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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 March 9, 2026 has been entered.
Response to Amendment and Status of Claims
Applicant’s amendments to the claims, filed March 9, 2026, are acknowledged. Claim 1 is amended. No new matter has been added.
Claims 1-3 are pending and currently 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.
Claims 1-2 are rejected under 35 U.S.C. 103 as being unpatentable over Murakami (previously cited, US 20150170812 A) in view of Uesaka (previously cited, US 20160012948 A1), Ushigami (previously cited, US 20020038678 A1) and Inokuti (US 20030180554 A1).
Regarding Claim 1, Murakami discloses a method for manufacturing a grain-oriented electrical steel sheet (Abstract) comprising:
heating a slab (para. [0015]; para. [0066]), which contains, in terms of mass%:
Element
Claim 1
Murakami
Citation
Table 1, no. 1-4, [0066]
C
0.0001-0.100
0.025-0.075
[0015]
0.05%
Si
0.80-7.00
2.5-4.0
[0015]
3.2%
Mn
0.05-1.00
0.03-0.30
[0015]
0.1%
Sol. Al
0.001-0.0700
0.01-0.06
[0015]
0.03%
N
0.004-0.0120
0.001-0.013
[0015]
0.01%
Seq*
S+0.406*Se = 0.003-0.0150
0.001-0.02 S; opt. 0.0005-0.02 Se
[0015]; [0034]
0.01% S, 0% Se,
Seq = 0.01
Cr
0-0.30
0.002-0.20
[0034]
0%
Cu
0-0.40
0.002-0.40
[0034]
0.02%
Sn
0-0.30
0.02-0.20
[0015]
0.006%
Sb
0-0.30
0.002-0.20
[0034]
0%
P
0-0.50
0.01-0.08
[0015]
0.026%
B
0-0.0080
0.0005-0.02
[0034]
0%
Bi
0-0.0100
0.0005-0.02
[0034]
0%
Ni
0-1.00
0.002-0.20
[0034]
0%
Fe, impurities
remainder
remainder
[0015]
remainder
One of ordinary skill in the art would appreciate that the S range of Murakami, and the optional inclusion and range of Se of Murakami, reads on and overlaps the claimed Seq values. When Se is included in Murakami, the Seq of Murakami would range from 0.0012-0.028, which overlaps the claimed range of 0.003-0.015. When Se is absent from Murakami, the Seq range of Murakami is 0.001-0.02, which also overlaps and reads on the claimed range of 0.003-0.015.
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.
Murakami further discloses heating the slab to lower than 1250°C and subjecting the steel slab to hot rolling to obtain a hot-rolled steel sheet (para. [0052]; para. [0066], 1150°C).
performing hot-band annealing on the hot-rolled steel sheet (para. [0054], one of ordinary skill in the art would appreciate the annealing directly after hot-rolling to be hot-band annealing; para. [0067]),
pickling the hot-rolled steel sheet which has been subjected to the hot-band annealing (para. [0067]), and
subjecting the hot-rolled steel sheet which has been subjected to the pickling to cold rolling to obtain a cold-rolled sheet (para. [0067]; para. [0055]).
Murakami discloses hot rolling to a thickness of 1.8-3.5mm and cold rolling with 85-92% reductions (para. [0053] and para. [0057]). Thus, while Murakami does not expressly disclose cold rolling to a final sheet thickness d of 0.15-0.21 mm, the hot-rolling thicknesses and cold rolling reductions would overlap the claimed range. For example, a 2.0mm (see 1.8-3.5mm range) hot rolled sheet which has been cold rolled with a reduction ratio of 90% (see 85-92% reduction range), would produce a final sheet thickness of 0.20mm, which reads on the claimed range.
Further, Uesaka teaches cold rolling to a final thickness of 0.15-0.23mm in order to produce an extremely-thin grain-oriented electrical steel sheet which has a decreased eddy current loss (para. [0002]; para. [0004], wherein thickness reductions decrease eddy current loss; para. [0014], wherein it is conventional to make the sheet thickness thinner to reduce eddy current loss). Uesaka further teaches that this range of final cold-rolling thickness balances the driving force of secondary recrystallization and dispersion of Goss orientations with increases in the ratio of the insulation coating and the decreases in magnetic flux density (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 cold rolled the steel sheet of Murakami to a final thickness of 0.15-0.23mm, which reads on the claimed 0.15-0.21mm thickness, as taught by Uesaka, in order to make an extremely-thin grain-oriented electrical steel sheet with reduced eddy current loss, while balancing the driving force of secondary recrystallization and dispersion of Goss orientations with increases in the ratio of the insulation coating and decreases in magnetic flux density (see teachings above).
Murakami further discloses performing a decarburization nitriding treatment including decarburization annealing and nitriding on the cold-rolled steel sheet (para. [0060]; para. [0067]),
wherein in decarburization annealing temperature in the decarburization annealing is lower than 1000°C (para. [0058], 800-950C; para. [0067], 860°C),
performing final annealing on the cold-rolled steel sheet which has been subjected to the decarburization nitriding treatment (para. [0060]-[0061]; para. [0067]), and
applying a coating liquid for insulation coating formation to the cold-rolled steel sheet which has been subjected to the final annealing and baking the coating liquid (para. [0061]; para. [0068]).
Murakami discloses 0.010-0.060% sol. Al and 0.0010-0.0130% N (para. [0044]-[0045]), and Uesaka discloses thicknesses of 0.15-0.23mm (see teaching above and Uesaka, para. [0014]). Therefore, while Murakami is silent towards a relationship between the ratio of sol. Al/N and the final cold-rolled thickness of the steel sheet, Murakami and Uesaka disclose amounts of sol. Al/N and cold rolling thicknesses which overlap and satisfy the claimed expression 4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84.
For example, the invention of Uesaka and Murakami include a steel comprising 0.03% sol. Al and 0.01% N (see Murakami, para. [0066]), and a steel sheet cold rolled to a final thickness of 0.20mm (see Uesaka, para. [0032]). These amounts of sol. Al and N, and cold rolled thickness, satisfies the claimed relationship (see -4.17*(0.2)+3.63 ≤ [0.03/0.01] ≤ -3.10*0.2+4.84 which equates to 2.796 ≤ 3 ≤ 4.22).
Further, Uesaka additionally teaches controlling the Al/N ratio in order to uniformly and stably produce secondary recrystallization in thinner sheets according to their thickness, thereby obtaining uniform and very low iron loss over the full length of a coil (para. [0014]-[0015]; para. [0017]). Uesaka teaches wherein 4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32 is satisfied in order to achieve this effect, which overlaps the ranges defined by the claimed expression 4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84 for final cold rolled thicknesses of 0.16mm or greater (see table below; Uesaka, para. [0018]; para. [0043]-[0045]). For example, the table below demonstrates the sol. Al/N ratio taught by Uesaka for cold rolled thickness of 0.16-0.21mm (thicknesses also taught by Uesaka – see above) as compared the ratios required by Claim 1.
Final cold-rolled thickness
Sol. Al/N as defined by recited relationship, respectively
d (mm)
Claim 1* (exp. 1)
Uesaka* (Abstract)
overlap
0.16
2.16-2.96
2.96-5.34
2.96
0.17
2.92-5.37
2.2-3.0
2.92-3.0
0.18
2.88-5.40
2.24-3.04
2.88-3.04
0.19
2.84-5.43
2.28-3.08
2.84-3.08
0.20
2.80-5.46
2.32-3.12
2.80-3.12
0.21
2.75-5.49
2.36-3.16
2.75-3.16
*calculated sol. Al/N for different thicknesses according to the claimed relationship (4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84) and the relationship disclosed by Uesaka (4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the sol. Al/N ratio to be within the range of 4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32, which reads on and overlaps the claimed ratio range of 4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84 (see table above), as taught by Uesaka, for the invention disclosed by Murakami and Uesaka, in order to obtain uniform and very low iron loss over the full length of a coil (see teachings above).
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.
Murakami and Uesaka are silent towards an oxidation degree of an annealing atmosphere in the decarburization annealing, and do not disclose an oxidation degree of 0.01 or more to less than 0.15.
Ushigami teaches an oxidation index (degree) in decarburization of 0.01-0.15 in order to not form Fe oxides within the temperature range of 770-900C while balancing for decarburization rate (para. [0047]; Claim 9; para. [0113]; see para. [0058] of Murakami, wherein decarburization annealing occurs within the range of 800-950C).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used an oxidation degree of 0.01-0.15, as taught by Ushigami, for the invention disclosed by Murakami, in order to not form Fe oxides during decarburization while balancing for decarburization rate (see teaching above).
Murakami is silent towards the N content of the cold-rolled steel sheet which has been subjected to the decarburization nitriding treatment, and fails to disclose a nitrogen content of 40 to 1000 ppm. However, the composition (for example, see para. [0066] and composition table above), the heat treatment parameters and particularly the decarburization and nitriding parameters (para. [0066]-[0068]; see teaching by Ushigami above regarding oxidation index during decarburization), and the final cold rolling sheet thickness (para. [0047] and para. [0053]; see teachings by Uesaka above), are the same as the instant invention, and it would be expected that the N content of the cold-rolled steel sheet of Murakami which has been subjected to the decarburization nitriding treatment comprise a N content of 40-1000ppm, as claimed.
When 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.I.
Further, Uesaka teaches wherein the sol. Al/N ratio relationship is still satisfied or even adjusted to be satisfied after a nitriding treatment (para. [0045]). Thus, Uesaka requires values of N after nitriding which read on and overlap the claimed range of 40-1000ppm (0.004-0.1%). For example, for a 0.20mm cold-rolled sheet comprising 0.02% sol. Al (see Murakami, para. [0015], 0.01-0.06% sol. Al; see Uesaka para. [0032], wherein sheet is cold-rolled to 0.20mm and comprises 0.02% sol. Al), Uesaka teaches a content of N after nitriding to be within the range 0.006-0.0086% N (60-86ppm) in order to satisfy the relationship 4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32, which overlaps the claimed amount of N after decarburization nitriding annealing of 40-1000ppm.
Thus, 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 nitrogen content after decarburization nitriding treatment and before secondary recrystallization (final annealing) which satisfies the required sol. Al/N ratio relationship taught by Uesaka (4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32, wherein d is the final cold-rolled thickness), and therefore one which reads on 40-1000ppm N, for the invention disclosed by Murakami and Uesaka. One would be motivated to do this in order to realize the effects of the sol. Al/N ratio taught by Uesaka, wherein the grain-oriented electrical steel sheet comprises a uniform and very low iron loss over the full length of a coil (see para. [0017]; para. [0044]; and teachings by Uesaka above).
Murakami does not disclose an 17/50 iron loss of 0.61 W/kg.
However, the composition of Murakami and Uesaka, and the processing of Murakami, Uesaka and Ushigami are the same as claimed, and it would be obvious to one of ordinary skill in the art that the steel of Murakami, Uesaka and Ushigami result in the claimed core loss. When 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.I.
Further, Ushigami further teaches obtaining an 17/50 iron (core) loss as low as 0.62 W/Kg through securing a low {111}/{411} texture ratio (Table 18, iron loss values as low as 0.62 W/kg). Ushigami teaches low core loss properties are desired for electrical components such as transformers (para. [0002]).
Additionally, Inokuti teaches forming a pre-coating of TiNO followed by a layer of SiN prior to baking on an insulating coating of phosphate and silica, thereby improving adhesion property of the coating and improving iron loss, achieving a reduction in W17/50 by up to 0.15W/Kg as compared to without the multi-layer tension coating, and iron loss values as low as 0.49 W/kg (Abstract; para. [0048]-[0051]; para. [0057]; para. [0001]; see also comparison of [0053]-[0055], wherein TiN coating alone only achieves 0.68W/kg; para. [0126]; para. [0152]). Inokuti teaches wherein these coatings allow for no deterioration in iron loss during stress relief annealing (para. [0007]; Abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have obtained an 17/50 iron (core) loss as low as 0.62 W/Kg, such as by reducing the {111}/{411} texture ratio, as taught by Ushigami, and further to have applied the tension coating layers of Inokuti, thereby obtaining a further 0.15W/Kg reduction of W17/50 iron loss, and iron loss values as low as 0.49 W/Kg, as taught by Inokuti, for the invention disclosed by Murakami. One would be motivated to do this in order to obtain an ultra-low iron loss grain oriented silicon steel sheet which comprises improved coating adhesion and magnetic properties which do not deteriorate upon stress relief annealing (see teaching by Inokuti above), and obtain a steel sheet with maximized core loss capable for use in a transformer (see teaching above).
Regarding Claim 2, Murakami discloses wherein the steel slab contains, in terms of mass%, one or more of:
Element
Claim 2
Murakami
Citation
Cr
0.02-0.30
0.002-0.20
[0034]
Cu
0.10-0.40
0.002-0.40
[0034]
Sn
0.02-0.30
0.02-0.20
[0015]
Sb
0.02-0.30
0.002-0.20
[0034]
P
0.02-0.50
0.01-0.08
[0015]
B
0.001-0.008
0.005-0.02
[0034]
Bi
0.0005-0.01
0.0005-0.02
[0034]
Ni
0.02-1.00
0.002-0.20
[0034]
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.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Murakami (previously cited, US 20150170812 A) in view of Uesaka (previously cited, US 20160012948 A1), Ushigami (previously cited, US 20020038678 A1) and Inokuti (US 20030180554 A1), as applied to Claim 1 above, in further view of Song (previously cited, US 20200017930 A1).
Regarding Claim 3, Murakami does not disclose wherein the hot band annealing occurs in two stages, and fails to disclose the limitations of Claim 3.
Song discloses hot band annealing (annealing of the hot-rolled steel prior to cold rolling) which occurs in two temperature stages, wherein the first stage temperature is within the range of 850-1150C in order maximize phase transformation between austenite and ferrite, and to re-dissolve coarse and non-uniform precipitates, and a second temperature stage within the range of 850-950C in order to finely and reliability re-precipitate the precipitates which were re-dissolved in the first soaking step/first temperature stage, thereby reducing the number of edge cracks to occur during cold rolling (para. [0056]; para. [0063]-[0066]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have hot band annealed the steel sheet of Murakami, such that the hot band annealing is performed so that the hot rolled steel sheet is heated to a first stage temperature 850-1150C, which reads on the claimed 1000-1150C, and then annealed at 850-950C, which reads on the claimed 850-1100C and lower than the first stage temperature, as taught by Song. One would be motivated to use these hot band annealing steps in order to maximize phase transformation between austenite and ferrite, re-dissolve coarse and non-uniform precipitates, and then finely and reliability re-precipitate the precipitates which were re-dissolved in the first soaking step/first temperature stage, thereby reducing the number of edge cracks to occur during cold rolling (see teachings above by Song).
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.
Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Song (previously cited, US 20200017930 A1) in view of Uesaka (previously cited, US 20160012948 A1), Ushigami (previously cited, US 20020038678 A1) and Inokuti (US 20030180554 A1).
Regarding Claim 1, Song discloses a method for manufacturing a grain-oriented electrical steel sheet (Abstract) comprising:
heating a slab (para. [0032]), which contains, in terms of mass%:
Element
Claim 1
Song
Citation
Example 1 (para. [0082])
C
0.0001-0.100
>0 to 0.1
[0034]
0.06%
Si
0.80-7.00
2.00-6.00
[0034]
3.3%
Mn
0.05-1.00
>0 to 0.20
[0034]
0.011%
Sol. Al
0.001-0.0700
>0 to 0.05
[0034]
0.004%
N
0.004-0.0120
>0 to 0.01
[0034]
0.005%
Seq*
S+0.406*Se = 0.003-0.0150
>0 to 0.01 S; 0% Se (silent)
[0034]
Seq= 0.005% - see 0.005% S and 0% (silent) Se
Cr
0-0.30
0.003-0.10
[0051]
0.06%
Cu
0-0.40
0% (silent)
0% (silent)
Sn
0-0.30
0.003-0.10
[0051]
0.08%
Sb
0-0.30
0.003-0.10
[0051]
0.03%
P
0-0.50
>0 to 0.08
[0034]
0.03%
B
0-0.0080
0.003-0.10
[0051]
0% (silent)
Bi
0-0.0100
0% (silent)
0% (silent)
Ni
0-1.00
0.003-0.10
[0051]
0% (silent)
Fe, impurities
remainder
remainder
[0034]
remainder
One of ordinary skill in the art would appreciate that the S range of Song equates to the claimed Seq because Song is silent towards Se, and one of ordinary skill in the art would appreciate Se to be 0% in Song.
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.
Song further discloses heating the slab to lower than 1250°C and subjecting the steel slab to hot rolling to obtain a hot-rolled steel sheet (para. [0053], 1050-1250C; para. [0082], 1150C),
performing hot-band annealing on the hot-rolled steel sheet (para. [0056], one of ordinary skill in the art would appreciate the annealing directly after hot-rolling and before cold rolling to be hot-band annealing; para. [0082]),
pickling the hot-rolled steel sheet which has been subjected to the hot-band annealing (para. [0082]), and
subjecting the hot-rolled steel sheet which has been subjected to the pickling to cold rolling to obtain a cold-rolled sheet having a final sheet thickness d of 0.15-0.21 mm (para. [0069], 0.1-0.70mm reads on the claimed 0.15-0.21mm),
performing a decarburization nitriding treatment including decarburization annealing and nitriding on the cold-rolled steel sheet (para. [0060]; para. [0067]),
wherein in decarburization annealing temperature in the decarburization annealing is lower than 1000°C (para. [0071]-[0072], 950C or less; para. [0082], 850C),
wherein the N content of the cold-rolled sheet which has been subjected to the decarburization nitriding treatment is 40 to 1000ppm (para. [0082], 180 ppm),
performing final annealing on the cold-rolled steel sheet which has been subjected to the decarburization nitriding treatment ([0073]; para. [0083], secondary recrystallization), and
applying a coating liquid for insulation coating formation to the cold-rolled steel sheet which has been subjected to the final annealing and baking the coating liquid (para. [0077]; one of ordinary skill in the art would appreciate that the insulating film would be applied as a liquid and then baked, as is well-known and common in the art; see para. [0075] of Uesaka for example).
Song discloses up to 0.050% sol. Al and up to 0.01% N, and steel thicknesses which range from 0.1-0.7mm (para. [0034]; para. [0069]). Therefore, while Song is silent towards a relationship between the ratio of sol. Al/N and the final cold-rolled thickness of the steel sheet, Song disclose amounts of sol. Al/N and cold rolling thicknesses which overlap and satisfy the claimed expression 4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84.
For example, the invention of Song include a steel comprising 0.015% sol. Al and 0.005% N (para. [0039], up to 0.04% sol. Al; para. [0047], up to 0.01% N), and a steel sheet cold rolled to a final thickness of 0.20mm (0.20mm is within the 0.1-0.7mm range of Song – para. [0069]). These amounts of sol. Al and N, and cold rolled thickness, satisfies the claimed relationship (see -4.17*(0.2)+3.63 ≤ [0.015/0.005] ≤ -3.10*0.2+4.84 which equates to 2.796 ≤ 3.0 ≤ 4.22).
Further, Uesaka teaches cold rolling to a final thickness of 0.15-0.23mm in order to reduce current loss, and to balance the driving force of secondary recrystallization and dispersion of Goss orientations with increases in the ratio of the insulation coating and decreases in magnetic flux density (para. [0002]; para. [0004] and para. [0014], wherein thickness reductions decrease eddy current loss; para. [0060]).
Uesaka additionally teaches controlling the Al/N ratio in order to uniformly and stably produce secondary recrystallization in thinner sheets according to their thickness, thereby obtaining uniform and very low iron loss over the full length of a coil (para. [0014]-[0015]; para. [0017]). Uesaka teaches wherein 4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32 is satisfied in order to achieve this effect, which overlaps the ranges defined by the claimed expression 4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84 for final cold rolled thicknesses of 0.16mm or greater (see table below; Uesaka, para. [0018]; para. [0043]-[0045]).
The table below demonstrates the sol. Al/N ratio taught by Uesaka for cold-rolled thicknesses of 0.16-0.21mm as compared to the ratios required by Claim 1.
Final cold-rolled thickness
Sol. Al/N as defined by the recited relationship, respectively
d (mm)
Claim 1* (exp. 1)
Uesaka* (Abstract)
overlap
0.16
2.16-2.96
2.96-5.34
2.96
0.17
2.92-5.37
2.2-3.0
2.92-3.0
0.18
2.88-5.40
2.24-3.04
2.88-3.04
0.19
2.84-5.43
2.28-3.08
2.84-3.08
0.20
2.80-5.46
2.32-3.12
2.80-3.12
0.21
2.75-5.49
2.36-3.16
2.75-3.16
*calculated sol. Al/N for different thicknesses according to the claimed relationship (4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84) and the relationship disclosed by Uesaka (4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have cold rolled the steel sheet of Song to a final thickness of 0.15-0.23mm, which reads on the claimed 0.15-0.21mm thickness, and to have modified the sol. Al/N ratio to be within the range of 4d+1.52 ≤ [Sol.Al/N] ≤ 4d+2.32, which reads on and overlaps the claimed ratio range of 4.17*d+3.63 ≤ [Sol.Al/N] ≤ -3.10*d+4.84 (see table above), as taught by Uesaka. One would be motivated to do this in order to reduce eddy current loss, while balancing the driving force of secondary recrystallization and dispersion of Goss orientations with increases in the ratio of the insulation coating and decreases in magnetic flux density (see teachings above for cold rolled thicknesses), and in order to obtain uniform and very low iron loss over the full length of a coil (see teachings above for sol. Al/N ratio).
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.
Song is silent towards an oxidation degree of an annealing atmosphere in the decarburization annealing, and do not disclose an oxidation degree of 0.01 or more to less than 0.15.
Ushigami teaches an oxidation index (degree) in decarburization of 0.01-0.15 in order to not form Fe oxides within the temperature range of 770-900C while balancing for decarburization rate (para. [0047]; Claim 9; para. [0113]; see para. [0071] of Song, wherein decarburization annealing occurs at 950C or less).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used an oxidation degree of 0.01-0.15, as taught by Ushigami, for the invention disclosed by Song, in order to not form Fe oxides during decarburization while balancing for decarburization rate (see teaching above).
Song does not disclose an 17/50 iron loss of 0.61 W/kg.
However, the composition of Song and Uesaka, and the processing of Song, Uesaka and Ushigami are the same as claimed, and it would be obvious to one of ordinary skill in the art that the steel of Song, Uesaka and Ushigami result in the claimed core loss. When 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.I.
Further, Ushigami further teaches obtaining an 17/50 iron (core) loss as low as 0.62 W/Kg through securing a low {111}/{411} texture ratio (Table 18, iron loss values as low as 0.62 W/kg). Ushigami teaches low core loss properties are desired for electrical components such as transformers (para. [0002]).
Additionally, Inokuti teaches forming a pre-coating of TiNO followed by a layer of SiN prior to baking on an insulating coating of phosphate and silica, thereby improving adhesion property of the coating and improving iron loss, achieving a reduction in W17/50 by up to 0.15W/Kg as compared to without the multi-layer tension coating, and iron loss values as low as 0.49 W/kg (Abstract; para. [0048]-[0051]; para. [0057]; para. [0001]; see also comparison of [0053]-[0055], wherein TiN coating alone only achieves 0.68W/kg; para. [0126]; para. [0152]). Inokuti teaches wherein these coatings allow for no deterioration in iron loss during stress relief annealing (para. [0007]; Abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have obtained an 17/50 iron (core) loss as low as 0.62 W/Kg, such as by reducing the {111}/{411} texture ratio, as taught by Ushigami, and further to have applied the tension coating layers of Inokuti, thereby obtaining a further 0.15W/Kg reduction of W17/50 iron loss, and iron loss values as low as 0.49 W/Kg, as taught by Inokuti, for the invention disclosed by Song. One would be motivated to do this in order to obtain an ultra-low iron loss grain oriented silicon steel sheet which comprises improved coating adhesion and magnetic properties which do not deteriorate upon stress relief annealing (see teaching by Inokuti above), and obtain a steel sheet with maximized core loss capable for use in a transformer (see teaching above).
Regarding Claim 2, Song discloses wherein the steel slab contains, in terms of mass%, one or more of:
Element
Claim 2
Song
Citation
Cr
0.02-0.30
0.003-0.10
[0051]
Cu
0.10-0.40
Sn
0.02-0.30
0.003-0.10
[0051]
Sb
0.02-0.30
0.003-0.10
[0051]
P
0.02-0.50
0.003-0.10
[0051]
B
0.001-0.008
0.003-0.10
[0051]
Bi
0.0005-0.01
Ni
0.02-1.00
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.
Regarding Claim 3, Song discloses wherein hot band annealing (annealing of the hot-rolled steel prior to cold rolling) is performed so that the hot-rolled steel is heated to 1000-1150C, which is a first stage temperature, and then annealed at 850-1100C and lower than the first stage temperature (para. [0056]; para. [0063]-[0066]; see para. [0082], first stage heating at 1060C, second stage heating at 900C).
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.
Response to Arguments
Applicant’s arguments, filed March 9, 2026, with respect to Claim 1, and dependent Claims thereof, rejected under 35 U.S.C. 103 over Murakami in view of Uesaka and Ushigami, and over Song in view of Uesaka and Ushigami, have been fully considered and are persuasive in view of Applicant’s amendments to the claims further limiting the iron loss. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made under 35 U.S.C. 103 over Murakami in view of Uesaka, Ushigami and Inokuti, and over Song in view of Uesaka, Ushigami and Inokuti, as detailed above.
Regarding the Iron Loss:
Applicant argues that Murakami and Song do not disclose the claimed iron loss, and there is no motivation to reduce the iron loss to be within the claimed range.
This argument is not found persuasive.
Firstly, the composition and manufacturing method of Murakami, Uesaka and Ushigami, and the composition and manufacturing method of Song, Uesaka, and Ushigami, are the same as the claimed invention. Therefore, one of ordinary skill in the art would appreciate the steel to comprise the claimed iron loss.
Secondly, one of ordinary skill in the art would be motivated to further achieve superior magnetic properties, which includes a reduction in iron loss. One would be motivated to obtain as low an iron loss value as possible for a higher quality steel sheet and the subsequent product which uses the steel sheet, such as a transformer, as taught by Ushigami.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Imamura (previously cited, WO 2018084198 A1, with US 20190323100 as English Equivalent): teaches an overlapping hot-rolling and cold-rolling method of producing a grain oriented steel using a similar composition (Abstract; para. [0068]-[0070]; para. [0082]; para. [0086]-[0090]; para. [0054]-[0064]).
Gabor (previously cited, US 20150155085 A): teaches pickling after hot-band annealing in order to remove oxide layers and secondary scale residues (para. [0079]).
Zhou (previously cited, “Effect of sulfur and acid soluble aluminum content on precipitate and microstructure of grain-oriented Silicon Steel”): teaches the modifying the amount of sol. Al to precipitate AlN, thereby retarding banding structures , reducing grain growth during recrystallization, and promoting secondary recrystallization, and therefore allowing for more uniform and smaller grain sizes (pg. 1707-1708, Conclusion).
Inokuchi (previously cited, US 4,702,780): teaches 0.005-0.06% sol. Al to precipitate AlN which acts as an inhibitor, and to balance grain growth during secondary recrystallization (Col. 4, lines 30-44).
Uesaka (previously cited and cited above, US 20160012948 A1, further teachings): teaches wherein S+Se exist in a total amount of 0.01-0.05% (Abstract).
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/CATHERINE P SMITH/Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735
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