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 .
Claim Status
Applicants’ February 27, 2026 response to the December 01, 2025 Non-Final Rejection is acknowledged. Claims 1, 3 and 7-9 are pending, claim 1 is independent. Any rejections and/or objections, made in the previous Office Action, and not repeated below, are hereby withdrawn.
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 and 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over Shah (US 5782953 A) (of record), as evidenced by Ultrus Prospector (“ATI Steel ATI 409Cb”) and Gang Steel ("ASME SA240 ASTM 240 UNS S40945 Stainless Steel Sheet").
Regarding claims 1, 7 and 8, Shah teaches a sintered ferritic stainless steel article (body) where with a hardened outer surface layer of nitrogen in solid solution, dissolved in the outer surface layer (Abstract, Col. 2 Lns. 15-30), where the ferritic stainless steel includes 409 Cb (Col. 6 Lns. 19-20). Figures 4 and 5 are graphs of case hardness vs depth according to embodiment of the invention and shows higher hardness values at 200 microns from the surface of more than 250 Vickers Hardness for all examples, (Fig. 4, 5 and Col. 2 Lns. 57-61). 200 microns can therefore be considered the “hardened outer surface layer” due to solid solution hardening where nitrogen is dissolved in the outer surface layer (Col. 2 Lns. 28-30). One of ordinary skill in the art reasonably understands that nitrogen in solid solution (i.e. nitrogen dissolved in a crystalline structure) is interstitial (residing in gaps in a crystal lattice) nitrogen and that steel necessarily contains impurities.
Shah further teaches where with a hardened outer surface layer of nitrogen in solid solution, dissolved in the outer surface layer with at least 88% of theoretical density (Abstract, Col. 2 Lns. 15-30). Applicant teaches their relative density is measured by the Archimedes method ([0059] of the instant specification), which means relative density is equivalent to theoretical density (due to the density of water). Therefore, the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, (MPEP 2144.05 I)). Ultrus Prospector provides evidence that 409Cb alloy is synonymous with UNS S40945 (Pg. 2 [2]) and Gang Steel provides evidence that UNS S40945 (409Cb) stainless steel has a composition of C: ≤ 0.03%, N: ≤ 0.03%, Cr: 10.5-11.75%, Si: ≤ 1.0%, and Nb: 0.05-0.35 (Pg. 7; i.e. including values of C/Nb of C: 0.03 and Cb of 0.05 that calculate to 0.6).
Excepting N and Cr the proportions disclosed and evidenced by the prior art overlap applicants claimed proportions and therefore establish a prima facie case of obviousness, where 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 the prior art, including those proportions, which satisfy the presently claimed requirements. As of the writing of this Office Action, no objective evidence of criticality to the claimed ranges has been presented.
Regarding N and Cr a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close (Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985) (MPEP 2144.05 I)). There is no evidence in the prior art that a difference in properties is expected between 0.03% and 0.05% N, further the applicants’ own specification allows for values approaching 0% N with no difference in properties shown ([0029] of applicants’ specification).
Regarding claim 3, Shah as evidenced by Ultrus Prospector and Gang Steel teaches each limitation of claim 1, as discussed above. Shah does not specifically teach “a potential at which a current density measured according to method B among methods of pitting potential measurement for stainless steel defined in JIS G 0577:2014 is 100 microA/cm2 is 700mV or more.
However, when the structure recited in the reference is substantially identical to that of the claims, the claimed properties are presumed to be inherent, i.e. 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 obviousness has been established (MPEP 2112.01 I). In this instance, the prior art of Shah teaches substantially identical product to the claimed structure and composition (claims 1 and 4 rejections), and one of ordinary skill in the art before the effective filing date of the invention would have expected the material of Shah to have substantially identical properties to those of applicant, and possess the claimed potential property. As the PTO has a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not (MPEP 2112.01 I).
Regarding claim 9, Shah as evidenced by Ultrus Prospector and Gang Steel teaches each limitation of claim 1, as discussed above and teaches the ferritic stainless steel includes 409 Cb (Col. 6 Lns. 19-20). Ultrus Prospector provides evidence that 409Cb alloy is synonymous with UNS S40945 (Pg. 2 [2]) and Gang Steel provides evidence that UNS S40945 (409Cb) stainless steel includes ≤ 0.040% P, ≤ 0.020% S and ≤ 0.03% N (Pg. 7). One of ordinary skill in the art reasonably understands P, S and N to be common impurities in stainless steel. Where these are limited to ≤0.09% in total, it is understood that the total amount of impurities in the steel would be overlapping with that claimed. Oxygen is not explicitly listed and is understood to be absent, or at minimum overlapping applicants claimed range (which includes 0%).
The proportions disclosed and evidenced by the prior art overlap applicants claimed proportions and therefore establish a prima facie case of obviousness, where 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 the prior art, including those proportions, which satisfy the presently claimed requirements. As of the writing of this Office Action, no objective evidence of criticality to the claimed ranges has been presented.
Response to Arguments
Applicant's arguments filed February 27, 2026 have been fully considered but they are not persuasive. Examiner notes that although applicant further alleges criticality of the claimed subject matter; however, no specific evidence is referenced or proffered, and as such there is no persuasive argument that any alleged difference in results are unexpected and unobvious and of both statistical and practical significance. (MPEP 716.02 (b)). To establish the unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed ranges to show the criticality of the claimed range (MPEP 716.02(d),II). This data has not been provided, nor compared; therefore, this is not persuasive. General references to “it is possible to achieve…” from the specification absent specific data is not evidence of unexpected and unobvious results of statistical and practical significance. Therefore, this argument is not persuasive.
For these reasons, and for those reasons as advanced in the rejections above, the present claims are not found to distinguish over the prior art and this action is made FINAL.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KATHERINE CHRISTY whose telephone number is (303)297-4363. The examiner can normally be reached Monday-Thursday, 7am-4pm MT.
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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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/KATHERINE A CHRISTY/Primary Examiner, Art Unit 1784