DETAILED ACTION
Response to Amendment
The Amendment filed 03/17/2026 has been entered. Claims 10-23 remain pending in the application. Claims 18-23 have been withdrawn due to a restriction requirement. Claims 1-9 have been canceled. No new claims have been added. Claims 10-17 are presented for examination on the merits. Applicant's amendments to the abstract and specification have overcome the objections previously set forth in the Non-Final Rejection mailed 11/17/2025. Applicant's amendments to the claims have overcome the 112(b) rejections previously set forth in the Non-Final Rejection mailed 11/17/2025.
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 10-17 are rejected under 35 U.S.C. 103 as being unpatentable over WO 2019/132226 A1 of Kim (hereafter WO’226, with reference to its English machine translation).
Regarding claims 10-17, WO’226 teaches a lean duplex stainless steel having improved bending ability (Abstract, duplex stainless steel reads on the claimed dual phase stainless steel sheet since “duplex” is another term for “dual phase” in the steel arts). WO’226 teaches the duplex stainless steel has two phases, an austenite phase and a ferrite phase ([0001], [0069]-[0070], reads on the claimed dual phase stainless steel sheet containing an austenite and a ferrite).
List 1
Instant claims (mass%)
WO’226 (wt%)
C
≤ 0.080 (claims 10, 14-15)
≤ 0.030 (claims 12-13, 16-17)
≤ 0.08 (excluding 0)
Si
≤ 1.00 (claims 10, 14-15)
≤ 0.75 (claims 12-13, 16-17)
≤ 1 (excluding 0)
Mn
≤ 4.00 (claims 10, 14-15)
2.00-4.00 (claims 12-13, 16-17)
2-4
P
≤ 0.04 (claims 10 and 12-17)
-
S
≤ 0.0300 (claims 10, 14-15)
≤ 0.0200 (claims 12-13, 16-17)
-
Ni
1.50 - 8.00 (claims 10, 14-15)
1.50-2.50 (claims 12-13, 16-17)
0.5-1.5
Cr
18.00 - 28.00 (claims 10, 14-15)
18.00-21.50 (claims 12-13, 16-17)
19-22
Mo
0.01-5.00 (claims 10, 14-15)
0.01-0.60 (claims 12-13, 16-17)
≤ 0.5
Cu
0.05 - 1.50 (claims 10, 14-15)
0.50-1.50 (claims 12-13, 16-17)
≤ 1.00 (excluding 0)
N
0.080 - 0.320 (claims 10, 14-15)
0.150-0.200 (claims 12-13, 16-17)
0.2-0.3
One or more of (claims 14-15):
Al: 0.003-0.050
O: ≤ 0.007
Nb: 0.005-0.20
Ti: 0.005-0.20
Co: 0.005-0.25
V: 0.005-0.15
Sn: 0.005-0.20
Sb: 0.005-0.20
Ga: 0.001-0.050
Zr: 0.005-0.50
Ta: 0.005-0.100
B: 0.0002-0.005
-
Fe and impurities
Remainder
Balance (“and other inevitable impurities”)
Regarding the chemical composition of claims 10 and 12-17, elements with the limitation “or less”, such as C, Si, Mn, P, S, and O, are considered optional since the limitation “or less” includes a 0 mass% content.
WO’226 teaches a steel with a chemical composition (claim 1, [0046]-[0068]) and microstructure ([0001], [0069]-[0070], [0090]-[0091], both contain austenite and ferrite) overlapping with the claimed steel, as shown in List 1. Regarding the nickel content of claims 10 and 12-17, WO’226 teaches an upper limit of 1.5 wt% Ni, which overlaps with the lower limit of 1.5 mass% Ni of claims 10 and 12-17. Regarding the claimed P, S, and O contents, WO’226 does not explicitly teach the inclusion of P, S, and O and their content is therefore interpreted as a 0 wt% value, which reads on the claimed ranges shown in List 1 above. The Examiner notes that one of ordinary skill in the art understands mass% and wt% are used interchangeably in the metallurgical arts. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Regarding the limitation “in place of some Fe” of claims 14-17, the steel of WO’226 recites a remainder of Fe and other unavoidable impurities (claim 1) and therefore adding alloying elements to the steel of WO’226 would necessarily replace “some” of the remainder composed of iron and impurities. Therefore, WO’226 reads on the limitation “in place of some Fe” of claims 14-17.
WO’226 therefore reads on the chemical composition of claims 10 and 12-17.
Regarding the area ratio S<001>/S<111> of claim 10 and the surface waviness height of claim 11, WO’226 teaches the lean duplex stainless steel with improved bendability has a fine hardness difference of 120 Hv or less between the austenite phase and the ferrite phase ([0015], [0040], [0084], Inventive examples of Table 3 have ΔHv values above 50 Hv). WO’226 teaches that no cracks occur when the microhardness variation between the austenite and ferrite is 120 Hv or less ([0040]).
However, Kim does not explicitly disclose wherein, in a center part in the dual phase stainless steel sheet thickness of a cross section in a perpendicular-to-rolling direction which is a direction perpendicular to a rolling direction on a rolled surface of the dual phase stainless steel sheet and a direction parallel to a sheet thickness direction, an area ratio S<001>/S<111> which is a ratio of an area proportion S<001> of a texture of a ferrite with the <001> direction oriented in the perpendicular-to-rolling direction to an area proportion S<111> of a texture of a ferrite with the <111> direction oriented in the perpendicular-to-rolling direction is 0.90 to 1.10 of claim 10 and wherein the surface waviness height in the rolling direction is 0.3 μm or less of claim 11.
Since the steel sheet of WO’226 has a chemical composition (including Ni content), microstructure, and hardness difference overlapping with the instant invention, one of ordinary skill in the art would reasonably expect the steel sheet of WO’226 to necessarily possess the claimed area ratio S<001>/S<111> and claimed surface waviness height.
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, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). See MPEP § 2112.01 I. “Products of identical chemical composition can not have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112.01 II. Therefore, it is expected that the steel of the prior art possesses the properties as claimed in the instant claims since a) the claimed and prior art products are identical or substantially identical in composition (see compositional analysis above and in List 1), and b) the claimed and prior art products are identical or substantially identical in structure (see microstructure analysis above – both steels contain austenite and ferrite). Since the Office does not have a laboratory to test the reference alloy, it is applicant’s burden to show that the reference alloy does not possess the properties as claimed in the instant claims. See In re Best, 195 USPQ 430, 433 (CCPA 1977); In re Marosi, 218 USPQ 289, 292-293 (Fed. Cir. 1983); In re Fitzgerald et al., 205 USPQ 594 (CCPA 1980).
Given the overlap in chemical composition, microstructure, and hardness difference between the steel sheet of WO’226 and the instant invention, one of ordinary skill in the art would reasonably expect the steel sheet of WO’226 to necessarily possess the claimed area ratio S<001>/S<111> and claimed surface waviness height.
WO’226 therefore reads on the limitations wherein, in a center part in the dual phase stainless steel sheet thickness of a cross section in a perpendicular-to-rolling direction which is a direction perpendicular to a rolling direction on a rolled surface of the dual phase stainless steel sheet and a direction parallel to a sheet thickness direction, an area ratio S<001>/S<111> which is a ratio of an area proportion S<001> of a texture of a ferrite with the <001> direction oriented in the perpendicular-to-rolling direction to an area proportion S<111> of a texture of a ferrite with the <111> direction oriented in the perpendicular-to-rolling direction is 0.90 to 1.10 of claim 10 and wherein the surface waviness height in the rolling direction is 0.3 μm or less of claim 11.
As further evidence that one of ordinary skill in the art would reasonably expect the steel of WO’226 to necessarily possess the claimed area ratio and surface waviness, the instant specification recites when the difference ΔHv between the Vickers hardness of the austenite and the Vickers hardness of the ferrite is 50 HV or more, the area ratio S<001>/S<111> of the stainless steel sheet becomes 0.90 to 1.10 and as a result the waviness is reduced on the surface of the steel sheet ([0046]-[0047]). The instant specification further recites a Ni content is 1.50 to 8.00% to satisfy the difference between the Vickers hardness of the austenite and the Vickers hardness of the ferrite of the steel and the limitation “in a center part in a sheet thickness of a cross section in a perpendicular-to-rolling direction which is a direction perpendicular to a rolling direction on a rolled surface and a direction parallel to a sheet thickness direction, an area ratio S<001>/S<111> which is a ratio of an area proportion S<001> of a texture of a ferrite with the <001> direction oriented in the perpendicular-to-rolling direction to an area proportion S<111> of a texture of a ferrite with the <111> direction oriented in the perpendicular-to-rolling direction is 0.90 to 1.10” ([0020]).
WO’226 therefore reads on all limitations of claims 10-17.
Response to Arguments
Applicant’s arguments with respect to claims 10-17 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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 extension fee 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 date of this final action.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MAYELA ALDAZ whose telephone number is (571)270-0309. The examiner can normally be reached Monday -Thursday: 10 am - 7 pm and alternate Friday: 10 am - 6 pm.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Hendricks can be reached at (571) 272-1401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/M.A./Examiner, Art Unit 1733
/REBECCA JANSSEN/Primary Examiner, Art Unit 1733
Prosecution Insights