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
An amendment, filed 11/7/2025, is acknowledged. Claims 1 and 3 are amended; claims 2 and 4 are canceled. Claims 1 and 3 are currently pending.
The rejection of claims 1-4 under 35 U.S.C. 112(b) is withdrawn in view of Applicant’s amendments to the claims.
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.
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.
Claim(s) 1 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Kochi (US 2019/0010565) in view of Suehiro (US 5045124)(previously cited) and (Unno (US 2018/0237882)(previously cited) and Takagi (US 2019/0112694)(previously cited) or in the alternative to Takagai, Kochi et al. (WO2020067444A1)(cited on the IDS, dated 9/26/2025)(machine translation provided)(hereafter, “Kochi ’444”).
With respect to Claim 1, Kochi teaches a method of manufacturing an austenitic stainless steel, the method comprising hot working and cold working a steel material, for example, hot rolling and cold rolling a planar steel material (i.e. steel strip), wherein the steel material may have a composition, in mass%, as follows (para. 33-54, 90, 99):
Claim 1
Kochi
Ni
20.0-30.0
25-45
Cr
15.0-18.0
10-30
Mo
1.0-2.0
0-4
Al
3.5-5.0
2.5-4.5
Nb + Ta
1.0-2.0 total
Nb: 0.2-3.5
Ti + V
0-0.3 total
Ti: 0-0.2
Si
0-1.0
0.01-2.0
Mn
0-2.0
0-2.0
Zr
0.01-0.3
0-0.1
C
0.005-0.045
0.03-0.25
B
0.001-0.03
0-0.01
Other
Optionally, 0.01-0.5 total of one or more of Y, La, Ce, and Hf
0-0.1 REM (thus, including Y, La, and Ce)
Fe
Remainder with unavoidable impurities
Balance with impurities
Compositional ranges including zero (e.g. claimed ranges of Ti, V, Si, and Mn are interpreted as optional elements and where ranges are stated as a group/total (e.g. Nb + Ta) only one of the elements is interpreted as required so long as the range is met. With respect to end points reciting phrases such as “more than” or less than,” such ranges include values so close to the endpoint as to be indistinguishable from the endpoint value and therefore, prior art ranges teaching such an endpoint value will be treated as meeting/overlapping the claimed range. See also MPEP 2144. It is further noted that the recited phrase “as necessary, at least one of Y, La, Ce and Hf” is interpreted as reciting the optional inclusion of one or more of such elements.
Thus, Kochi teaches a stainless steel having a composition overlapping each of the instantly required ranges. It would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. Overlapping ranges, in particular, where the ranges of a claimed composition overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
As discussed above, Kochi teaches performing a hot rolling step on the stainless steel material, followed by cold rolling, then teaches performing a solution heat treatment step, comprising heating the cold worked/rolled steel material to a temperature of 1100-1250 C for 1 to 60 minutes, overlapping the claimed temperature and maintaining times. (para. 91-94). Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Kochi is silent as to the atmosphere in which the solution heat treatment is carried out and a rate of cooling after the solution treatment.
Unno teaches a method of making an austenitic stainless steel, the method comprising heating the steel material in an argon or other rare gas atmosphere, the atmosphere comprising 0.1 mass% or less nitrogen (interpreted to overlap the claimed “non-oxidizing atmosphere free of nitrogen”) so as to prevent nitriding on the surface of the stainless steel material. (para. 36, 89).
It would have been obvious to one of ordinary skill in the art to perform the solution heat treatment of Kochi in an argon atmosphere free of nitrogen, as taught by Unno, in order to prevent nitriding on the surface of the stainless steel material. Overlapping ranges, in particular, where the ranges of a claim overlap with the ranges disclosed in the prior art, have been held sufficient to establish a prima facie case of obviousness. MPEP § 2144.05.
Suehiro teaches a method of making an austenitic stainless steel, the method comprising cold rolling a steel strip, heating to a temperature of 1050° C or higher, then cooling at a rate of at least 10°C/sec. (col. 2, ln. 3-7, 30-34).
It would have been obvious to one of ordinary skill in the art to modify the method of Kochi in view of Unno, to cool the solution heat treated steel at a rate of 10°C/sec, as taught by Suehiro, in order to maintain the structure formed during the heat treatment, for example, to maintain or substantially maintain elements in solid solution.
Finally, Kochi teaches examples wherein the austenitic stainless steel is hot rolled and cold rolled in a planar form with a thickness of 1.5 mm, thus constituting an austenitic stainless steel strip meeting the claimed thickness. (para. 99). Kochi teaches, in this example, wherein an initial material has a diameter of 120 mm. (Id.). Additionally, it is noted that a mere change in form has been held to be prima facie obvious. See MPEP 2144.05; Smith v. Nichols, 88 U.S. 112, 118-19 (1874) (a change in form, proportions, or degree "will not sustain a patent"); In re Williams, 36 F.2d 436, 438 (CCPA 1929) ("It is a settled principle of law that a mere carrying forward of an original patented conception involving only change of form, proportions, or degree, or the substitution of equivalents doing the same thing as the original invention, by substantially the same means, is not such an invention as will sustain a patent, even though the changes of the kind may produce better results than prior inventions.").
As Kochi teaches forming a steel strip with a thickness falling within the claimed range and envisions steel materials having at least an initial dimension of 120 mm, it would have been obvious to one of ordinary skill in the art to form a steel strip, using the method of Kochi in view of Unno and Suehiro, to form a steel strip having a sheet width of 120 mm or more and a sheet thickness of 1.5 mm. In other words, it would have been obvious to one of ordinary skill in the art to roll a steel material to a desired width based on desired applications of the sheet and it would have been obvious to one of ordinary skill in the art to form a sheet with a width of 120 mm or more, as Kochi envisions hot and cold working the stainless steel material on this scale.
Finally, Kochi is silent as to the resulting grain size of the austenitic stainless steel.
Takagi teaches an austenitic stainless steel material wherein the steel material has an ASTM grain size number of 6.0 or more (45 microns or more). Para. 15, 24). As the reference teaches an austenitic stainless steel with the stated grain size, it is interpreted as teaching an average austenite grain size overlapping the instantly claimed range. Takagi teaches that by controlling the grain size of the steel material to a size of 45 microns or more, a steel material having improved strength is obtained. (para. 59).
Kochi ’444 teaches an austenitic stainless steel material with compositional ranges of at least C, Si, Mn, Cr, Ni, and Al overlapping the instantly claimed ranges and wherein the steel material has an average grain size of 60-130 microns, preferably 73-110 microns. (pgs. 1, 14-15 of translation). Kochi ’444 teaches that this grain size results in excellent creep strength. (pgs. 14-15 of translation).
It would have been obvious to one of ordinary skill in the art to modify the method of Koch in view of Unno and Suehiro to control the grain size of the austenitic steel material to an average size of 45 microns or more, as taught by Takagi or in the alternative, an average grain size of 60-130 microns, preferably 73-110 microns, as taught by Kochi ’444, in order to obtain a steel material having improved strength and/or creep strength. Additionally, it would have been obvious to one of ordinary skill in the art to select from the portion of the overlapping ranges. MPEP § 2144.05. In other words, one of ordinary skill in the art would recognize the ability to control the grain size of a steel material in order to obtain known results, here, a known average grain size corresponding to improved strength/creep strength.
Allowable Subject Matter
Claim 3 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: prior art of record fails to teach a step of polishing removing an oxide layer and a nitride layer formed during the hot rolling step of claim 1, wherein the polishing step takes place between the hot rolling step and the cold rolling step or during the cold rolling step.
Response to Arguments
Applicant's arguments filed 11/7/2025 with respect to the rejection of Claim 1 under 35 U.S.C. 103 have been fully considered but they are not persuasive.
Applicant argues that prior art Takagi teaches an austenitic steel that is not a high-aluminum steel and therefore, the average grain size could not necessarily be obtained by the combination detailed in the 103 rejection. (Remarks, pg. 9). Applicant also argues that the grain size feature “achieves an unexpected effect, as sufficient creep strength, tensile ductility, and impact toughness are obtained.” (Remarks, p. 9). These arguments have been fully considered but are not found persuasive.
One of ordinary skill in the art would recognize the ability to control the grain size of a steel material in order to obtain known results, here, a known average grain size corresponding to improved strength/creep strength as detailed in the rejection above. The ability to control the grain strength of a rolled steel material requires no more than one of ordinary skill in the art, and one would be motivated to select an average grain size of 45 microns or more in order to improve the strength of the steel material as taught by Takagi. This improvement in strength would be expected to a broader range of austenitic stainless steel compositions, not only those having the aluminum content of the instant claims.
In fact, the instant specification appears to admit that grain size of austenitic steels is a known value correlating with creep strength. Paragraph 16 of the PG Pub. states “The crystal grain size is a structural factor that greatly affects the creep strength, and it is necessary to increase the crystal grain size in order to obtain high creep strength, and thus it is thought that the final heat treatment temperature of the austenitic stainless steel disclosed in Non-Patent Literature 1 to 3 needs to be 1,200° C. or higher.”
Applicant fails to provide sufficient evidence to demonstrate unexpected results with respect to average grain size and creep strength, tensile ductility, or impact toughness. “’Objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support.’ In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range.” MPEP 716.02(d). To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). Here, comparative examples 7 and 8 include average austenite grain size below the claimed range, but no example exists above the range and prior art Takagi teaches a range of 45 microns or more, exceeding the minimum claimed value of 30 microns.
Applicant’s arguments with respect to the rejection of claim 3 under 35 U.S.C. 103 have been fully considered and are persuasive in view of Applicant’s amendment to the claim. Specifically, the prior art of record fails to teach a step of polishing removing an oxide layer and a nitride layer formed during the hot rolling step of claim 1, wherein the polishing step takes place between the hot rolling step and the cold rolling step or during the cold rolling step. The rejection has been withdrawn.
Finally, in view of Applicant’s newly filed IDS document and/or amendments to the claims, an alternative new grounds of rejection in view of Kochi ’444 (WO2020067444A1) is made, as detailed above.
Conclusion
Applicant's amendment and/or Applicant's submission of an information disclosure statement under 37 CFR 1.97(c) with the timing fee set forth in 37 CFR 1.17(p) on 9/26/2025 prompted 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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/JOHN A HEVEY/ Primary Examiner, Art Unit 1735