DETAILED ACTION
Response to Amendment
The Amendment filed 05 August 2026 has been entered. Claims 1-5 remain pending in the application. No new claim(s) have been added.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted between 23 October 2023 and 28 January 2026 were considered by the examiner. The submission is in compliance with the provisions of 37 CFR 1.97.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 3, 4, and 5 are rejected under 35 U.S.C. 103 as being unpatentable over JP2019178373A (machine translation) of Hama in view of US20190189318A1 of Uesaka and KR102026271B1 (machine translation) of Lee.
Claim 1 claims a non-oriented electrical steel sheet comprising: by wt%, 2.5 to 4.0% of Si, 0.1 to 1.5% of Al, 0.1 to 1.5% of Mn, and the remainder of Fe and inevitable
impurities, wherein an average grain size is 50 to 100 µm, and an area ratio of grains having a grain size of 20 µm or less is 0.5% or more, and wherein the average grain size and the area ratio of grains are measured based on a face parallel to a cross section (TD face) in the vertical direction of rolling.
Hama teaches a non-oriented electromagnetic steel sheet and manufacturing method therefor, and motor core and manufacturing method therefor in the same field of endeavor as the claimed invention. Hama discloses a range for Si: 1.0 to 5.0 wt%, Al: 0 to 2.0%, Mn: 0.10 to 2.0%, with the balance containing Fe and impurities, Para[0011]. These ranges overlap with the claimed ranges. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Hama also discloses that the area ratio occupied by crystal grains having an equivalent circle diameter of 30 μm or less on the surface of the steel sheet is SA, and SA ≧ 15%, Para[0016]. This overlaps with the claimed range of 20 µm or less and 0.5% or more. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Hama does not teach a specific range for average grain size.
Uesaka teaches a non-oriented electrical steel sheet and method for manufacturing non-oriented electrical steel sheet in the same field of endeavor as the claimed invention. Uesaka discloses that an average grain size of 40 μm to 120 μm, can reduce the iron loss both under sinusoidal excitation and under inverter excitation, Para[0121]. Therefore, it would be obvious to one of ordinary skill in the art to produce the non-oriented electrical steel sheet taught by Hama with the average grain size disclosed by Uesaka to reduce iron loss.
Lee teaches a non-oriented electrical steel sheet and method for manufacturing the same in the same field of endeavor as the claimed invention. Lee teaches that non-oriented electrical steel sheet according to an embodiment of the present invention may have an average grain size of 70 to 150㎛, Para[0066]. This overlaps with the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Lee discloses that in the aforementioned range, the magnetism of the non-oriented electrical steel sheet is more excellent, Para[0066], and that the grain size was calculated by (measurement area / number of grains) ^ 0.5 by photographing an area including 1500 or more grains in the TD cross section of the specimen under an optical microscope, Para[0094]. Therefore, it would be obvious to one of ordinary skill in the art to incorporate the average grain size of Lee, measured in a cross section in the TD direction, to the steel sheet of Hama in order to improve the magnetism. Thus, Hama in view of Uesaka and Lee covers all limitations of claim 1.
Claim 3 further limits claim 1 by further comprising: 0.005 wt% or less of at least one of C, N, S, Ti, Nb, and V.
Hama teaches a range for carbon of C: 0.0005 to 0.0050%, and nitrogen of N: 0.0010 to 0.0050%, Para[0012]. This overlaps with the claimed range of 0.005% or less. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Thus, Hama in view of Uesaka and Lee covers all limitations of claim 3.
Claim 4 further limits claim 1 by further comprising: at least one of 0.05 wt% or less of P, 0.002 wt% or less of B, 0.01 wt% or less of Mo, 0.005 wt% or less of Mg, and 0.005 wt% or less of Zr.
Hama discloses a range for phosphorus of P: 0.0200% or less, and magnesium of Mg: 0 to 0.10%. These overlap with the claimed ranges for P and Mg. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Thus, Hama in view of Uesaka and Lee covers all limitations of claim 4.
Claim 5 further limits 1 by claiming that yield strengths YS (- 40°C) and YS (210°C) obtained when tensile tests are performed at – 40°C and 210°C satisfy YS (210°C)/YS (- 40°C)? 0.71.
While Hama, Uesaka and Lee do not specifically teach yield strength, they disclose a non-oriented electrical steel sheet with overlapping ranges for all the claimed elemental ranges. 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, see MPEP 2112.01. Yield strength is an intrinsic property of an alloy determined by the alloy composition. Thus, Hama in view of Uesaka and Lee covers all limitations of claim 5.
Claims 2 is rejected under 35 U.S.C. 103 as being unpatentable over JP2019178373A (machine translation) of Hama in view of US20190189318A1 of Uesaka and KR102026271B1 (machine translation) of Lee., as applied to claim 1 above, further in view of JP2017082276A (machine translation) of Fujimura.
Claim 2 further limits claim 1 by further comprising: 0.006 to 0.1 wt% of at least one of Sn and Sb.
Hama teaches Sn: 0 to 0.20 %, Para[0039]. This overlaps with the claimed range for Sn. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05.
Lee teaches that Tin (Sn), antimony (Sb), and phosphorus (P) segregate on the surface or grain boundary of the base material to lower the surface energy and grain boundary energy, thus delaying the inhibition of precipitates, recrystallization of {111} <uvw>, and developing an advantageous texture for magnetism. Even if one element of Sn, Sb, P is less than 0.005% by weight, the effect may be significantly reduced. If any one element of Sn, Sb, P exceeds 0.1% by weight, the segregation amount is excessive, brittleness increases and the surface quality decreases, which causes a limitation in commercial production. The above-mentioned effect can be most clearly seen when the total content of Sn, Sb, and P is contained in the range of 0.025 to 0.20% by weight. More specifically, the total content of Sn, Sb, and P may be 0.05 to 0.15 wt%, Para[0054]. This overlaps with the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05.
Fujimura teaches a non-oriented electromagnetic steel sheet and manufacturing method therefor in the same field of endeavor as the claimed invention. Fujimura discloses ranges for Sn and Sb of 0.005 to 0.2%, Para[0009]. This overlaps with the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, see MPEP 2144.05. Fujimura teaches that it is an object of the present invention to provide a method of producing Sb and Sn by adding Sb and Sn to a base steel sheet in order to reduce high frequency iron loss, Para[0008].
Therefore, based on the teachings of Hama, Lee and Fujimura, it would be obvious to include Sn and Sb in the claimed range to the non-oriented electrical steel sheet disclosed by Hama in view of Uesaka in order to reduce high frequency iron loss and develop an advantageous texture for magnetism. Thus, Hama in view of Lee and Uesaka further in view of Fujimura covers all limitations of claim 2.
Response to Arguments
Applicant's arguments filed 05 August 2026 have been fully considered but they are not persuasive. Applicant argues that (remarks, page 6 of 7) secondary reference Uesaka does not disclose the claimed grain size feature since Uesaka measures its average grain size on a cross-section parallel to the rolling direction. This argument is moot, as the new grounds of rejection necessitated by amendment relies upon KR102026271B1 (machine translation) of Lee for its teachings of average grain size. Lee discloses that the grain size was calculated by (measurement area / number of grains) ^ 0.5 by photographing an area including 1500 or more grains in the TD cross section of the specimen under an optical microscope, Para[0094]. Therefore, the average grain size of Lee applied to the sheet of Hama would cover the claimed invention.
Applicant argues that (remarks, page 6 of 7) Hama and Uesaka employ different manufacturing methods than the claimed invention and therefore wouldn’t cover the claimed invention. Applicant then describes the differences in the annealing processes of the claimed invention and the prior art. 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., annealing temperature and time) 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). Examiner asserts that it is equally possible for different preparation processes to obtain similar microstructures and grain sizes and that one of ordinary skill in the art would understand that the steel sheet of Hama, Uesaka, Lee and Fujimura meets the limitations of the claimed invention even if the annealing conditions are not the same.
Examiner’s Note
Examiner has attached the machine translation of previously-cited foreign references that were inadvertently omitted in the non-final action. References Included herein: JP2019178373A (machine translation) and JP2017082276A (machine translation)
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/JACOB BENJAMIN STILES/Examiner, Art Unit 1733
