of the compositional ranges. As a result, Applicant fails to rebut the prima facie case of obviousness.
Applicant again argues that because the hole expansion ratio of the prior art was not measured using the same standardized methodology, the values cannot be compared and concludes that Nakagaito cannot disclose the claimed feature. These arguments have been fully considered but are not found persuasive.
As detailed in the rejection, one of ordinary skill in the art would expect that, despite potential differences in standardized testing measurements, the measured property under such differing standards would nevertheless result in strongly correlating values. As Nakagaito teaches a hole expansion ratio that greatly exceeds the required value, it is deemed to establish a prima facie case of obviousness meeting the claimed limitation. Applicant incorrectly concludes that these teachings do not shift the burden of proof to Applicant and Applicant provides no evidence to distinguish the measurement methodologies, nor any evidence to rebut the prima facie case of obviousness. Applicant instead, merely concludes that, despite drawn to the same property, different measurements techniques disqualify the teachings of the prior art. These arguments are not found persuasive.
Applicant provides no new arguments with respect to a yield strength of 850 MPa and therefore, the argument is not found persuasive.
Finally, the non-statutory double patenting rejection over App. No. 18/009790 is withdrawn in view of Applicant’s amendments to the claims.
Conclusion
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/JOHN A HEVEY/Primary Examiner, Art Unit 1735