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 .
Priority
Applicant’s pending application, 18/355,913 filed July 20, 2023, claims priority to US Provisional Application 63/391,512 filed July 22, 2022.
Claim Status
This Office Action is in response to Applicant’s Remarks and Claim Amendments filed April 20, 2026. Applicant’s affirmation of the election of Group I and Species I-Wrought, claims 1 and 4-9, is acknowledged (Remarks p. 8 para. 2).
Claims Filing Date
April 20, 2026
New
18, 19
Cancelled
2, 11
Pending
1, 3-10, 12-19
Withdrawn
3, 10, 12-17, 19
Under Examination
1, 4-9, 18
The applicant argues support for the new claims in Table 3 (p. 8 para. 1).
The status identifier of claim 3 is “Original”. However, in the 1/20/2026 Non-Final Rejection restriction Requirement and Election there was a species restriction between Species I-Cast and Species I-Wrought (p. 5) with applicant orally electing Species I-Wrought (p. 6). Therefore, claim 3 is withdrawn from consideration and the status identifier should reflect this. 37 C.F.R. 1.121.
Newly submitted claim 19 is directed to an invention that is independent or distinct from the invention originally claimed for the following reasons: new claim 19 depends from withdrawn claim 15. In the 1/20/2026 Non-Final Rejection Restriction Requirement and Election, the Group I, claims 1-9, duplex stainless steel alloy, claims were elected for prosecution (pp. 2-6).
Since applicant has received an action on the merits for the originally presented invention, this invention has been constructively elected by original presentation for prosecution on the merits. Accordingly, claim 19 is withdrawn from consideration as being directed to a non-elected invention. See 37 CFR 1.142(b) and MPEP § 821.03.
To preserve a right to petition, the reply to this action must distinctly and specifically point out supposed errors in the restriction requirement. Otherwise, the election shall be treated as a final election without traverse. Traversal must be timely. Failure to timely traverse the requirement will result in the loss of right to petition under 37 CFR 1.144. If claims are subsequently added, applicant must indicate which of the subsequently added claims are readable upon the elected invention.
Should applicant traverse on the ground that the inventions are not patentably distinct, applicant should submit evidence or identify such evidence now of record showing the inventions to be obvious variants or clearly admit on the record that this is the case. In either instance, if the examiner finds one of the inventions unpatentable over the prior art, the evidence or admission may be used in a rejection under 35 U.S.C. 103 or pre-AIA 35 U.S.C. 103(a) of the other invention.
Withdrawn Abstract Objection
The following objection is withdrawn due to abstract amendment:
Legal phraseology “comprising” in line 2 and “consisting essentially of” line 4.
Withdrawn Specification Objections
The following objection is withdrawn due to persuasive argument:
2:21, 3:18, 4:11, 27 “40 wt% - 60 wt% ferrite and 60 wt% - 40 wt% austenite”.
The applicant persuasively argues the literature describes ferrite and austenite content as wt% (p. 8 para. 5) and that for ferrite and austenite vol% and wt% are substantially the same (p. 9 para. 2).
Withdrawn Claim Objection
The following objection is withdrawn due to persuasive argument:
Claim 1 lines 13-14 “40 wt% - 60 wt% ferrite and 60 wt% - 40 wt% austenite”.
The applicant persuasively argues the literature describes ferrite and austenite content as wt% (p. 8 para. 5) and that for ferrite and austenite vol% and wt% are substantially the same (p. 9 para. 2).
Response to Remarks filed April 20, 2026
Abe in view of Yamagishi
Applicant's arguments filed April 20, 2026 with respect to Abe in view of Yamagishi have been fully considered but they are not persuasive.
The applicant argues Abe teaches against higher Cu content disclosing an upper limit of 1.5% or less to improve corrosion resistance, preferably a higher limit of 1.0% (p. 10 para. 4).
The prior art’s disclosure of more than one alternative does not constitute a teaching away because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed. MPEP 2123(II).
Abe discloses Cu to improve corrosion resistance in a range of 1.5% or less ([0046]). However, Abe does not criticize, discredit, or otherwise discourage including up to 3% Cu, which advantageously improves corrosion resistance in a non-oxidizing environment, particularly pitting corrosion resistance (Yamagishi [0013]).
The applicant argues a single Cu element from Yamagishi cannot be combined with Abe because as a whole Yamagishi has lower Mo and higher Cr (p. 10 para. 5).
Yamagishi does not disclose that in order to achieve the improved corrosion resistance of the 0.1 to 3% Cu the disclosed Mo content and Cr content are also necessary. Rather, both Abe and Yamagishi disclose duplex stainless steel (Abe [0025], [0066]; Yamagishi [0001]) including Cu to improve corrosion resistance (Abe [0046]; Yamagishi [0013]), such that the alleged Mo and Cr differences do not change the effect of the Cu.
The applicant argues Abe does not target the fabrication of duplex compositions because only two samples, A15 and B3, of twenty-two are duplex alloys, but neither has the claimed Mo composition, for A5 with the Mo content, the structure is super austenitic, but the Ni and Cr are outside the claimed respective ranges, and none of the examples have the claimed Nieq and Creq values (para. spanning pp. 10-11), where the Nieq and Creq in Abe are not sufficient for teaching formation of a duplex alloy with the claimed composition (p. 11 para. 2).
A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. MPEP 2123(I). Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. MPEP 2123(II).
Abe discloses “two-phase” (duplex) stainless steel ([0025], [0066]) with an overlapping composition, including Nieq and Creq values ([0021]-[0022], [0035]-[0061]) such that a prima facie case of obviousness exists. MPEP 2144.05(I).
For the above cited reasons, the rejection of Abe in view of Yamagishi is maintained.
Adachi in view of Zhang and Yamagishi
Applicant's arguments filed April 20, 2026 with respect to Adachi in view of Zhang and Yamagishi have been fully considered but they are not persuasive.
The applicant argues Adachi does not include Mo and Co (p. 11 para. 4), and the rejection relies on Zhang for the addition of Mo and Yamagishi for the addition of Co (p. 11 para. 5), where adding Mo as disclosed by Zhang to Adachi results in a ferrite alloy, not a duplex alloy (p. 11 para. 6, pp. 12-13).
Objective evidence must be factually supported by an appropriate affidavit or declaration. MPEP 716.01(c)(I). Arguments presented by the applicant cannot take the place of evidence in the record. MPEP 716.01(c)(II). Applicants have the burden of explaining proffered data. MPEP 716.02(b)(II).
The graphs of volume fraction of all phases versus temperature for the Adachi “standard” chemistry and the Adachi “Mo modified” with 7.3 wt% Mo have not been explained to support how adding Mo as disclosed by Zhang to Adachi necessarily results in a ferrite alloy. For example, in the “Mo modified” graph there appears to be temperatures at which approximately equal amounts of ferrite and austenite exist between the temperature range of 1500 to 1600°F. Furthermore, the data is only presented for what applicant calls Adachi “standard” chemistry. However, the objective evidence of nonobviousness must be commensurate in scope with the that which the evidence is offered to support. MPEP 716.02(d).
The applicant argues the impact of Mo according to Zhang is different from Adachi and the claimed alloy, such that one of ordinary skill in the art would not be motivated to include Mo as disclosed by Zhang without undue experimentation by Adachi (p. 14 para. 1).
In response to applicant's argument that the impact of Mo according to Zhang is different from the claimed alloy, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
The applicant argues only alloys F, J, and L of the 12 composition of Table 1 in Adachi fulfill Nieq and Creq, but they have higher Cr, no Mo or Co, and either more or less Ni, such that there are significant compositional differences (p. 14 para. 2).
A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. MPEP 2123(I). Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. MPEP 2123(II).
Adachi in view of Zhang and Yamagishi discloses a duplex (austenite and ferrite two-phase) stainless steel (Adachi [0001], [0021]-[0022]) with a composition (Adachi [0022], [0025]-[0026], [0032]-[0039]; Zhang STN Abstract and Composition; Yamagishi [0012]), microstructure (Adachi [0022], [0041]), nickel equivalent (Adachi [0022], [0032], [0034], [0036]-[0037]), and chromium equivalent (Adachi [0033], [0035], [0037]-[0038; Zhang STN Abstract) that overlap with that claimed such that a prima facie case of obviousness exist. MPEP 2144.05(I).
For the above cited reasons the rejection of Adachi in view of Zhang and Yamagishi is maintained.
Double Patenting
The applicant argues the Terminal Disclaimer renders the double patenting rejection moot (para. spanning pp. 14-15).
The Terminal Disclaimer filed April 20, 2026 listing US application number 19/365,534 was approved on April 29, 2026.
Claim Interpretation
Claim 1 lines 14-22 “…the nickel equivalent and the chromium equivalent are defined as one of (i)…(ii)…” are interpreted as referring to two different methods to calculate nickel equivalent and chromium equivalent. Pages 7-8 of applicant’s specification recite a nickel equivalent and chromium equivalent according to the Schaeffler diagram and, alternatively, according to Long and DeLong.
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 and 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Abe (JP 2016-204714 machine translation) in view of Yamagishi (JP H08-013094 machine translation).
Regarding claim 1, Abe discloses a duplex (two-phase) stainless steel ([0025], [0066]) with an overlapping composition ([0021]-[0022], [0035]-[0061]), wherein the stainless steel alloy comprises 40 wt% - 60 wt% ferrite and 60 wt% - 40 wt% austenite (two-phase, which reads on having approximately equal proportions of ferrite and austenite) ([0025], [0066]) and has an overlapping nickel equivalent ([0036], [0038], [0042], [0043]) and chromium equivalent ([0037], [0041], [0045], [0047]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Feature
Claim 1
Abe Disclosure
Abe Citation
Cr
12 to 17
10.5 to 30
[0041]
Mo
7.25 to 11
0.1 to 8
[0045]
Ni
0.75 to 5
0.5 to 9
[0042]
Mn
2.5 to 8
0.02 to 4.0
[0038]
Cu
1.75 to 3.5
0.05 to 1.5
[0046]
N
0.1 to 0.3
0.001 to 0.3
[0043]
C
0.075 to 0.2
0.10 or less
[0036]
Co
0.01 to 3
-
-
Si
Less than 1.5
0.02 to 4.0
[0037]
W
Less than 1.5
0.01 to 1.0
[0050]
Fe
Balance
Remainder
[0021]
Nb
-
1.0 or less
[0047]
Ferrite
40 to 60
About 50
[0025], [0066]
Austenite
60 to 40
About 50
[0025], [0066]
One of the following:
(i)Nieq
Creq
>7 to <20
>21 to <38
0.7 to 14
10.6 to 44.5
-
(ii)Nieq
Creq
>10 to <18
>21 to <27
0.7 to 23
10.6 to 44.5
-
Abe discloses 0.05 to 1.5% Cu to improve corrosion resistance ([0046]).
Abe is silent to 1.75 to 3.5% Cu.
Yamagishi discloses a duplex stainless steel ([0001]) with 0.1 to 3% Cu ([0013]).
It would have been obvious to one of ordinary skill in the art in the two-phase stainless steel of Abe to include up to 3% Cu to improve corrosion resistance in a non-oxidizing environment, particularly pitting corrosion resistance (Yamagishi [0013]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Abe is silent to Co.
Yamagishi discloses a duplex stainless steel ([0001]) with 0.01 to 0.27% Co ([0012]).
It would have been obvious to one of ordinary skill in the art in the two-phase stainless steel of Abe to include 0.01 to 0.27% Co to improve crevice corrosion resistance and elongation by concentrating in the austenite phase (Yamagishi [0012]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 4, Abe discloses the stainless steel alloy comprises wrought steel (fastening parts of automobile exhaust systems manufactured from cold-rolled and annealed steel sheets) ([0001], [0025], [0031], [0066], [0078]).
Regarding claim 5, a yield strength of at least 70 ksi has been considered and determined to recite a property that naturally flows from the claimed duplex stainless steel. The prior art discloses an overlapping composition (Abe [0021]-[0022], [0035]-[0061]; Yamagishi [0012], [0013]) and microstructure (Abe [0025], [0066]), such that the claimed property of a yield strength of at least 70 ksi naturally flows from the disclosure of the prior art.
Regarding claim 6, an ultimate tensile strength of at least 115 ksi has been considered and determined to recite a property that naturally flows from the claimed duplex stainless steel. The prior art discloses an overlapping composition (Abe [0021]-[0022], [0035]-[0061]; Yamagishi [0012], [0013]) and microstructure (Abe [0025], [0066]), such that the claimed property of an ultimate tensile strength of at least 115 ksi naturally flows from the disclosure of the prior art.
Regarding claim 7, an elongation >30% has been considered and determined to recite a property that naturally flows from the claimed duplex stainless steel. The prior art discloses an overlapping composition (Abe [0021]-[0022], [0035]-[0061]; Yamagishi [0012], [0013]) and microstructure (Abe [0025], [0066]), such that the claimed property of an elongation >30% naturally flows from the disclosure of the prior art.
Regarding claim 8, a reduction of area >50% has been considered and determined to recite a property that naturally flows from the claimed duplex stainless steel. The prior art discloses an overlapping composition (Abe [0021]-[0022], [0035]-[0061]; Yamagishi [0012], [0013]) and microstructure (Abe [0025], [0066]), such that the claimed property of a reduction of area >50% naturally flows from the disclosure of the prior art.
Regarding claim 9, applicant’s specification discloses at 13:1-3 “pitting resistance equivalent number (PREN)…calculated as %Cr + 3.3(%Mo) + 16(%N) – 1.6(%Mn)”. Abe discloses N is useful for pitting corrosion resistance ([0043]) and a PREN of 4.4 to 61.1 (Abe [0038], [0041], [0043], [0045]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Claims 1 and 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Adachi (JP 2016-60936 machine translation) in view of Zhang (Zhang et al. Effect of Mo on microstructure and pitting resistance of duplex-phase cast stainless steel, Dalian Ligong Daxue Xuebao (1994), 34(2), 150-155. STN.) and Yamagishi (JP H08-013094 machine translation).
Regarding claim 1, Adachi discloses a duplex (austenite and ferrite two-phase) stainless steel ([0001], [0021]-[0022]) with a composition ([0022], [0025]-[0025], [0032]-[0039]), microstructure ([0022], [0041]), and nickel equivalent ([0022], [0032], [0034], [0036]-[0037]) that overlap with that claimed as presented in the following table. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Adachi is silent to 7.25 to 11 wt% Mo.
Zhang discloses duplex stainless steel with 2.6 to 7.4 wt% Mo (STN Abstract and Composition).
It would have been obvious to one of ordinary skill in the art in the duplex stainless steel of Adachi to include 2.6 to 7.4 wt% Mo to improve the pitting resistance (Zhang STN Abstract). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Adachi in view of Zhang discloses a composition with a Creq that overlaps with that claimed (Adachi [0033], [0035], [0037]-[0038]; Zhang STN composition). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Feature
Claim 1
Adachi Disclosure
Adachi Disclosure- Mo Modified
Adachi Citation
Cr
12 to 17 wt%
10.0 to 28.0
10.0 to 28.0
[0035]
Mo
7.25 to 11 wt%
-
2.6 to 7.4
-
Ni
0.75 to 5 wt%
2.0 or less
2.0 or less
[0037]
Mn
2.5 to 8 wt%
0.1 to 6.0
0.1 to 6.0
[0034]
Cu
1.75 to 3.5 wt%
2.0 or less
2.0 or less
[0037]
N
0.1 to 0.3 wt%
0.17 or less
0.17 or less
[0036]
C
0.075 to 0.2 wt%
0.1 to 0.4
0.1 to 0.4
[0032]
Co
0.01 to 3 wt%
-
-
-
Si
Less than 1.5 wt%
2.0 or less
2.0 or less
[0033]
W
Less than 1.5 wt%
-
-
-
Fe
Balance
Balance
Balance
[0039]
Nb
-
0.5 or less
0.5 or less
[0038]
Ferrite
40 to 60 %
Remainder
Remainder
[0041]
Austenite
60 to 40 %
10 to 90%
10 to 90%
[0041]
One of the following:
(i)Nieq
Creq
>7 to <20
>21 to <38
3.0 to 17
-
3.0 to 17
12.6 to 38.7
-
(ii)Nieq
Creq
>10 to <18
>21 to <27
3.0 to 22
-
3.0 to 22.1
12.6 to 38.7
-
Adachi is silent to Co.
Yamagishi discloses a duplex stainless steel ([0001]) with 0.01 to 0.27% Co ([0012]).
It would have been obvious to one of ordinary skill in the art in the two-phase stainless steel of Adachi to include 0.01 to 0.27% Co to improve crevice corrosion resistance and elongation by concentrating in the austenite phase (Yamagishi [0012]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 4, Adachi discloses the stainless steel alloy comprises wrought steel (springs manufactured by hot and cold working and heat treatment) ([0001], [0013]-[0016], [0026]-[0029], [0049]-[0058]).
Regarding claim 5, Adachi discloses a yield strength of at least 70 ksi (450 MPa or more, 65 ksi or more) ([0014]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 6, Adachi discloses an ultimate tensile strength of at least 115 ksi (1 GPa or more, 145 ksi or more) ([0014]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 7, Adachi discloses an elongation >30% (25% or more) ([0015]). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Regarding claim 8, a reduction of area >50% has been considered and determined to recite a property that naturally flows from the claimed duplex stainless steel. The prior art discloses an overlapping composition (Adachi [0022], [0025]-[0025], [0032]-[0039]; Zhang STN Abstract and Composition; Yamagishi [0012]) and microstructure (Adachi [0022], [0041]), such that the claimed property of a reduction of area >50% naturally flows from the disclosure of the prior art.
Regarding claim 9, applicant’s specification discloses at 13:1-3 “pitting resistance equivalent number (PREN)…calculated as %Cr + 3.3(%Mo) + 16(%N) – 1.6(%Mn)”. Adachi in view of Zhang discloses an PREN of 9.0 to 55 (Adachi [0034]-[0036]; Zhang STN composition). In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. MPEP 2144.05(I).
Allowable Subject Matter
Claim 18 is allowed.
The following is an examiner’s statement of reasons for allowance:
The above cited prior art (Abe in view of Yamagishi; Adachi in view of Zhang and Yamagishi) disclose a duplex stainless steel comprising 0.1 to 8 % Mo (Abe [0025], [0045], [0066]) or 2.6 to 7.4 wt% Mo (Adachi [0001], [0021]-[0022]; Zhang STN Abstract and Composition). However, neither of these disclosed Mo contents read on or overlap with the new claim 18 recitation of 8.84 wt% to 11 wt% Mo.
Further, prior art, such as Muto (JP H04-198456 machine translation), discloses a ferritic-austenitic duplex stainless steel (p. 1) with 9% or less Mo (p. 2). Some of the other elements disclosed by Muto, such as Si, Ni, and N (pp. 2-3) also overlap with that claimed. However, other elements disclosed by Muto, such as C, Mn, and Cr do not overlap with that claimed. Furthermore, Muto is silent to the presence of Cu and Co.
Therefore, the prior art either alone or in combination does not teach or suggest a duplex stainless steel alloy comprising 8.84 wt% to 11 wt% Mo in combination with the other compositional elements recited in claim 1 and the required combination of nickel equivalent and chromium equivalent.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
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.
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANI HILL whose telephone number is (571)272-2523. The examiner can normally be reached Monday-Friday 7am-12pm.
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/STEPHANI HILL/Examiner, Art Unit 1735
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