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 .
Status of Claims
No amendments to the claims have been filed. Claim 3 remains withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, Group II, directed to a manufacturing method, there being no allowable generic or linking claim. Applicant timely elected in the reply filed March 19, 2024.
Claims 1 and 3 are pending, and Claim 1 is being considered in this office action.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Nippon (previously cited, JP 62039231 A, English Machine Translation provided) in view of Yamazaki (previously cited, US 20160060723 A1) and Nishiwaki (previously cited by Applicant in IDS filed June 26, 2024, JP H10130782 A, English Machine Translation provided).
Regarding Claim 1, Nippon discloses a gradient steel material having a high-plasticity surface layer and a high-strength inner layer (Abstract). One of ordinary skill in the art would appreciate a surface layer of 70% or more fine grained ferrite as a high-plasticity surface layer, and a center layer of mainly bainite to be a high-strength inner layer. One of ordinary skill in the art would appreciate that a microstructure comprising microstructures which vary from the surface to the center of the steel reads on the broadest most reasonable interpretation of gradient steel.
Nippon further discloses wherein the steel consists the following components in percentage by weight:
≤0.30% C (Abstract, para. [0018]-[0019]; reads on the claimed 0<C≤0.15%),
≤1.50% Si (Abstract, para. [0020], reads on the claimed 0<Si≤1.0%),
≤2.0% Mn (Abstract, para. [0021], reads on the claimed 0<Mn≤1.5%), and
the balance of Fe and inevitable impurities (Abstract; para. [0014]-[0015], wherein steel consists of C, Si, Mn, Fe and inevitable impurities).
Additionally, one of ordinary skill in the art would further appreciate that Al, N, S and P are described as inevitable impurities (para. [0022]-[0024]).
Nippon discloses wherein the surface layer of the steel material is 70% or more fine-grained ferrite, which is inclusive of 100% and therefore a surface layer consisting of ferrite, as claimed (Abstract; para. [0014]).
Regarding the compositional ranges and ferrite in the surface layer, 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). See MPEP § 2144.05.I.
Nippon also discloses wherein the central portion (inner layer) is mainly composed of one of bainite, and further, wherein the central portion may comprise some amounts of the fine-grained ferrite (Abstract; para. [0014]; para. [0039], wherein central part becomes partially fine ferrite; [0048], wherein fine ferrite grains are somewhat formed in the central portion and most of the remainder is bainite).
However, Nippon does not expressly disclose wherein the central portion (inner layer) consists of bainite and ferrite.
Yamazaki teaches a similar steel with surface regions being at least 80% or more ferrite, including 100%, and an inner region being mainly bainite phase in an amount of 90% or more with a remainder being one of ferrite phase in an amount up to 10% in order to achieve high strength while balancing for bending workability (para. [0012]-[0016]; para. [0057], wherein surface region is 100% ferrite; para. [0059]-[0061]; para. [0028]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have had a surface region consisting of 100% ferrite and an inner region of at least 90% bainite and a balance of up to 10% ferrite, and therefore an inner region consisting of bainite and ferrite, as taught by Yamazaki, for the invention disclosed by Nippon, in order to produce a hot-rolled steel with high strength while balancing for bending workability (see teaching by Yamazaki above).
Nippon is silent towards the carbon content in the ferrite surface layer and the carbon content in the inner layer of the steel material, and therefore is silent towards a surface layer comprising 0.02wt% of C or less, and a surface layer comprising a carbon content lower than a carbon content of the inner layer.
Nishiwaki discloses wherein the content of C in a surface layer is less than 0.05% in order to achieve a mainly ferrite microstructure in the surface (para. [0060]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have comprised a ferrite surface layer with a carbon content of 0.05% or less, and therefore 0.02% or less as claimed, as taught by Nishiwaki, for the invention disclosed by Nippon, in order to obtain a surface layer of consisting of a ferrite microstructure (see teaching above by Nishiwaki), as required by Nippon and Yamazaki.
Additionally, it would have been obvious that the ferrite surface layer in Nippon comprise a carbon content less than the mainly (at least 90%) bainite and 10% or less ferrite microstructure of the inner layer of Nippon and Yamazaki because there is less ferrite in the inner layer (and therefore more carbon by comparison), and one of ordinary skill in the art would appreciate that bainite comprises a higher carbon solubility limit than ferrite.
Claim 1 is alternatively rejected under 35 U.S.C. 103 as being unpatentable over Nippon (previously cited, JP 62039231 A, English Machine Translation provided) in view of Yamazaki (previously, US 20160060723 A1), Nishiwaki (cited by Applicant in IDS filed June 26, 2024, JP H10130782 A, English Machine Translation provided), and Takayama (previously cited, US 20050257860 A1).
Regarding Claim 1, Nippon discloses a gradient steel material having a high-plasticity surface layer and a high-strength inner layer (Abstract). One of ordinary skill in the art would appreciate a surface layer of 70% or more fine grained ferrite as a high-plasticity surface layer, and center layer of mainly bainite to be a high-strength inner layer. One of ordinary skill in the art would appreciate that microstructure comprising microstructures which vary from the surface to the center of the steel reads on the broadest most reasonable interpretation of gradient steel.
Nippon further discloses wherein the steel consists the following components in percentage by weight:
≤0.30% C (Abstract, para. [0018]-[0019]; reads on the claimed 0<C≤0.15%),
≤1.50% Si (Abstract, para. [0020], reads on the claimed 0<Si≤1.0%),
≤2.0% Mn (Abstract, para. [0021], reads on the claimed 0<Mn≤1.5%), and
the balance of Fe and inevitable impurities (Abstract; para. [0014]-[0015], wherein steel consists of C, Si, Mn, Fe and inevitable impurities).
Additionally, one of ordinary skill in the art would further appreciate that Al, N, S and P are described as inevitable impurities (para. [0022]-[0024]).
Nippon discloses wherein the surface layer of the steel material is 70% or more fine-grained ferrite, which is inclusive of 100% and therefore a surface layer consisting of ferrite, as claimed (Abstract; para. [0014]).
Regarding the compositional ranges and ferrite in the surface layer, 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). See MPEP § 2144.05.I.
Nippon also discloses wherein the central portion (inner layer) is mainly composed of one of bainite, and further, wherein the inner layer (central portion) may comprise some amounts of the fine-grained ferrite (Abstract; para. [0014]; para. [0039], wherein central part becomes partially fine ferrite; [0048], wherein fine ferrite grains are somewhat formed in the central portion and most of the remainder is bainite).
However, Nippon does not expressly disclose wherein the central portion (inner layer) consists of bainite and ferrite.
Yamazaki teaches a similar steel with surface regions being at least 80% or more ferrite, including 100%, and an inner region being mainly bainite phase in an amount of 90% or more with a remainder being one of ferrite phase in an amount up to 10% in order to achieve high strength while balancing for bending workability (para. [0012]-[0016]; para. [0057], wherein surface region is 100% ferrite; para. [0059]-[0061]; para. [0028]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have had a surface region consisting of 100% ferrite and an inner region of at least 90% bainite and a balance of up to 10% ferrite, and therefore an inner region consisting of bainite and ferrite, as taught by Yamazaki, for the invention disclosed by Nippon, in order to produce a hot-rolled steel with high strength while balancing for bending workability (see teaching by Yamazaki above).
Nippon is silent towards the carbon content in the ferrite surface layer and the carbon content in the inner layer of the steel material, and therefore is silent towards a surface layer comprising 0.02wt% of C or less, and a surface layer comprising a carbon content lower than a carbon content of the inner layer.
Nishiwaki discloses wherein the content of C in a surface layer is less than 0.05% in order to achieve a mainly ferrite microstructure in the surface (para. [0060]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have comprised a ferrite surface layer with a carbon content of 0.05% or less, and therefore 0.02% or less as claimed, as taught by Nishiwaki, for the invention disclosed by Nippon, in order to obtain a surface layer of consisting of a ferrite microstructure (see teaching above by Nishiwaki), as required by Nippon and Yamazaki.
Additionally, it would have been obvious that the ferrite surface layer in Nippon comprise a carbon content less than the mainly (at least 90%) bainite and 10% or less ferrite microstructure of the inner layer of Nippon and Yamazaki because there is less ferrite in the inner layer (and therefore more carbon by comparison), and one of ordinary skill in the art would appreciate that bainite comprises a higher carbon solubility limit than ferrite.
Further, Takayama teaches wherein a bainite phase comprises a solid solution of 0.07-0.3wt% C in order to decrease tensile residual stress during quenching (bainite phase formation), thereby increasing the strength of the base material and improving fatigue resistant strength (para. [0064]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have had 0.07-0.3wt% C in the 90% or more bainite phase of the inner layer portion of Nippon and Yamazaki, as taught by Takayama, and therefore a larger amount of C than in the ferrite surface layer as claimed, in order to comprise an inner layer with decreased tensile residual stresses and therefore increased strength and improved fatigue resistance (see teaching above).
Response to Arguments
Applicant’s arguments, filed June 24, 2025, with respect to Claim 1 rejected under 35 U.S.C. 103 over Nippon in view of Nishiwaki and Yamazaki (and Takayama, alternatively), have been fully considered, but are respectfully not found persuasive.
Regarding Nippon:
Applicant argues that Nippon forms distinct microstructures in the surface and inner layers, and argues that the microstructures of Nippon indicate a carbon content exceeding 0.022% (i.e., one which is not ferrite).
Applicant argues Nippon uses rolling, which is incapable of facilitating carbon migration and therefore Applicant argues there would inevitably be pearlite and bainite in the surface layer, and that Nippon cannot form a pure ferrite surface layer.
This argument is not found persuasive.
Nippon already discloses a range of 70% or more ferrite in the surface layer, which includes 100% ferrite, and reads on the claimed language consisting of. Further, Applicant provides no evidence that rolling would necessarily result in a microstructure comprising pearlite or bainite, and arguments of council cannot take place of evidence on the record. Additionally, the instant invention uses rolling (see instant specification, pg. 6), and Yamazaki, whom expressly teaches a surface layer of 100% ferrite (see para. [para. [0057]), also includes rolling (see Abstract, hot-rolled). Thus, one of ordinary skill in the art would be capable of forming a surface layer consisting of ferrite (and therefore one with the claimed C content) in the surface layer, despite using rolling. Regarding carbon migration, this is not a currently claimed feature and therefore not commensurate in scope with the claims.
Regarding Yamazaki: Applicant argues that Yamazaki requires Ti and V to achieve a 100% ferrite surface layer, and Nippon lacks these elements. Applicant argues that it would be nonobvious to therefore achieve a 100% ferrite surface layer in Nippon and that Yamazaki and Nippon have significant compositional differences such that the teaching would not have yielded the steel material of Claim 1.
Applicant argues that Yamazaki does not teach a working example comprising 100% ferrite in the surface layer and an inner region of only ferrite and bainite.
These arguments are not found persuasive.
Yamazaki teaches wherein the inclusion of Ti and V form carbonitrides and refine the bainite phase (para. [0040]-[0043]). Yamazaki does not correlate the presence of Ti and V with the ability to form the ferrite layer. Alternatively, Yamazaki teaches wherein carbon content contributes to the microstructure and the ferrite layer (para. [0030]), and further teaches wherein Si facilitates the formation of ferrite phase (para. [0034]). These elemental ranges overlap with Nippon (see Abstract of Nippon, up to 0.3% C, up to 1.5% Si; see Abstract of Yamazaki, 0.1-0.2% C, 0.5-3% Si). Thus, one of ordinary skill in the art would have an expectation of success of forming a 100% ferrite layer in the steel of Nippon through the teachings of Yamazaki.
Regarding working examples, Yamazaki expressly teaches “preferably 90% or more, or it may be 100% (which means a ferrite single phase)” (para. [0057]), and an inner region of “mainly a bainite phase in an amount of 90% or more and the balance being at least one selected from the group of a ferrite phase” (para. [0059]). Therefore, Yamazaki expressly teaches the claimed structure. Yamazaki does not need to provide a working example for the teaching to be valid. Patents are relevant as prior art for all they contain, and disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiment (see MPEP 2123 I&II).
Regarding Nishiwaki and Takayama:
Applicant argues that Nishiwaki discloses an inner layer consisting of primarily martensite and bainite, and does not mention ferrite. Applicant argues that the carbon content of Nishiwaki’s surface would not have acquired the surface and inner layer microstructures.
Applicant argues that Takayama discloses carbon content in its surface layer but this is for martensite. Applicant argues that Takayama discloses a different microstructure for the inner layer, and that these differences in the inner layer microstructure would prevent the teachings of Takayama from being applied to Nippon.
Applicant also argues that the steel of Takayama comprises a higher carbon content in the surface layer than the inner layer, and teaches away from the claimed invention.
These arguments are not found persuasive.
Neither Nishiwaki nor Takayama are applied to teach the inner microstructure consisting of ferrite and bainite, or the surface layer microstructure consisting of ferrite. The surface ferrite layer and the bainite and ferrite inner layer are already disclosed and taught by Nippon and Yamazaki. Rather, Nishiwaki and Takayama are applied to demonstrate the carbon contents which form the phases disclosed by Nippon and Yamazaki (i.e., the carbon content required for a phase to be ferrite and the carbon content found in bainite). Specifically, Nishiwaki is applied to demonstrate that a layer requires a carbon content of less than 0.05% in order to be ferrite, and Takayama is applied to teach that the bainite phase comprises 0.07-0.3% C, with the added benefit that this range of C in bainite of reduces tensile residual stresses during bainite formation and increases strength and fatigue resistance (see rejection above).
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Goto (previously cited and cited by Applicant in IDS filed June 17, 2021, WO 2018110152 A1, English Machine translation provided): Goto discloses a gradient steel material having a high-plasticity surface layer and a high-strength inner layer (Abstract, one of ordinary skill in the art would appreciate a surface layer of single phase ferrite as a high-plasticity surface layer, and center layer of ferrite and upper bainite to be a high-strength inner layer), comprising the following components in percentage by weight:
0<C≤0.15%, 0<Si≤1.0%, 0<Mn≤1.5%, and the balance of Fe and inevitable impurities (Abstract; para. [0056]-[0057]; Table 1, examples B, D, G, H and K), wherein
the surface layer of the steel material is ferrite, and the inner layer is ferrite and bainite (Abstract, wherein surface layer is single phase ferrite, and inner layer is ferrite and upper bainite; see also para. [0063], wherein center (inner layer) of the steel is 80-92% ferrite and 8-20% second phase and wherein the second phase is upper bainite; see para. [0065], wherein front and back surfaces (surface layer) is single phase ferrite).
Yamamoto (previously cited, US 3615278 A): teaches a steel comprising a ferrite surface layer with a carbon amount of 0.02% or less, and further an amount of carbon in the surface layer which is less than the carbon amount in the inner (core portion) layer, in order to produce a steel sheet which comprises excellent surface qualities for enamel grade steel and good cold workability (Col. 1, 20-22; Col. 2, lines 27-54; see also Col. 8, lines 24-31, wherein surface layer is ferrite and comprises a C amount of less than 0.025% C). Yamamoto further teaches, in addition to a ferrite surface layer, wherein the carbon solubility limit in ferrite is 0.02% (Col. 10, lines 50-53).
Suehiro (previously cited, JP 2001059129 A, English Translation provided): teaches a surface layer of 90% or more ferrite and an internal layer of 70% or more bainite in order to obtain a high yield stress while balancing for workability (Abstract; para. [0016).
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 nonprovisional extension fee (37 CFR 1.17(a)) 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CATHERINE P SMITH whose telephone number is (303)297-4428. The examiner can normally be reached Monday - Friday 9:00-4:00 MT.
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CATHERINE P. SMITH
Patent Examiner
Art Unit 1735
/CATHERINE P SMITH/Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735