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 .
Status of Claims
Claims 4-5 are withdrawn. Claims 6-8 are new. Claims 1-3 and 6-8 are examined herein.
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.
Claims 1-3, 6 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Song (US 2023/0107193), and further in view of JP’452 (JP2008-163452), as evidenced by Hardness Conversion Table.
Regarding claims 1, 3 and 6, Song discloses (Abstract; [0029] to [0053]) a martensitic stainless steel with a composition that meets the recited amount of C, Si, Mn, Cu, Cr, Ni and N in claim 1.
Element
Claim 1
(mass %)
Song
(mass %)
Overlap
(mass %)
C
0.03-1.2
0.14-0.21
0.14-0.21
Si
0-1
0.1-0.6
0.1-0.6
Mn
0-1.5
0.4-1.2
0.4-1.2
P
≤0.06
---
---
S
≤0.25
---
---
Cu
≤0.5
0
0
Cr
8-22
14-17
14-17
Ni
0-1
0
0
N
≤0.4
0.05-0.11
0.05-0.11
Fe + Impurities
Balance
Balance
Balance
Song discloses an example containing: 0.162 mass % C, 0.31 mass% Si, 0.98 mass% Mn, 0 mass % Cu, 14.97 mass % Cr, 0 mass % Ni, 0.01 mass % Mo, and 0.095 mass % N (Abstract; Table 1, Steel Type F), which meets the recited amount of C, Si, Mn, Cu, Cr, Ni, Mo and N in claim 1. Song discloses that the steel contains unavoidable impurities ([0045]). Since P and S are well-known unavoidable impurities in steel, the steel disclosed by Song meets the transitional phrase “consisting of” as recited in claim 1.
Song is silent on the amount of P and S. JP’452 teaches a martensitic stainless steel having major composition overlapping the composition disclosed by Song (See Abstract). JP’452 discloses that controlling the amount of P to 0.035 mass% or less is essential to make a steel having high toughness and controlling the amount of S to 0.015 mass% or less is essential to make a steel having good hot workability (Page 5, 3rd and 4th paragraphs). Thus, it would be obvious to one of ordinary skill in the art to control the amount of P to 0.035 mass% or less and the amount of S to 0.015 mass% or less as taught by JP’452 in the steel of Song in order to make a steel having high toughness and good hot workability as disclosed by JP’452.
Song discloses that the steel has martensite structure ([0077]; [0078]), which meets the phase limitation recited in claim 1.
Song further discloses that the steel has hardness of 47-51 HRC ([0083]), which converts to a tensile strength of 1580-1820 according to Hardness Conversion Table and overlaps the recited tensile strength in claims 1 and 6. 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. Thus, the recited tensile strength is a prima facie case of obviousness over Song.
Song is silent on a content of the precipitate, crystal grain size number of prior austenite grains, and DH2(0.7)/Dair as recited in claim 1 and the morphology of the precipitates as recited in claim 3. However, these structure and property limitations depend on the steel composition and a method of making the steel.
Song discloses a method of making the steel comprising heating the steel at 840 ºC for 10 hours, lower the temperature to 580 ºC at a cooling rate of 15 ºC/h, then heating the steel at 1050 ºC for 1-30 minutes followed by quenching, and finally tempering at 400-600 ºC for 30 minutes to 2 hours ([0051] to [0094]), which meets the processing conditions disclosed in Paragraph [0051] to [0067] of instant Specification.
In view of the fact that Song in view of JP’452 teaches a martensitic steel having composition that meets the recited composition in claim 1 and a method of making the steel that meets the processing conditions disclosed in instant Specification, one of ordinary skill in the art would expect that the steel disclosed by Song in view of JP’452 to meet the content of a precipitate, the crystal grain size number of prior austenite grains, and the DH2(0.7)/Dair as recited in claim 1 and the precipitate contains a branched carbonitride as recited in claim 3. “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.
The preamble “for a hydrogen gas environment” recited in claim 1 is intended use. When the preamble only states a purpose or intended use for the invention, the preamble is not a claim limitation. See MPEP2111.02 II. Thus, claims 1 and 3 are obvious over Song in view of JP’452.
Regarding claim 2, Song does not teach that the steel contains at least one element selected from the group consisting of V, Nb and Pb. JP’452 teaches a martensitic stainless steel having major composition overlapping the composition disclosed by Song (See Abstract). JP’452 discloses that 0.005-0.05 mass% Nb is beneficial for improving corrosion resistance (Page 6, 2nd paragraph). Thus, it would be obvious to one of ordinary skill in the art to incorporate 0.005-0.05 mass% Nb as taught by JP’452 in the steel of Song in order to improve steel corrosion resistance as disclosed by JP’452. The amount of Nb disclosed by JP’452 overlaps the recited Nb amount in claim 2. 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. Thus, claim 2 is obvious over Song in view of JP’452.
Regarding claim 8, Song does not teach the recited amount of Ni. JP’452 teaches a martensitic stainless steel having major composition overlapping the composition disclosed by Song (See Abstract). JP’452 discloses that 0.1-0.6 mass% Ni stabilizes austenite during heat treatment (Page 5). Thus, it would be obvious to one of ordinary skill in the art to incorporate 0.1-0.6 mass% Ni as taught by JP’452 in the steel of Song in order to stabilize austenite during heat treatment as disclosed by JP’452.
Allowable Subject Matter
Claim 7 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.
Response to Arguments
Applicant's arguments filed 07/30/2026 have been fully considered but they are not persuasive.
First, the applicants argued that the Examiner asserts that Song (US 2023/0107193) discloses a hardness of 51.4 HRC, which corresponds to a tensile strength of 1820 to 1880 MPa. The present Claim 1 requires having a tensile strength of 1,800 MPa or less, which does not overlap with the Song's range.
In response, the recited tensile strength is close to the recited hardness. Further, Song discloses that the steel has hardness of 47-51 HRC ([0083]), which converts to a tensile strength of 1580-1820 according to Hardness Conversion Table and overlaps the recited tensile strength in claim 1. 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). Similarly, 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). See MPEP 2144.05 I. Thus, the recited tensile strength is a prima facie case of obviousness over Song.
Second, the applicants argued that the present application and Song are not inherently identical, because they differ in, for example, the conditions at the time of quenching (i.e., whether carbonitrides are retained). More specifically, according to the present invention, through appropriate processing, spherical precipitates do not completely disappear, and fine precipitates remain in the as-quenched state, whereby excellent hydrogen embrittlement resistance is obtained after the subsequent tempering treatment (see [0040]).
In response, Song discloses a method of making the steel comprising heating the steel at 840 ºC for 10 hours, lower the temperature to 580 ºC at a cooling rate of 15 ºC/h, then heating the steel at 1050 ºC for 1-30 minutes followed by quenching ([0051] to [0094]), which meets the processing conditions disclosed in instant Specification ( spheroidizing annealing at 820 ºC or more for 1 hour to 10 hours, cooling to 550-650 ºC at a cooling rate of 30 ºC/h or less, then heating the steel at a temperature of above austenite formation temperature but at 1200 ºC or lower for 10 minutes to 2 hours followed by quenching). Song discloses quenching conditions that meet the quenching conditions disclosed in instant Specification. Thus, the recited structure is inherent in Song.
Third, the applicants argued that Song clearly re-dissolves chromium carbonitrides into solid solution during the austenitizing process (because the precipitation temperature of Cr carbonitrides in Steel F is 937°C, whereas the austenitizing temperature is 1050°C). Furthermore, Steel F was not subjected to tempering.
In response, the dissolution temperature of Cr carbonitride is not equal to the precipitation temperature of Cr carbonitride. There is no evidence Cr carbonitrides dissolves at 1050°C.
Song discloses that tempering process is a step of imparting toughness to a martensite structure and the tempering process may be performed in a temperature range of 400 to 600° C for 30 minutes to 2 hours ([0079]). Thus, Song discloses a tempering process and it would be obvious to one of ordinary skill in the art to perform tempering after quenching in order to improve toughness as disclosed by Song.
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 Xiaowei Su whose telephone number is (571)272-3239. The examiner can normally be reached 8:00-5:00.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Hendricks can be reached at 5712721401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/XIAOWEI SU/Primary Examiner, Art Unit 1733
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