DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 March 27, 2026 has been entered. Claims 1-2, and 4-8 are pending with claims 5-8 remaining withdrawn as directed to non-elected subject matter.
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.
Claims 1-2 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Fujita et al. (KR20110105403, references herein made to the English translation dated March 11, 2025).
Regarding applicants’ claim 1, Fujita et al. disclose a cold-rolled steel sheet comprising in wt. %: C: not more than 0.025%, Si: not more than 0.1%, Mn: 0.05 to 0.5%, P: not more than 0.03%, S: not more than 0.02%, sol.Al: 0.01 to 0.1%, Ti: 0.002 to 0.05%, Nb: 0.002 to 0.05%, B: 0.0001 to 0.005% (paragraphs 0024-0042). Regarding the nitrogen content Fujita et al. provide for exemplary steel sheets having a nitrogen content ranging from 0.0012 to 0.0025 wt.% (Table 1). One of ordinary skill in the art would expect the nitrogen content in the cold-rolled steel sheet to be within the range of the exemplary steel sheets disclosed by Fujita et al.
Fujita et al. do not appear to explicitly disclose the exact compositional ranges claimed including values resulting in a reinforcement index of the exact range of 1.0 to 3.0, however the compositional proportions disclosed overlap those claimed, including values which result in a reinforcement index within the claimed range. One of ordinary skill in the art before the effective filing date of the inventions would have found it obvious to select from the disclosed compositional proportions, including proportions which fall within the claimed range, and which result in a reinforcement index which falls within the claimed range.
Fujita et al. disclose an average ferrite grain size of 15µm or less (paragraph 0050), but do not appear to explicitly disclose a recrystallization ratio, an average grain diameter, or a grain aspect ratio as claimed, however one of ordinary skill in the art would expect substantially identical materials treated in a substantially identical manner to have substantially identical structures. In addition to the compositional proportions discussed above, Fujita et al. disclose a process of manufacturing the cold-rolled steel sheet substantially identical to that disclosed by applicants.
Applicants disclose a hot-rolling step with a finishing temperature of Ar3 or higher, coiling at 600 to 700ºC, cold-rolling at a reduction ratio of 20.0 to 60.0% and annealing the cold-rolled steel sheet at a temperature of 400.0 to 580.0ºC (page 16 line 10 – page 18 line 20).
Fujita et al. disclose hot-rolling with a finishing temperature of Ar3 or higher, coiling at 500 to 650ºC, cold rolling at a reduction ratio that is preferably 30% or more and 75% or less, and annealing at 500 or 600ºC depending on the addition of Nb or Ti (paragraphs 0053-0064).
Given substantially identical materials treated in a substantially identical manner, the cold-rolled steel sheet of Fujita et al. would be expected to have a substantially identical structure to the cold-rolled steel sheet disclosed by applicants, including having a recrystallization ratio, dislocation density, and grain aspect ratio within, or at least overlapping, applicants’ claimed range.
Regarding applicants’ claim 2, Fujita et al. disclose that the steel comprises niobium at 0.002 to 0.05 wt.% which overlaps applicants’ claimed range of 0.01 wt.% or less. One of ordinary skill in the art before the effective filing date of the invention would have found it obvious to select from the proportions disclosed by Fujita et al. including values which fall within the presently claimed range.
Regarding applicants’ claim 4, Fujita et al. disclose plating of the cold-rolled steel sheet (paragraph 0065). When plated one or both sides of the sheet would include a plating as required.
Response to Arguments
Applicants’ arguments filed March 27, 2025 have been considered but have not been found to be persuasive.
While the examiner has taken the position that substantially identical materials would possess substantially identical properties, applicants argue that when some conditions are different not all of the parameters of their invention are satisfied. Specifically, applicants argue that the cold-rolling reduction ratio is critical in obtaining the claimed dislocation density. However the reduction ratio disclosed in the prior art substantially overlaps applicants’ disclosed reduction ratio where applicants disclose a reduction ratio of 20 to 60% and where Fujita et al. disclose 30 to 75% or less (as discussed in the rejections above). Once a reference teaching a product appearing to be substantially identical is made the basis of a rejection and the examiner presents evidence or reasoning to show inherency the burden of production shifts to the applicant. "[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of his [or her] claimed product. Whether the rejection is based on ‘inherency’ under 35 U.S.C. 102, on ‘prima facie obviousness’ under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same." MEPE 2112 V. While a showing of unexpected results may be the basis for establishing non-obviousness, the amount of cold-working is known to be associated with the density of dislocations. Saito et al. (US PGPub 2017/0051377) for example disclose s a steel sheet where cold rolling is used to increase the density of dislocations, and where the higher reduction ratios lead to greater dislocation densities (paragraph 0059). Given that the cold-rolling reduction ratio is known to affect the dislocation density applicants have not established that the effect argued is of both unexpected and of statistical and practical significance (MPEP 716.02(b)). For these reasons there is insufficient evidence that applicants’ claimed dislocation density range produces a steel sheet which exhibits unexpectedly improved properties, and the rejections over Fujita et al. are maintained.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ADAM C KRUPICKA whose telephone number is (571)270-7086. The examiner can normally be reached Monday-Friday 8-5pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Humera Sheikh can be reached at (571)272-0604. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Adam Krupicka/Primary Examiner, Art Unit 1784
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