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 .
Response to Amendment and Status of Claims
Applicant’s amendments to the claims, filed November 25, 2025, are acknowledged. Claim 1 is amended, and Claims 6-9 are cancelled. No new matter has been added.
Claims 11-13 remain withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, Group II, drawn to a manufacturing method, there being no allowable generic or linking claim. Applicant timely elected without traverse in the reply filed October 2, 2024.
Claims 1-5 and 11-13 are pending and Claims 1-5 are currently considered in this office action.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over Chung (previously cited, KR 102166592 B1, see updated English Machine Translation) in view of Kondo (previously cited, US 20100065166 A1) and Masoumi (“Improvement of wear resistance in a pearlitic rail steel via quenching and partitioning processing”).
Regarding Claim 1, Chung discloses a hot-rolled steel (Abstract; para. [0060]), comprising the following chemical elements in percentage by mass, of:
Element
Claim 1
Chung
Citation
C
0.35-0.45%
0.10-0.45%
Abstract; [0008]
Si
0.27-0.35%
0.05-1%
Abstract; [0008]
Mn
0.6-0.8%
0.15-3%
Abstract; [0008]
Al
0.015-0.05%
0-0.04%
Abstract; [0008]
V
0.06-0.1%
0-0.20%
Abstract; [0008]
Zr
0.3-0.70%
Silent (0%)
Mg
0.001-0.005%
0-0.005%
[0052]
P
0-0.025%
0-0.03%
Abstract; [0008]
S
0-0.015%
0-0.03%
Abstract; [0008]
N
0-0.005%
0-0.02%
Abstract; [0008]
O
0-0.001%
0-20ppm*
Abstract; [0008]
Fe
balance,
inevitable impurities
balance,
inevitable impurities
Abstract; [0008]
*see below
Chung discloses wherein oxygen is limited to 20ppm (0.002% or less) during melting, refining and casting (para. [0061]), but is silent towards the amount of oxygen in specifically the hot-rolled steel. However, one of ordinary skill in the art would appreciate oxygen to be similarly controlled to 20ppm or less (0.002% or less) in the hot rolled steel as well, as oxygen is not an intentionally added and is desired to be as low as possible (0%).
Additionally, Kondo teaches limiting O to 0.01% or less as an impurity in order to prevent toughness deterioration (para. [0065]-[0066]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have limited oxygen to 0.002% or less, as taught by Chung and Kondo, for the invention disclosed by Chung, in order to prevent the deterioration of the toughness (see teaching above).
Chung fails to disclose 0.3-0.7% Zr.
Kondo further teaches including up to 0.3% Zr in order to precipitate carbonitrides, thereby refining grain structure and improving toughness (para. [0076]-[0077]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included 0.30% Zr, which overlaps and reads on the claimed range 0.3-07% Zr, as taught by Kondo, for the invention disclosed by Chung, in order to form Zr carbonitrides, thereby refining grain structure and maximizing yield strength (see teaching above).
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.
Chung further discloses wherein a microstructure of the steel for the alloy structure is ferrite and pearlite (Abstract), and
wherein the yield strength is 650MPa or more, wherein the tensile strength is 850 MPa or more, and wherein an elongation is 19% or more (para. [0056]), which reads on the claimed range of 755 MPa or more yield strength, 900 MPa or more tensile strength, and an elongation of 12% or more.
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.
Chung fails to disclose an impact toughness of 100J or more.
Chung also fails to disclose the claimed ZrC, ZrN, MgO and MgS particles, and claimed amounts and sizes thereof.
However, Chung and Kondo disclose the claimed composition, and Chung in view of Masoumi (see below teaching) disclose substantially the same process as the instant invention.
Method:
Chung discloses melting in a furnace, refining to reduce oxygen to 20ppm, and casting (para. [0061]; reads on smelting, refining and casting; see instant specification para. [0044]).
Chung discloses forming and reheating a semi-finished billet to 1050-1250C and hot rolling with a rough mill (RM), intermediate roll (IM) and finishing mill (FM) (para. [0062]; reads on blooming (forming billet/bloom), cogging (rough roll) and secondary hot rolling (intermediate roll); see instant specification para. [0045]-[0046]). Chung teaches wherein 1050-1250C removes the segregation formed during casting, and one of ordinary skill in the art would appreciate that 1050-1250C would therefore be the heating temperature of forming, rough milling and intermediate milling unless otherwise specified in order to achieve this technical effect (see instant specification para. [0051]).
Chung discloses a final hot rolling with a finishing temperature of 837+ (50 to 100C), or 887-937C, followed by quenching and reheating to 550-650C (para. [0062], reads on heat treatment comprising a quenching temperature of 855-890 and tempering temperature of 645-670C; instant invention para. [0047] and para. [0052]).
Chung does not specify the cooling rate of the quenching step or the cooling rate during the tempering step.
However, Masoumi teaches wherein cooling rate affects the interlamellar spacing and colony size of pearlite, thereby affecting mechanical properties and wear resistance (Pg. 3, Results and Discussion, Para. 1). Thus, Masoumi teaches that the cooling rate is a result-effective variable, the effect being pearlitic colony size and interlamellar spacing, and therefore also being mechanical properties and wear resistance. Masoumi teaches cooling rates from the quench temperature and from the tempering temperature of 80C/s (Fig. 1), which reads on 50-90C/s (see para. [0052] of instant specification).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used a cooling rate for quenching and a cooling rate for the tempering step of 80C/s, as taught by Masoumi, for the invention disclosed by Chung, in order to control the pearlitic colony size and interlamellar spacing, thereby controlling the mechanical properties and wear resistance (see teaching above). Additionally, Masoumi demonstrates that the cooling rate is a result-effective variable (see above teaching and explanation), and it has been held that discovering an optimum value or a result effective variable involves only routine skill in the art (see 2144.05.I).
Thus, Chung and Masoumi teach the instant method, and Chung and Kondo teach the claimed composition, and one of ordinary skill in the art would appreciate the invention of Chung, Kondo and Masoumi to result in the claimed properties and microstructure, including the claimed impact toughness and the claimed precipitate types, amounts and sizes, because the composition and processes are the same.
When 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.
Regarding Claim 2, Chung fails to disclose at least one selected from the following chemical elements Ce, Hf, La, Re, Sc and Y, and wherein the total addition amount of these elements is 1% or less.
Kondo further teaches comprising up to 1.0% REM elements which include Sc, Y and lanthanoid elements, in order to improve hot workability (para. [0080]-[0081]). Elements La and Ce are lanthanoid elements. Kondo does not disclose Hf and Re, and these elements are considered 0%.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have included up to 1.0% REM elements, and therefore up to 1.0% total of Sc, Y, Ce, La, and Y, as taught by Kondo, for the invention disclosed by Chung, in order to improve hot workability (see teaching above).
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.
Regarding Claim 3, Chung discloses wherein the content by mass percentage of chemical elements satisfies at least one of the following:
0.08-0.1% V (para. [0035], 0-0.20% reads on the claimed range), and
0.001-0.003% Mg (para. [0052], 0-0.005% Mg reads on the claimed range).
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.
Regarding Claim 4, Chung and Kondo discloses wherein a ratio of the content by mass of chemical elements further satisfies at least one of the following:
Zr/N is 40-200 (Chung, para. [0041], 0-0.02% N; Kondo, para. [0076]-[0077], up to 0.3% Zr). For example, 0.30% Zr and 0.005% N gives a Zr/N ratio of 60, which reads on the claimed range).
Zr/V is 2-16.7 (Chung, para. [0035], 0-0.20% V; Kondo, para. [0076]-[0077], up to 0.3% Zr). For example, 0.30% Zr and 0.1% V gives a Zr/V ratio of 3, which reads on the claimed range.
Zr/C is 0.4-2.8 (Chung, Abstract, 0.1-0.45% C; Kondo, para. [0076]-[0077], up to 0.3% Zr). For example, 0.30% Zr and 0.40% C gives a Zr/C ratio of 0.75, which reads on the claimed range.
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.
Regarding Claim 5, Chung and Kondo discloses wherein a ratio of the content by mass of chemical elements further satisfies at least one of the following:
Mg/O is 0.5-3 (Chung, para. [0052], 0-0.005% Mg; Kondo, para. [0065]-[0066], comprising 0.01% or less O). For example, 0.0025% Mg and 0.001% O would give a ratio of Mg/O of 2.5, which reads on the claimed range.
Mg/S is 0.6-5.0 (para. [0052], 0-0.005% Mg; para. [0049], 0-0.03% S). For example, 0.0005% Mg and 0.005% S would give a ratio of Mg/S of 1, which reads on the claimed range.
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.
Response to Arguments
Applicant’s arguments, filed November 25, 2025, with respect to Claim 1, and dependent claims thereof, rejected under 35 U.S.C. 103 over Chung in view of Kondo and Horikami, have been fully considered and are persuasive in view of Applicant’s amendments to the claims which combine the limitations each of previous claims 6-9 into independent Claim 1. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made over Chung in view of Kondo and Masoumi, as detailed above.
Arguments directed to Horikami, Okonogi, Morohoshi, Yoshida, and Zheng are deemed moot in view of the new grounds of rejection.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Fujii (previously cited and cited by Applicant in IDS filed March 26, 2022, JP 2017145471 A, English Machine Translation provided): teaches an overlapping composition, including overlapping Zr/N and Zr/V ratios, and a TS of 590MPa or more, including strengths up to 1250 MPa (para. [0066]-[0085]; Claim 9, see Table 2, no. 41-43).
Kamata (previously cited, JP 10121200 A, English Machine Translation provided): teaches a hot-rolled steel comprising 0.20-0.50% C, 0.15-1.5% Si, 0.3-2.50% Mn, 0.005-0.05% Al, 0.01-030% V, 0-0.2% Zr, 0.005-0.02% N, a ferrite-pearlite microstructure, and a yield strength of 785MPa or more, a tensile strength of 930MPa or more, and an elongation of 8% or more (see para. [0011]; see Table 4 wherein elongations are greater than 12% for ferrite plus pearlite structures).
Yamamura (previously cited, JP 2001262287 A, English Machine Translation provided): teaches wherein TiN, TiC, MgO, MgS, VN, ZrN, ZrC and MnS (i.e., particles disclosed and taught by Kamata and Okonogi) exist in an austenitic stainless steel in an amount of 100 pieces/mm2 or more and with a 0.5-3um size, in order to provide solidification nuclei at the time of casting, thereby forming a finer casting structure and improving surface structure (Abstract; para. [0009]-[0010]).
Okonogi (previously cited and cited above, JP 2004250767 A, English Machine Translation provided, additional teachings): teaches including 0.005-0.05% S in order to form sulfides with Mg which act as pinning particles and improve machinability, and to suppress decarburization, while balancing for cold forgeability and toughness, and 0.0002-0.01% Mg in order to form the above described pinning sulfides, as well as to form pinning particles of oxides and composite inclusions of O and S, while balancing for production costs (para. [0025]; para. [0041]).
Yoshida (previously cited and cited above, US 20220325393 A1, additional teachings): teaches a similar steel (para. [0051]), wherein the steel comprises an impact toughness of 105J or more and therefore excellent low-temperature toughness and SSC (sulfide stress cracking) resistance, such that the steel material can be utilized in a severe environment such as a polar region (para. [0062] and para. [0004]; para. [0381]).
Yoshida further teaches including up to 0.01% rare earth elements (REM), including Sc, Y, La, in order to form sulfides to increase the sulfide stress cracking (SSC) resistance and to combine with P in order to suppress segregation of P at grain boundaries, thereby preventing decreases in low temperature toughness and SSC resistance (para. [0174]-[0175]).
Lee (previously cited, KR 20190061159 A, English Machine Translation provided): teaches a ferrite-pearlite steering rack bar comprising 0.40-050% C, 0.15-0.35% Si, 0.750.95% Mn, 0.001-0.03% P, 0001-0.025% S, 0.04-0.30% V, 0.01-003% Al, 0-0.01% N, 0-0.01% O and a balance of Fe and impurities, which comprises V carbonitrides, and further comprises a TS of 900MPa or more, an elongation of 19%, and an a impact strength of 90J/cm2 or more (Abstract; para. [0031]; para. [0038]; para. [0044]; para. [0072]). An impact toughness of 90J/cm2 assuming a standard Charpy impact specimen equates to an impact toughness of 72J or more.
Hasegawa (JP 2008240130 A, English Machine Translation provided): teaches a non-heat treated steel with a ferrite-pearlite structure, which includes 0.02-0.4% Zr in order to precipitate Zr carbides in addition to V carbonitrides, and further contribute to precipitation strengthening, thereby improving yield strength (para. [0048]).
Kushida (JP H10280037 A, English Machine Translation provided): teaches a martensitic steel and adding up to 0.5% Zr in order to improve yield strength, and therefore also SSC (stress corrosion cracking) resistance (para. [0038]).
Omura (JP 2018012856 A, English Machine Translation provided): teaches a martensitic steel with an overlapping composition, comprising B in order to improve the hardenability through the solid solution of B, and up to 1% Zr in order to form carbonitrides, thereby preventing the formation of BN and ensuring the solid solution of B is obtained (para. [0042]; para. [0030]). Omura further teaches a tensile strength of 850MPa or more (para. [0012]).
Mun (KR 20170072995 A; English Abstract and English Machine translation provided): teaches a ferrite-pearlite wire rod wherein carbonitrides sizes are 5-70nm, 80nm or larger carbonitrides are present in an amount of 5/um2 or less, and wherein the impact toughness is 100J or more (Abstract; see Table 3 impact value).
Horikami (previously cited, US 20160083823 A1): teaches a similar steel wherein the impact toughness is not less than 120J/cm2 for a 10mm sized Charpy impact test, which converts to an impact energy of 96J or more, in order to improve machinability of the steel bar and to prevent crack propagation (Abstract; see Table 3, impact values as high as 235J/cm2, or 188 J; para. [0038]; para. [0007]).
Okonogi (previously cited, JP 2004250767 A, English Machine Translation provided): teaches a similar range of S, Mg and O, wherein S forms sulfides with Mg which act as pinning particles which improve machinability, and wherein Mg also forms these pinning particles by forming Mg oxides and composite inclusions of O and S (para. [0025]; para. [0041]; para. [0044]).
Okonogi further teaches wherein Zr forms ZrC and ZrN in order to function in suppressing the coarsening of crystal grains (para. [0042]).
Morohoshi (previously cited, JP 2003064448 A, English Machine Translation provided): teaches wherein Mg sulfide-based and Mg oxide-based inclusions exist in amounts of at least 10 pieces/mm2 in order to refine the solidification structure and stably form pearlite, thereby preventing decreases in toughness (para. [0007] and para. [0001]).
Yoshida (previously cited, US 20220325393 A1): teaches a steel wherein 85% or more of precipitates are as large as 300nm (0.3um), in order to obtain high SSC (sulfide stress cracking) resistance and high tensile strength (Abstract; para. [0043]; Fig. 3-4). Particles comprising a size of 300nm reads on the claimed 0.2-7um size range.
Zheng (previously cited, WO 2019037749 A1; English Machine Translation provided): teaches wherein carbides and nitrides of Ti and V are formed in order to refine the grain structure, which is the same function that Ti, V and Zr serve for the steel of Chung in view of Kondo and in view of Okonogi (Kondo, para. [0077]; see Okonogi, para. [0037]-[0038]; para. [0040]; para. [0042]]; Zheng, para. [0035]-[0037], wherein Ti and V form V(N,C) and Ti (N,C)). Zheng teaches wherein the V(N,C) and Ti(N,C) are formed in an amount of 5-25 pieces/mm2 and 5-20 pieces/mm2 and wherein the V(N,C) are 0.2-5um and wherein Ti(N,C) are 0.1-8um (para. [0043]).
Zheng further teaches wherein MgO and MgS particles refine grain structure, contribute to crack mitigation during hot rolling, and improve low temperature impact toughness (para. [0042]). Zheng teaches wherein MgO and MgS particles are present in an amount of 5-25 pieces/mm2 (para. [0044]). Zheng teaches wherein MgO and MgS particles are 0.1-8um (para. [0043]).
Kadani (JP 2013076128 A): teaches a hot-rolled steel comprising 0.30-0.50% C, 0.10-1.00% Si, 0.20-1.50% Mn, 0.020% or less of P, 0.020% or less of S, 0.50-2.00% Cr, 0.10-1.00% Mo, 0.10-1.00% V, and 0.005-0.100% of sol.Al, with the balance of Fe and unavoidable impurities, and a ferrite + pearlite structure (Abstract).
Kadani teaches quenching from 870C and then tempering to achieve a impact toughness of 100J or more (para. [0045], [Refining condition 2]).
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 CATHERINE P SMITH whose telephone number is (303)297-4428. The examiner can normally be reached Monday - Friday 9:00-4:00 MT.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Walker can be reached on (571)-272-3458. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
CATHERINE P. SMITH
Patent Examiner
Art Unit 1735
/CATHERINE P SMITH/Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735