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
Receipt is acknowledged of a certified copy of JP 2019-232430 filed December 24, 2019 as required by 37 CFR 1.55. Receipt is also acknowledged of a copy of WO 2021/131445, the WIPO publication of PCT/JP2020/043310 filed November 20, 2020.
Claim Status
This Office Action is in response to Applicant’s Remarks filed September 24, 2025 and Claims filed June 3, 2025, which were examined in the June 27, 2025 Non-Final Office Action.
Claims Filing Date
June 3, 2025
Amended
1
Pending
1-8
Response to Remarks filed September 24, 2025
Endo ‘866 in view of Kushida
Applicant’s arguments, see Remarks p. 2 para. 2, filed September 24, 2025, with respect to Endo ‘866 in view of Kushida have been fully considered and are persuasive. The rejection of Endo ‘866 in view of Kushida has been withdrawn.
The applicant persuasively argues the September 4, 2025 interview agreed the rejection based on Kushida was overcome (Remarks p. 2 para. 2).
The claimed composition contains “Ti: 0.046-0.20%”, but Kushida discloses 0 to 0.03% Ti ([0040]) regulates the TiN size and amount ([0021]).
Endo ‘989 in view of Kakihara
Applicant’s arguments, see Remarks p. 5 para. 2, filed September 24, 2025, with respect to Endo ‘989 in view of Kakihara have been fully considered and are persuasive. The rejection of Endo ‘989 in view of Kakihara has been withdrawn.
The applicant argues Kakihara teaches C-based inclusions (abstract) that would not be expected to satisfy the claimed inclusion composition (Remarks p. 5 para. 2).
Kakihara discloses 0.02 to 0.06% C (Kakihara [0014]), whereas Endo ‘989 Steel Nos. C-F have 0.0075% C (Endo ‘989 Tables 1-2).
Endo ‘989 in view of one of Kikuchi or Maruyama
Applicant's arguments filed September 24, 2025 with respect to Endo ‘989 in view of one of Kikuchi or Maruyama have been fully considered but they are not persuasive.
The applicant argues Endo teaches 0.0350% or less C increases sensitivity to sulfide stress corrosion (SSC) cracking (Endo [0027]), 11.8-14.5% Cr provides corrosion resistance (Endo [0034]), and 1.8 to 3.0% Mo obtains corrosion resistance for a severe corrosive environment (Endo [0036]), but
Kikuchi discloses a lower limit of 0.08% C and an upper limit of 1.0% Cr and Maruyama a lower limit of 0.05% C, an upper limit of 5.0% Cr, and an upper limit of 1.0% Mo (Remarks para. spanning pp. 3-4, p. 4 paras. 2-3).
In the pending rejection, Endo ‘989 discloses a high-strength seamless stainless steel pipe ([0002], [0010]) with a composition and yield strength within the scope of the claim (Table 1-2 Steel Nos. C-F, [0042], [0044]). The rejection is in view of one of Kikuchi or Maruyama. Kikuchi discloses the claimed number density of inclusions (Kikuchi [0012], [0014], [0017]-[0018], [0037], [0039]-[0040]) improves toughness, ductility, and shape fixability (Kikuchi [0012], [0037]) with reduced segregation (Kikuchi [0014]) and improved cleanliness (Kikuchi [0039]). This disclosure is not related to the C and/or Cr contents of Kikuchi. Maruyama discloses the claimed number density of inclusions (Maruyama [0071]-[0074]) to prevent cracking from trapped diffusible hydrogen after welding (Maruyama [0072]-[0073]). The inclusions of Maruyama are oxide inclusions (Maruyama [0074]), which not related to the C, Cr, and/or Mo contents. Therefore, applicant’s arguments directed to alleged C, Cr, and/or Mo differences do not appear to be related to the obviousness of the claimed number density of inclusions.
The applicant argues Kikuchi discloses alumina-based inclusions ([0017]) that do not include Ti (Remarks p. 5 para. 3) and that TiN precipitates are different from alumina-based inclusions and would not be expected to satisfy the claimed inclusion composition (Remarks p. 5 para. 3) and Maruyama is directed to oxide inclusions that contain Ti as the main component ([0074]), but are non-obvious due to composition differences (Remarks para. spanning pp. 5-6).
As previously mentioned, in the pending rejection Endo ‘989 reads on the claimed inclusion composition (Endo ‘989 Tables 1-2 Steel Nos. C-F).
While Kikuchi may mention alumina-based inclusions during casting ([0017]), Kikuchi also mentions Ti- and V-based precipitates ([0016], [0030]-[0033]) and sulfide and oxide inclusions spheroidized by Mg and Ca ([0035]). Further, Kikuchi limits “the total number density of inclusions and precipitates” ([0012], [0014], [0017]-[0018], [0037], [0039]-[0040]). Therefore, the disclosure of Kikuchi applies to all inclusions and precipitates, such that it renders obvious limiting the number density of the inclusions of Endo ‘989.
Alternatively, with respect to Maruyama, the disclosed oxide inclusions contain Ti, Al, Mg, and Ca ([0074]), all the elements recited in applicant’s claimed inclusion composition.
The applicant argues the claimed inclusions are obtained by measuring oxygen during manufacturing and changing the amounts of added Ti and N ([0053]), where Steel Pipe Nos. 13 and 14 have an incorrect amount of added Ti and N and do not achieve the claimed inclusions (Remarks p. 6 para. 2), but the applied references are silent regarding controlling the addition of Ti and N during manufacturing based on measured oxygen value (Remarks p. 6 para. 3).
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., measuring oxygen during manufacturing and changing the amounts of added Ti and N) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Determination of patentability is based on the product itself. The claim is unpatentable even though the prior product was made by a different process. MPEP 2113(I). Therefore, even if the product of Endo ‘989 in view of one of Kikuchi or Maruyama was made by a different process, the prior art discloses a high-strength seamless stainless steel pipe with a composition and inclusions that render that claimed obvious. Kikuchi reduces inclusions during steelmaking by preventing excessive vertical flow of molten steel in the mold during casting (Kikuchi [0013]), center segregating reduction treatment (Kikuchi [0014]), limiting the time between slab removal from the furnace and completed cooling (Kikuchi [0016]), and stirring the molten steel (Kikuchi [0017]). Alternatively, Maruyama discloses controlling oxygen ([0101]-[0102]), Ca, and REM ([0123]-[0124]) to control oxide inclusion density. Therefore one of ordinary skill in the art would understand how to achieve the disclosed number density of inclusions in Endo ‘989
The applicant argues claims 1 and 4 require 0.046-0.20% Ti, whereas Arai teaches an upper limit of 0.040% Ti to prevent Ti nitride coarsening and decrease of SSC resistance (Remarks p. 7 para. 4).
Arai discloses the obviousness of an average prior austenite grain diameter of 5 um or less (Arai [0040]-[0041], [0046]-[0047], [0113]-[0114], [0147], [0151]) has a low SSC resistance and increased strength (Arai [0040]-[0041], [0114]). This disclosure is not related to the Ti content of Arai.
For the above cited reasons the rejection of Endo ‘989 in view of one of Kikuchi or Maruyama is maintained.
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 1-3 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Endo ‘989 (WO 2018/179111 with citations from US 2019/0241989) in view of one of Kikuchi (JP 2010-024522 machine translation) or Maruyama (US 2017/0350434).
Regarding claim 1, Endo ‘989 discloses a high-strength seamless stainless steel pipe for oil well ([0002], [0010]) having a composition and yield strength that fall within the scope of that claimed (Tables 1-2 Steel Nos. C-F).
Element
Claim 1
Endo ‘989 Steel No. C
Endo ‘989 Steel No. D
Endo ‘989 Steel No. E
Endo ‘989 Steel No. F
C
0.002 – 0.05
0.0075
0.0075
0.0075
0.0075
Si
0.05 – 0.50
0.200
0.200
0.200
0.200
Mn
0.04 – 1.80
0.40
0.40
0.40
0.40
P
0.030 or less
0.015
0.0015
0.0015
0.015
S
0.002 or less
0.0010
0.0010
0.0010
0.0010
Cr
11.0 – 14.0
13.20
12.30
12.00
12.20
Ni
3.0 – 6.5
6.25
6.00
5.70
5.70
Mo
0.5 – 3.0
2.550
2.850
2.550
2.600
Al
0.005 – 0.10
0.020
0.040
0.040
0.040
V
0.005 – 0.20
0.015
0.015
0.015
0.015
Ti
0.046 – 0.20
0.05
0.05
0.05
0.05
Co
0.01 – 1.0
-
-
-
-
N
0.002 – 0.15
0.0085
0.0075
0.0075
0.0075
O
0.010 or less
-
-
-
-
Fe
Balance
Balance
Balance
Balance
Balance
Cu
-
2.40
1.80
0.40
1.60
Nb
-
0.01
0.005
0.005
0.005
Ti/(Ti+Al+Mg+Ca)
>0.5 to <1.0
0.7
0.6
0.6
0.6
Yield strength
655 MPa or more
851
846
829
863
Cr+0.65Ni+0.6Mo
+0.55Cu-20C
≥ 15.0
20.0
18.8
17.3
18.2
Cr+Mo+0.3Si-43.3C-0.4Mn-Ni-0.3Cu-9N
≤ 11.0
8.3
8.1
8.2
8.1
The inventive examples of Endo ‘989 are silent to Co: 0.01 to 1.0%.
Endo ‘989 discloses 0.45% or less Co ([0042], [0044]).
It would have been obvious to one of ordinary skill in the art in Endo ‘989 Steel Nos. C-F to include 0.45% or less Co to improve pitting corrosion resistance without deteriorating toughness and increasing material cost (Endo ‘989 [0044]). 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).
Endo ‘989 is silent to the number density of inclusions having a major axis 5 um or more of 0.5 per mm2 or more and 3 per mm2 or less.
Kikuchi discloses a steel ([0001], [0009]) having a number density of inclusions having a major axis 5 um or more of 0.5 per mm2 or more and 3 per mm2 or less (30 pieces/mm2 or less, including 10 pieces/mm2 or less in a surface layer) ([0012], [0014], [0017]-[0018], [0037], [0039]-[0040]).
It would have been obvious to one of ordinary skill in the art in the steel of Endo ‘989 to limit the inclusions having a diameter of 5 um or more in the steel to 30 pieces/mm2 or less including to 10 pieces/mm2 or less in a surface layer to ensure good toughness and high levels of ductility and shape fixability (Kikuchi [0012], [0037]) with reduced segregation (Kikuchi [0014]) and improved cleanliness, such that it is not likely for cracks to occur (Kikuchi [0039]). 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).
Alternatively, Maruyama discloses a steel ([0024]) having a number density of inclusions having a major axis 5 um or more (3 um or more) of 0.5 per mm2 or more and 3 per mm2 or less (0.1 to 8.0 pieces/mm2) ([0071]-[0074]).
It would have been obvious to one of ordinary skill in the art in the steel of Endo ‘989 to limit the inclusions having a diameter of 3 um or more in the steel to 0.1 to 8.0 pieces/mm2 because an oxide inclusion having a diameter of 3 um or more functions as a trap site in which diffusible hydrogen in a metal lattice of weld metal just after welding is trapped, such that it can suppress flowing of diffusible hydrogen into a porosity, controlling internal pressure and preventing a crack (Maruyama [0072]-[0073]). 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 2, Endo ‘989 discloses one or two kinds selected from Cu: 0.05-3.0% and W: 0.05-3.0% (Table 1 Steel No. C: 2.40% Cu, D: 1.80% Cu, E: 0.40% Cu, F: 1.60% Cu).
Regarding claims 3 and 5, Endo ‘989 discloses one kind or two or more kinds selected from Nb: 0.01-0.20%, Zr: 0.01-0.20%, B: 0.0005-0.01%, REM: 0.0005-0.01%, Ca: 0.0005-0.0025%, Sn: 0.02-0.20%, Ta: 0.01-0.1%, and Mg: 0.002-0.01% (Table 1 Steel No. C: 0.01 % Nb).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Endo ‘989 (WO 2018/179111 with citations from US 2019/0241989) in view of one of Kikuchi (JP 2010-024522 machine translation) or Maruyama (US 2017/0350434) as applied to claim 1 above, and further in view of Arai (U.S. 2019/0226063).
Regarding claim 4, Endo ‘989 is silent to an average prior austenite grain diameter of 40 um or less.
Arai discloses a steel for an oil well ([0001], [0014]) having an average prior austenite grain diameter of 40 um or less (5 um or less) ([0040]-[0041], [0046]-[0047], [0113]-[0114], [0147], [0151]).
It would have been obvious to one of ordinary skill in the art in the steel of Endo ‘989 to have a prior austenite (gamma, γ) grain size as fine as less than 5 um for a low SSC resistance with increased strength (Arai [0040]-[0041], [0114]). 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).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Endo ‘989 (WO 2018/179111 with citations from US 2019/0241989) in view of Kikuchi (JP 2010-024522 machine translation) or Maruyama (US 2017/0350434) as applied to claim 2 above, and further in view of Arai (U.S. 2019/0226063).
Regarding claim 6, Endo ‘989 is silent to an average prior austenite grain diameter of 40 um or less.
Arai discloses a steel for an oil well ([0001], [0014]) having an average prior austenite grain diameter of 40 um or less (5 um or less) ([0040]-[0041], [0046]-[0047], [0113]-[0114], [0147], [0151]).
It would have been obvious to one of ordinary skill in the art in the steel of Endo ‘989 to have a prior austenite (gamma, γ) grain size as fine as less than 5 um for a low SSC resistance with increased strength (Arai [0040]-[0041], [0114]). 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).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Endo ‘989 (WO 2018/179111 with citations from US 2019/0241989) in view of one of Kikuchi (JP 2010-024522 machine translation) or Maruyama (US 2017/0350434) as applied to claim 3 above, and further in view of Arai (U.S. 2019/0226063).
Regarding claim 7, Endo ‘989 is silent to an average prior austenite grain diameter of 40 um or less.
Arai discloses a steel for an oil well ([0001], [0014]) having an average prior austenite grain diameter of 40 um or less (5 um or less) ([0040]-[0041], [0046]-[0047], [0113]-[0114], [0147], [0151]).
It would have been obvious to one of ordinary skill in the art in the steel of Endo ‘989 to have a prior austenite (gamma, γ) grain size as fine as less than 5 um for a low SSC resistance with increased strength (Arai [0040]-[0041], [0114]). 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).
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Endo ‘989 (WO 2018/179111 with citations from US 2019/0241989) in view of one of Kikuchi (JP 2010-024522 machine translation) or Maruyama (US 2017/0350434) as applied to claim 5 above, and further in view of Arai (U.S. 2019/0226063).
Regarding claim 8, Endo ‘989 is silent to an average prior austenite grain diameter of 40 um or less.
Arai discloses a steel for an oil well ([0001], [0014]) having an average prior austenite grain diameter of 40 um or less (5 um or less) ([0040]-[0041], [0046]-[0047], [0113]-[0114], [0147], [0151]).
It would have been obvious to one of ordinary skill in the art in the steel of Endo ‘989 to have a prior austenite (gamma, γ) grain size as fine as less than 5 um for a low SSC resistance with increased strength (Arai [0040]-[0041], [0114]). 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).
Related Art
Endo ‘814 (US 2020/407814)
Endo ‘814 discloses a stainless steel pipe for oil and gas ([0002]) with an overlapping composition and yield stress ([0016]-[0048]) and nitride inclusions ([0038]), where the composition is controlled to reduce the initiation point of sulfide stress corrosion cracking ([0042]).
Yuga (US 2019/0024201)
Yuga discloses a steel pipe for oil ([0001]) with nitride inclusions having a size of 4 um or more at a number density of 100 or less per 100 mm2, a prior austenite grain size number of 8.5 or more ([0010], [0013], [0019], [0043], [0049]-[0050]), and an overlapping composition and yield strength ([0012]-[0014], [0019]-[0042]).
Soma (US 2014/0205487)
Soma discloses an oil-well steel pipe ([0001]-[0002]) with controlled Ti and Nb carbo-nitride and nitride inclusions to obtain excellent SSC resistance ([0028]-[0031], [0077]-[0082]) and an overlapping composition ([0042]-[0076]).
Oka (JP 2000-328201 machine translation)
Oka discloses a martensitic stainless steel material used for oil well tubular goods ([0001], [0005]) with the density of precipitates closely related to the contents of Ti, Al, and N ([0007], [0018]-[0020], Fig. 1). The martensitic stainless steel of Oka has an overlapping composition ([0008]-[0022]) with 100 or less precipitates/mm2 ([0008], [0024]) mainly composed to Ti nitrides ([0023]-[0024]) with a major axis of 0.5 um or more ([0027]).
Kimura (JP 2001-294991 machine translation)
Kimura discloses a stainless steel ([0001]) containing appropriate amounts of Ti and Mg so that Mg-based inclusions covered with TiN are formed ([0011], [0030], [0034]) having a maximum diameter of 0.05 to 5 um at a density of 3 inclusions/mm2 or more ([0012], [0030]) for 0.0005 to 0.01% Mg, 0.01 to 0.8% Ti, and 0.0005 to 0.03% N ([0012], [0021], [0023]).
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.
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/STEPHANI HILL/Examiner, Art Unit 1735