DETAILED ACTION
Response to Amendment
The Amendment filed 08/22/2025 has been entered. Claims 2-5, 8, 10-15, 19-20, and 22-25 remain pending in the application. New claims 22-25 have been added. Since new claims 22-23 and 25 are drawn towards a non-elected invention, claims 22-23 and 25 are withdrawn. Claims 10-15, 19-20, 22-23, and 25 have been withdrawn due to a restriction requirement. Claim(s) 1, 6-7, 9, 16-18, and 21 have been canceled. Applicant's amendments to the title and abstract have overcome the objections previously set forth in the Non-Final Rejection mailed 08/22/2025. Applicant's amendments to the claims have overcome the objections previously set forth in the Non-Final Rejection mailed 08/22/2025. Applicant's amendments to the claims have overcome the 112(b) rejections regarding the limitations “fine carbide particles”, “dispersive fine carbide particles”, “other unavoidable impurities”, “phase proportion of the tempered martensite” previously set forth in the Non-Final Rejection mailed 08/22/2025. Regarding the limitation “the carbide particles have a size of ≤60 nm” formerly in cancelled claims 7 and 17 and now present in currently amended claim 2, the Examiner acknowledges Applicant’s argument that the size refers to a particle diameter (remarks, page 9) and the 112(b) rejection previously set forth in the Non-Final Rejection mailed 08/22/2025 is withdrawn. Applicant's amendments to the claims have overcome the 112(d) rejections previously set forth in the Non-Final Rejection mailed 08/22/2025.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required:
Amended claim 2 now contains the limitation “wherein the carbide and carbonitride particles include MoC, VC, Nb(C, N).” The instant specification does not provide proper antecedent basis for the claimed subject matter, i.e., “carbide and carbonitride particles” (emphasis added). See 112(b) rejection for claim 2 regarding “carbide and carbonitride particles”.
Claim Interpretation
Regarding claim 2, the terms “has” and “have” in the limitations “has a matrix structure of ferrite + martensite” and “the chemical elements of the dual-phase steel plate have the following mass percentages” are interpreted as open-ended since additional elements are recited in “particles are precipitated in the matrix structure” of claim 2 and “further comprises 0.0015-0.003% of element B” of claim 3.
Transitional phrases such as "having" must be interpreted in light of the specification to determine whether open or closed claim language is intended. See, e.g., Lampi Corp. v. American Power Products Inc., 228 F.3d 1365, 1376, 56 USPQ2d 1445, 1453 (Fed. Cir. 2000) (interpreting the term "having" as open terminology, allowing the inclusion of other components in addition to those recited); Crystal Semiconductor Corp. v. TriTech Microelectronics Int’l Inc., 246 F.3d 1336, 1348, 57 USPQ2d 1953, 1959 (Fed. Cir. 2001) (term "having" in transitional phrase "does not create a presumption that the body of the claim is open"); Regents of the Univ. of Cal. v. Eli Lilly & Co., 119 F.3d 1559, 1573, 43 USPQ2d 1398, 1410 (Fed. Cir. 1997) (in the context of a cDNA having a sequence coding for human PI, the term "having" still permitted inclusion of other moieties). See MPEP 2111.03(IV).
Claim Rejections - 35 USC § 112
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 2-5, 8, and 24 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for a dual phase steel plate with the claimed coating, structure, particles, yield strength, tensile strength, elongation and hydrogen content, does not reasonably provide enablement for a dual phase steel plate with no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make the invention commensurate in scope with these claims.
There are many factors to be considered when determining whether there is sufficient evidence to support a determination that a disclosure does not satisfy the enablement requirement and whether any necessary experimentation is "undue." These factors include, but are not limited to:
(A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
In re Wands, 858 F.2d 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988)
The broadest reasonable interpretation of claims 2-5, 8, and 24 encompasses a dual-phase steel plate with a specific composition and mechanical properties, and which, after being soaked in hydrochloric acid for a time and under a predetermined stress, shows “no delayed cracking”. The specification discloses sufficient information for one of ordinary skill in the art to make the steel of the instant invention with the claimed composition, coating, particles, yield strength, tensile strength, elongation, and hydrogen content. However, the specification does not provide direction on how to obtain the claimed “no delayed cracking” property.
The instant specification recites comparative and inventive examples that shows steels with no cracking at various stress levels from 0.6*TS to 1.2*TS (Table 3, TS represents tensile strength). Table 1 of the instant specification recites the chemical composition of said comparative and inventive examples and Tables 2-1 and 2-2 recite various processing parameters such as soaking temperature, cold rolling reduction rate, coiling temperature, annealing temperature, etc. As best understood, comparative examples 1-6 have chemical compositions outside the claimed range as shown by underlining in Table 1, while comparative examples 7-14 are a steel M with chemical composition lying within the claimed ranges. In Table 2-1, comparative examples 7-10 have processing parameters outside those of the instant invention while comparative examples 11-14 are within the processing parameters of the instant invention. In Table 2-2, only comparative examples 11-14 are outside of the processing parameters of the instant invention. Based on Table 3, comparative examples 13 and 14 meet the claimed yield strength, tensile strength, elongation, “no delayed cracking”, and hydrogen content. Therefore, comparative examples 13-14 meet the claimed yield strength, tensile strength, elongation, “no delayed cracking”, and hydrogen content, and have chemical composition and processing parameters within those of the instant invention with the exception of a tempering temperature as shown by the underlining in Table 2-2. The instant specification does not clarify what is required, either in chemical composition or processing, to achieve the claimed no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength and therefore does not provide sufficient guidance for one of ordinary skill in the art to make the claimed steel.
At the time of filing, the state of the art was such that delayed cracking, also known as cold cracking, is recognized as an issue that occurs in the HAZ or under weld beads and therefore typically occurs during welding (Section C. Cold Cracking of "Embrittlement, Engineering Alloys" of Banerji; HAZ refers to the heat-affected zone and is a well-known term in the metallurgy arts). Banerji further teaches three factors are required for cold cracking: (1) pickup of hydrogen, (2) formation of a susceptible microstructure such as martensite, and (3) stress, which in the case of a weld can be provided by residual stresses. Additionally, the state of the art was such that it is recognized that cold cracking may be prevented by pre- or post-heating treatment similar to other welding processes (Cold cracking section of “Defect formation mechanisms and preventive procedures in laser welding” of Katayama, page 344).
While the claimed steel has martensite in its microstructure, the presence of martensite merely increases the susceptibility to delayed cracking and both increased hydrogen and stress are required for delayed cracking to occur, as taught by Banerji and Katayama. The examples provided in the specification do not clarify what chemistry or processing is required for the steel to meet the claimed “no delayed cracking” property, as discussed above. One of ordinary skill in the art would therefore have to experiment with many chemical compositions and processing parameters, including various heating treatments, before arriving at the claimed “no delayed cracking” property. Additionally, adding the hydrogen and stress required for delayed cracking would result in a product different to the claimed product (see 112(b) rejection below).
Thus, the disclosed guidance in the specification does not bear a reasonable correlation to the full scope of the claim. Taking these factors into account, undue experimentation would be required by one of ordinary skill in the art to practice the full scope of claims 2-5, 8, and 24.
Claims 2-5, 8, and 24 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 2 recites the limitation “wherein the carbide and carbonitride particles include MoC, VC, Nb(C, N)”. This limitation renders the claim indefinite since it is unclear whether both a carbide and a carbonitride particle must be included, or if including any of the claimed MoC, VC, Nb(C, N) would meet the limitation of “carbide and carbonitride particles”.
Claims 3-5, 8 and 24 are dependent on claim 2, do not resolve the aforementioned issues, and are thereby also indefinite.
Claim 2 recites the limitation “wherein the dual-phase steel plate has a matrix structure of ferrite + tempered martensite” which renders the claim indefinite. The term “matrix structure” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is unclear what the ferrite and tempered martensite distribution has to be within the steel microstructure to meet the limitation “has a matrix structure of ferrite+tempered martensite”. If the microstructure is >50 volume % tempered martensite, as is claimed in claim 5, the matrix structure of the claimed steel would be tempered martensite, not ferrite + tempered martensite.
Claims 3-5, 8 and 24 are dependent on claim 2, do not resolve the aforementioned issues, and are thereby also indefinite.
Regarding claim 2, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 2 recites the broad recitation “steel plate which is resistant to delayed cracking” (emphasis added), and the claim also recites “no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength” (emphasis added), which is the narrower statement of the range/limitation. The claim is considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. In this case, it is unclear whether the claimed steel plate encompasses any resistance to delayed cracking or only “no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength”.
Claims 3-5, 8 and 24 are dependent on claim 2, do not resolve the aforementioned issues, and are thereby also indefinite.
Claim 2 recites the limitation “no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength”. The term “pre-stress” renders the limitation indefinite since it is unclear what constitutes a “pre-stress” that would meet the claimed limitation. Applicant submitted that “pre-stress” refers to the static stretching stress applied to the steel sheet when testing for its cracking resistance in paragraph [0072] of the PG PUB (remarks, page 9). However, the paragraph referred to recites “A standard sample was prepared, and subjected to static stretching on a tensile testing machine to obtain a corresponding stress-strain curve. After data processing, the parameters of yield strength, tensile strength and elongation after fracture were obtained finally.” Therefore, the static stretching stress is applied for testing yield strength, tensile strength, and elongation, and not cracking resistance as argued by Applicant.
Claims 3-5, 8 and 24 are dependent on claim 2, do not resolve the aforementioned issues, and are thereby also indefinite.
Claim 2 recites the limitation “initial hydrogen content ≤ 3 ppm”. The term “initial” renders the claim indefinite since it is unclear whether the claimed “initial hydrogen content” is for the claimed steel plate, or for the steel plate at a different point in processing before arriving at the final steel plate that is claimed in the instant claims. A product may only be claimed at one point in time.
Claims 3-5, 8 and 24 are dependent on claim 2, do not resolve the aforementioned issues, and are thereby also indefinite.
Claim 2 recites the limitation “no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength”. This limitation renders the claim indefinite since soaking the claimed steel in hydrochloric acid would result in a steel different to the steel as claimed in amended claim 2. Applicant is attempting to claim a property of a different product, one after soaking the claimed steel in hydrochloric acid under a “pre-stress”, rather than the coated product as claimed. A product may only be claimed at one point in time.
Claims 3-5, 8 and 24 are dependent on claim 2, do not resolve the aforementioned issues, and are thereby also indefinite.
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 2-5 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0211413 A1 of Yang (as cited in prior Office action) in view of US 2019/0085427 A1 of Takashima (as cited in prior Office action), and further in view of “Kinetics of carbide formation for quenching and tempering steels during high-frequency induction heat treatment” of Lee and “Role of retained austenite in hydrogen trapping and hydrogen-assisted fatigue fracture of high-strength steels” of Malitckii.
Regarding claims 2-5 and 24, Yang teaches a high-strength coated steel sheet and a method for manufacturing the same (Abstract, high-strength steel sheet reads on the claimed ultra-high-strength steel plate). Yang teaches the coating layer is a galvanizing layer ([0072]) and that electroplating treatment may be performed for the coating treatment ([0095], a galvanizing layer by electroplating treatment reads on the claimed has an electro-galvanized coating).
Yang teaches the steel has a microstructure including a martensite phase and a ferrite phase, in which a volume fraction of the martensite phase is 50% to 80%, in which a volume fraction of tempered martensite with respect to the whole martensite phase is 50% or more and 85% or less ([0020], microstructure reads on the claimed matrix structure of ferrite+tempered martensite since the majority of the martensite phase of Yang is tempered martensite; since the microstructure is composed mainly of two phases, the microstructure of Yang also reads on the claimed dual-phase steel).
Yang therefore reads on the limitation an ultra-high-strength dual-phase steel plate and has an electro-galvanized coating, wherein the dual-phase steel plate has a matrix structure of ferrite + tempered martensite of claim 2.
List 1
Instant claims (mass %)
Yang (mass %)
C
0.07-0.1
0.05-0.15
Si
0.05-0.3
0.01-1.80
Mn
2.0-2.6
1.8-3.2
Cr
0.2-0.6
≤ 1.0
Mo
0.1-0.25
0.03-0.50 (one or more of a group)
Al
0.02-0.05
0.01-2.0
Nb
0.02-0.04
≤ 1 (one or more of a group)
V
0.06-0.2
≤ 1 (one or more of a group)
B
0.0015-0.003
0.0001-0.005 (one or more of a group)
One or more of:
B, Ti, Mo
Cu, Ni, Sn, As, Sb, Ca, Mg, Pb, Co, Ta, W, REM, Zn, Nb, V, Cs, and Hf
Unavoidable impurities
P ≤ 0.012
S ≤ 0.003
N ≤ 0.005
P: 0.05 or less
S: 0.02 or less
Fe
Balance
Balance (“and inevitable impurities”)
Tempered martensite
>50%
Martensite: 50-80 vol%
Tempered martensite: 50-85 vol% with respect to the whole martensite phase
Tempered martensite: 25-68 vol% (calculated from above)
Ferrite
“matrix structure of ferrite+tempered martensite”
30-50 vol%
Yield strength
≥ 550 MPa
550-800 MPa
Tensile strength
≥ 980 MPa
950-1200 MPa
Elongation after fracture
≥ 12%
14-22%
Yield ratio
0.55-0.70 (claim 24)
0.46-0.84 (calculated)
Yang teaches a steel with a chemical composition (claims 1-4, [0023]-[0025], [0031]-[0051]), microstructure (claim 1, [0020], [0023], [0062]-[0065]), yield strength (claim 1, [0073]), tensile strength ([0075]), and elongation ([0076]) overlapping with the claimed steel, as shown in List 1. While Yang does not explicitly disclose an overall phase fraction of tempered martensite, one can perform the calculation by calculating a 50-85% of tempered martensite from a 50-80 vol% of martensite, which results in values overlapping with the claimed ranges as shown in List 1. Regarding the yield ratio of claim 24, while Yang does not explicitly disclose a yield ratio, one can calculate the yield ratio using the disclosed yield strength and tensile strength of Yang. The yield ratio is interpreted as the ratio obtained from dividing the yield strength by the tensile strength. For example, a yield strength of 550 MPa divided by a tensile strength of 1200 MPa results in a yield ratio of 0.46. The resulting yield ratio values of Yang overlap with those of the claimed invention, as shown in List 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Yang therefore reads on the limitation the chemical elements of the dual-plate steel plate have the following mass percentages: C: 0.07-0.1%, Si: 0.05-0.3%, Mn: 2.0-2.6%, Cr: 0.2-0.6%, Mo: 0.1-0.25%, Al: 0.02- 0.05%, Nb: 0.02-0.04%, V: 0.06-0.2%, and a balance of Fe and unavoidable impurities of claim 2, wherein the properties of the dual-phase steel plate meet the following: yield strength ≥550 MPa, tensile strength ≥980 MPa, elongation after fracture ≥12% of claim 2, wherein the steel plate further comprises 0.0015- 0.003% of element B of claim 3, wherein the unavoidable impurities include elements P, S and N, and contents thereof are controlled to be at least one of the following: P ≤0.012%, S ≤0.003%, N ≤0.005% of claim 4, wherein a phase proportion by volume of the tempered martensite is >50% of claim 5, and wherein the yield ratio of the ultra-high-strength dual-phase steel is in the range of 0.55-0.70 of claim 24.
However, Yang does not explicitly disclose steel resistant to delayed cracking of claim 2, wherein distributed carbide and carbonitride particles are precipitated in the matrix structure, wherein the carbide and carbonitride particles include MoC, VC, Nb(C, N), wherein the carbide and carbonitride particles have a size of ≤ 60 nm, and wherein the carbide and carbonitride particles are all distributed in the matrix structure in a coherent form of claim 2, and wherein the properties of the dual-phase steel plate meet the following: initial hydrogen content ≤ 3 ppm; and no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength of claim 2.
Regarding the carbide particles of claim 2, Takashima is similarly concerned with a plated steel sheet with martensite and ferrite and teaches a steel sheet with similar composition to the steel sheet of Yang and is therefore considered analogous art.
Takashima teaches molybdenum, niobium, and vanadium form fine carbides in a steel sheet when added in the ranges, in mass%, of Mo: 0.05-0.50, Nb: 0.01-0.10, or V: 0.01-0.10% ([0070], [0073], [0074], fine carbides of Mo and V reads on claimed MoC and VC). While Yang does not explicitly disclose the formation of MoC, VC, or Nb(C,N), it is well known in the steel art, as taught by Takashima, that the addition of Mo, Nb, and V form fine carbides in steel when added in the ranges taught by Takashima. Since the steel sheet of Yang has overlapping Mo, Nb, and V contents with the composition of Takashima, one of ordinary skill in the art would reasonably expect the fine Mo, Nb, and/or V carbides of Takashima to necessarily be present and distributed in the steel sheet of Yang.
Yang therefore reads on the limitation wherein distributed carbide and carbonitride particles are precipitated in the matrix structure of claim 2 and wherein the carbide and carbonitride particles include MoC, VC, Nb(C, N) of claim 2.
Regarding the carbide size of claim 2, Takashima teaches “fine” carbides, but does not explicitly disclose the sizes of the Mo, Nb, and V carbides.
Lee teaches the size of carbides precipitated during quenching and tempering of steel (Abstract). Lee is considered analogous art since it is similarly concerned with steels that have a tempering step in their processing and teaches steels with similar carbon, chromium, and molybdenum content to the steels of Yang and the instant invention.
Lee teaches strong carbide formers such as Cr and Mo form nanosized, dispersed, and spheroidized carbides of “finer size” of 60-150 nm and that the steel with lower carbon content produced smaller carbides (Section 4 Conclusions). Lee teaches 0.2C-Cr consists of 0.2 wt% and 0.8 wt% Cr and 0.2C-Cr-Mo contains 0.2 wt% carbon with 1.1 wt% Cr and 0.2 wt% Mo, which have carbon and chromium contents slightly higher than the claimed upper limit of 0.1 mass% C and 0.6 mass% Cr. While the compositions are not overlapping, Lee teaches Mo carbide sizes of 60-150 nm and a trend that lower carbon content decreases carbide sizes.
Therefore, one of ordinary skill in the art would reasonably expect the “fine” carbides of modified Yang to have an approximate size of at most 60-150 nm, as taught by Lee.
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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Yang therefore reads on the limitation wherein the carbide and carbonitride particles have a size of ≤ 60 nm of claim 2.
Regarding the coherent form of the carbide particles of claim 2, since the steel sheet of modified Yang has a chemical composition, microstructure, and carbides overlapping with the claimed invention, as outlined above and in List 1, one of ordinary skill in the art would reasonably expect the steel sheet of modified Yang to necessarily possess the claimed carbides with the claimed coherent form.
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. “Products of identical chemical composition can not have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112.01 II. Therefore, it is expected that the steel of the prior art possesses the properties as claimed in the instant claims since a) the claimed and prior art products are identical or substantially identical in composition (see compositional analysis above in List 1), and b) the claimed and prior art products are identical or substantially identical in structure (see microstructure analysis above in List 1). Since the Office does not have a laboratory to test the reference alloy, it is applicant’s burden to show that the reference alloy does not possess the properties as claimed in the instant claims. See In re Best, 195 USPQ 430, 433 (CCPA 1977); In re Marosi, 218 USPQ 289, 292-293 (Fed. Cir. 1983); In re Fitzgerald et al., 205 USPQ 594 (CCPA 1980).
Modified Yang therefore reads on the limitation wherein the carbide and carbonitride particles are all distributed in the matrix structure in a coherent form of claim 2.
Regarding the initial hydrogen content of claim 2, it would have been necessary and obvious to look to the prior art for exemplary initial hydrogen contents in dual-phase steels with ferrite and martensite. Malitckii teaches hydrogen trapping in high-strength steels (Title). Malitckii is considered analogous art since it is similarly concerned with dual-phase steels and has tensile strengths overlapping with those of Yang and the instant invention. Malitckii teaches dual-phase steels with ferrite and martensite have a 3 ppm hydrogen content in their as-supplied condition (Section 2 Experimental, as-supplied condition reads on claimed “initial”). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to form the steel of Yang, and adjusting and varying the hydrogen content, such as within the claimed ranges, as taught by Malitckii, in order to form a conventional dual-phase steel using known and tested initial hydrogen content predictably suitable for dual-phase steels with a microstructure of ferrite and martensite.
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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Yang therefore reads on the limitation initial hydrogen content ≤ 3 ppm of claim 2.
Regarding the limitations “resistant to delayed cracking” and “no delayed cracking” of claim 2, the resistance to delayed cracking and “no delayed cracking” would result from the claimed composition and properties of the steel sheet recited in the body of claim 2. Since the steel sheet of modified Yang teaches a chemical composition, microstructure, tensile strength, yield strength, elongation, initial hydrogen content, carbides, and yield ratio overlapping with the claimed invention, as outlined above and shown in List 1, one of ordinary skill in the art would reasonably expect the steel sheet of modified Yang to necessarily possess the claimed “resistant to delayed cracking” and “no delayed cracking” limitations absent evidence to the contrary.
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. “Products of identical chemical composition can not have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112.01 II. Therefore, it is expected that the steel of the prior art possesses the properties as claimed in the instant claims since a) the claimed and prior art products are identical or substantially identical in composition (see compositional analysis above in List 1), and b) the claimed and prior art products are identical or substantially identical in structure (see microstructure analysis above in List 1). Since the Office does not have a laboratory to test the reference alloy, it is applicant’s burden to show that the reference alloy does not possess the properties as claimed in the instant claims. See In re Best, 195 USPQ 430, 433 (CCPA 1977); In re Marosi, 218 USPQ 289, 292-293 (Fed. Cir. 1983); In re Fitzgerald et al., 205 USPQ 594 (CCPA 1980).
Therefore, one of ordinary skill in the art would reasonably expect the steel sheet of modified Yang to necessarily possess the claimed “resistant to delayed cracking” and “no delayed cracking” limitations absent evidence to the contrary.
Modified Yang therefore reads on the limitations ultra-high-strength dual-phase steel plate which is resistant to delayed cracking and no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength of claim 2.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over US 2019/0211413 A1 of Yang (as cited in prior Office action) in view of US 2019/0085427 A1 of Takashima (as cited in prior Office action), “Kinetics of carbide formation for quenching and tempering steels during high-frequency induction heat treatment” of Lee and “Role of retained austenite in hydrogen trapping and hydrogen-assisted fatigue fracture of high-strength steels” of Malitckii, as applied to claim 2 above, and further in view of US 2018/0202019 A1 of Toda (as cited in prior Office action).
Modified Yang teaches the steel plate of claim 2 as described above.
Yang teaches a tempered martensite phase is a microstructure having a grain in which a large number of fine iron-based carbides and corrosion marks are observed ([0100], one of ordinary skill in the art understands ϵ carbides are iron-based carbides).
Yang therefore reads on the limitation wherein the tempered martensite further comprises carbide of claim 8.
However, Yang does not explicitly disclose wherein the tempered martensite further comprises coherently distributed ϵ carbide of claim 8.
Toda is similarly concerned with a plated steel sheet (Title) and teaches a steel with a composition ([0023]-[0030], [0042]-[0085]), microstructure ([0023]-[0030]), tensile strength ([0086]-[0087], Examples in Tables 7-8), and elongation (Examples in Tables 7-8) overlapping that of Yang and the instant invention.
Toda teaches adding ϵ-type carbides to a steel sheet improves delayed fracture resistance and has a coherent interface between the carbide and iron (Abstract, [0038], [0137]-[0140]). Toda teaches tempered martensite is an aggregate of lath-shaped crystal grains and includes the iron-based carbide therein which includes an ϵ-type carbide when heat treated ([0096]). Toda further teaches ϵ-type carbides form in appropriate ranges when a cooling stop temperature is between 80°C to 550°C ([0173]). Toda teaches an average major axis of the iron-based carbides may be 5 nm and 350 nm ([0023], [0028]).
Since the steel sheet of modified Yang teaches an overlapping composition, microstructure, the presence of iron-based carbides, as described above, and a cooling stop temperature of 400-600°C ([0026]), which overlaps with the cooling stop temperature of Toda to obtain ϵ-type carbides in coherent form, one of ordinary skill in the art would reasonably expect the steel sheet of modified Yang to necessarily possess the claimed coherently distributed ϵ carbides since the carbides in the steel sheet of Yang would form coherent ϵ carbides due to the cooling stop temperature used in the processing of Yang.
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. “Products of identical chemical composition can not have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). See MPEP § 2112.01 II. Therefore, it is expected that the steel of the prior art possesses the properties as claimed in the instant claims since a) the claimed and prior art products are identical or substantially identical in composition (see compositional analysis above), b) the claimed and prior art products are identical or substantially identical in structure (see microstructure analysis above), and c) the claimed and prior art products are produced by identical or substantially identical processes (Toda teaches coherent ϵ carbides are obtained when using a cooling stop temperature which overlaps with the cooling stop temperature taught by Yang). Since the Office does not have a laboratory to test the reference alloy, it is applicant’s burden to show that the reference alloy does not possess the properties as claimed in the instant claims. See In re Best, 195 USPQ 430, 433 (CCPA 1977); In re Marosi, 218 USPQ 289, 292-293 (Fed. Cir. 1983); In re Fitzgerald et al., 205 USPQ 594 (CCPA 1980).
Yang, as modified by Toda, therefore reads on the limitations wherein the tempered martensite further comprises coherently distributed ϵ carbide of claim 8.
Response to Arguments
Applicant's arguments filed 11/20/2025 have been fully considered but they are not persuasive.
Applicant argues that one of the objects is to provide an electro- galvanized ultra-high-strength dual-phase steel plate that is resistant to delayed cracking and in contrast, Yang provides a high-strength coated steel sheet, and a method for manufacturing thereof, which has high strength represented by yield strength of 550 MPa or more and with which it is possible to form a resistance spot weld zone having high torsional strength under the condition of high-speed deformation (remarks, page 10). Applicant further argues that the technical problem to be solved in Yang is completely different from what is disclosed in the instant application (remarks, page 10).
In response, in order for a reference to be proper for use in an obviousness rejection under 35 U.S.C. 103, the reference must be analogous art to the claimed invention. In re Bigio, 381 F.3d 1320, 1325, 72 USPQ2d 1209, 1212 (Fed. Cir. 2004) and a reference is analogous art to the claimed invention if: (1) the reference is from the same field of endeavor as the claimed invention (even if it addresses a different problem); or (2) the reference is reasonably pertinent to the problem faced by the inventor (even if it is not in the same field of endeavor as the claimed invention) (emphasis added). See MPEP 2141.01(a)(I). In this case, Yang and the instant invention recite their steels are used in the automotive industry and are therefore in the same field of endeavor and Yang is considered analogous art.
Furthermore, the reason or motivation to modify the reference may often suggest what the inventor has done, but for a different purpose or to solve a different problem. It is not necessary that the prior art suggest the combination to achieve the same advantage or result discovered by applicant. See MPEP 2144 (IV). In this case, Yang and the instant invention are both steels with overlapping chemical composition, microstructure, yield strength, tensile strength, and elongation, as described in the 35 U.S.C. 103 rejections in this Office action and summarized in List 1, and Yang and the instant invention are in the same field of endeavor since they are both steels used in the automotive industry.
Applicant argues that Yang is silent in resistance to delayed cracking of its steel while keeping a desired YS, TS and elongation after fracture, nor suggest any technical solution for this problem (remarks, page 11). Applicant further argues the steels of Comparative Examples 1-6 in Table 1 demonstrate that element composition is not the only factor determining the final properties of a steel, and thus not all the steels of Yang would have the claimed properties at the same time (remarks, page 11).
In response, since the steel sheet of modified Yang teaches a chemical composition, microstructure, tensile strength, yield strength, elongation, initial hydrogen content, carbides, and yield ratio overlapping with the claimed invention, as outlined above and shown in List 1, one of ordinary skill in the art would reasonably expect the steel sheet of modified Yang to necessarily possess the claimed “resistant to delayed cracking” and “no delayed cracking” limitations, as outlined in the 35 U.S.C. 103 rejection in this Office action. Furthermore, it is unclear from the instant disclosure how one arrives at the claimed “no delayed cracking” property as claimed in view of the 112(a) and 112(b) rejections in this Office action.
Regarding the argument that not all the steels of Yang would have the claimed properties, Table 3 shows Examples 1-6 and Comparative Examples 13-14 which meet the claimed yield strength, tensile strength, elongation, “stress level” related to the claimed “no delayed cracking”, and initial hydrogen content. It is unclear what the difference in either composition or processing is between the steel of Yang and the instant invention that would result in the steel of Yang not possessing the claimed “no delayed cracking”. The full scope of Yang's invention covers whole ranges of chemical alloying components and process parameters. A reference may be relied upon for all that it would have reasonably suggested to one having ordinary skill in the art, including nonpreferred embodiments. See MPEP 2123. In this case, not all steels of Yang need to have the claimed properties at the same time, but the full scope of Yang includes steels with the claimed properties absent evidence to the contrary.
Applicant argues that Yang's deficiencies are not cured by Takashima, as Takashima does not disclose a steel product, and/or method of manufacturing thereof, with a resistance to delayed cracking, and Takashima also suggests that Cr, Mo, Nb and V are optional elements (see paragraphs [0069]-[0070] and [0073]-[0074] of Takashima) (remarks, page 11).
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In this case, the teachings of Yang and not of Takashima are relied on for the chemical composition, as shown in List 1 of this Office action. Furthermore, examples and preferred embodiments are not evidence of teaching away when acceptable broader ranges are taught by the prior art. See MPEP 2123(II). In this case, the Cr, Mo, Nb, and V contents of Takashima overlap with those of Yang and the instant invention and therefore Takashima and Yang are considered analogous art since they are similarly concerned with a plated steel sheet and have overlapping compositions.
Therefore, modified Yang reads on the steel as claimed, as outlined in the 35 U.S.C. 103 rejection in this Office action, and would necessarily read on the claimed “no delayed cracking” despite not explicitly measuring or disclosing this property.
Conclusion
Cancelled claims 9 and 18 recited “wherein its properties meet at least one of the following: yield strength 550 MPa, tensile strength >980 MPa, elongation after fracture >12%, initial hydrogen content <3 ppm; no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength” (emphasis added). Amended claim 2 now recites “wherein the properties of the dual-phase steel plate meet the following: yield strength 550 MPa, tensile strength 980 MPa, elongation after fracture 12%, initial hydrogen content 3 ppm; and no delayed cracking when soaked in 1 mol/L hydrochloric acid for 300 hours under a pre-stress of greater than or equal to the tensile strength”.
Since amended claim 2 now requires all of the claimed properties instead of at least one of the properties, 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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/M.A./Examiner, Art Unit 1733
/REBECCA JANSSEN/Primary Examiner, Art Unit 1733