DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submissions filed on 10/30/2025 has been entered.
Status of Claims
Claims 1, 3-8, and 10-15 are pending and presented for examination on the merits.
Claims 1 and 8 are currently amended.
Claim Rejections - 35 USC § 112
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.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
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 of carrying out his invention.
Claims 1, 3-8, and 10-15 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Regarding claims 1 and 8, the limitation reciting that the yield strength (YS) of the cold-rolled steel sheet is 601.8 MPa or more is new matter because the specification as originally filed does not disclose this range. In Table 2 of the specification, Inventive Example 6 has a YS value of 601.8 MPa. However, single data points are discrete values only; they cannot define or create an open-ended range.
A range of 601.8 MPa or more includes all values greater than 601.8 MPa, such as 1500 MPa, which is not a YS value found in the specification. Even though the specification discloses some YS values exceeding 601.8 MPa (e.g., 853.6 MPa for Steel No. 20 in Table 2), these higher YS are associated with comparative examples and therefore not a part of the present invention.
Furthermore, it should be noted that the steels of the present invention have a yield ratio of 0.75 or less (page 10, lines 9-10). This means that the YS is not maximized but rather suppressed and balanced with the tensile strength value. Therefore, the YS cannot be limitless as claimed.
Regarding claims 3-7 and 10-15, the claims are likewise rejected, as they depend upon and incorporate the subject matter of rejected claims 1 and 8.
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 1 and 3-6 are rejected under 35 U.S.C. 103 as being unpatentable over US 2004/0238082 (A1) to Hasegawa et al. (“Hasegawa”) in view of KR 10-1049844 (B1) to Won et al. (“Won”) (computer-generated translation is in file as of 03/28/2023).
Regarding claims 1 and 3, Hasegawa discloses a method of manufacturing a cold-rolled steel sheet (method for manufacturing a cold-rolled steel sheet). Para. [0001]. The steel has excellent stretch-flangeability and is formable (excellent formability). Abstract; para. [0026], [0035], [0038].
The steel sheet includes the following elements in percent by mass (para. [0024], [0029]-[0036]):
Element
Claim 1
US 2004/0238082 A1
C
0.05 to 0.15
0.04 to 0.10
Si
0.2 to 1.5
0.5 to 1.5
Mn
2.2 to 3.0
1.8 to 3
P
0.001 to 0.10
0.02 or less
S
0.010 or less
0.01 or less
sol. Al
0.01 - 0.10
0.01 to 0.1
N
0.010 or less
0.005 or less
Fe and impurities
balance
balance
Using the midpoints of the ranges of Si and Mn, a calculated Si/(Mn+Si) ratio is 0.29 (=1.0/(2.4+1.0)) (satisfying a condition Si/(Mn+Si) ≤ 0.5). In addition, Steel Nos. 1 and 2 in Table 5 of the present invention have Si/(Mn+Si) ratios of 0.32 and 0.30, respectively, which fall within the claimed range.
The method includes the following steps:
(i) providing a steel slab that has been continuously cast and reheated (manufacturing a steel slab that has been continuously cast using molten steel) (para. [0040]);
(ii) finish hot rolling at a temperature from Ar3 to 870oC (finish hot rolling the heated steel slab at a temperature of Ar3 to Ar3+50oC) (para. [0040]);
(iii) coiling at a temperature of 620oC or less (coiling the hot-rolled steel sheet at a temperature of 600-750oC) (para. [0040]);
(iv) cold rolling at a reduction rate of 55% or more (cold rolling the coiled steel sheet at a cold reduction ratio of 40-70%) (para. [0041]);
(v) continuous annealing at a temperature of 750-870oC (continuously annealing the cold-rolled steel sheet at a temperature of Ac1+30oC to Ac3-30oC) (para. [0042]-[0044]);
(vi) primary cooling to 550-750oC (primary cooling the continuously annealed steel sheet to a temperature of 650-700oC) (para. [0045], [0046]); and
(vii) secondary cooling to a terminal temperature of 300oC or less (secondarily cooling the primary cooled steel sheet to Ms-50oC or lower) (para. [0047], [0048]).
The structure of the steel is substantially ferrite and martensite. Para. [0037]; claim 1. Martensite is 30-60% by volume fraction, depending on tensile strength desired. Para. [0038]. The steel has a dual-phase structure. Para. [0026]. Since the steel is dual-phase and substantially ferrite and martensite, then ferrite must be the remainder, i.e., about 30-70% by volume fraction, which overlaps the claimed range.
Bainite and austenite may be contained in an amount of less than 2% or less by volume as long as the steel is not deteriorated. Para. [0037]. (Austenite here is understood to be retained austenite that remains or has not been transformed, as suggested in para. [0046], [0048].) It therefore follows that the sum total of ferrite and martensite must be about 98% or higher, which falls within the claimed range. The transitional phrase “consisting of” is met by Hasegawa because no phases outside the claimed phases are required. See MPEP § 2111.03(II).
The steel may have a yield point that exceeds 600 MPa. See, for example, Table 2 (Steel Sheet No. 4/Steel No. 4); Table 6 (all present invention examples); and Table 8 (all present invention examples).
The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness. MPEP § 2144.05(I). It would have been obvious for one of ordinary skill in the art to select from among the prior art ranges because there is utility over an entire range disclosed in the prior art.
Hasegawa teaches continuously casting the slab, but does not specifically teach using soft reduction as claimed.
Won is directed to a method for reducing the center segregation of a cast slab by applying optimal pressure reduction during continuous casting. Page 1. A representative technique for reducing the occurrence of central segregation is soft reduction. Page 2 – middle of page; Fig. 1. Reducing central segregation is important because it ensures a uniform internal quality. Page 1 – last paragraph; pages 5-6 – bridging paragraph.
It would have been obvious to one of ordinary skill in the art to have used a soft reduction processing during continuous casting, as taught by Won, to make the slab of Hasegawa because it would produce a homogeneous slab with uniform distribution of elements (including uniform distribution of Mn), thereby providing a steel slab that is uniform in properties and behavior.
Hasegawa is silent regarding whether the steel sheet has low deviation of direction (claim 1), the percentage of Mn band within the martensite (claim 1), and whether the TS and YS values in their respective parallel and perpendicular rolling directions are within 50 MPa (claim 3). However, the method of Hasegawa in view of Won is identical or substantially identical to the claimed method. Therefore, any claimed properties or function, such as Mn band amount and uniformity of TS and YS in their respective parallel and perpendicular rolling directions, would be expected to be present in a steel produced by the combination of the prior art method. See MPEP § 2112.01.
It is noted that Won explicitly teaches the reduction of center segregation and a uniform internal quality. Page 1; page 2 – middle of page; pages 5-6 – bridging paragraph. Therefore, banding or segregation of elements, including Mn, would be expected to be minimized due to the uniformity of structure obtainable by Won’s method. This uniformity would also be expected to translate to uniform TS and YS mechanical properties in the directions parallel and perpendicular to the rolling directions due to the chemical and structural homogeneity of the slab.
Regarding claim 4, Hasegawa discloses that the steel may further contain Ti 0.001 to 0.05% by mass and/or Nb 0.001 to 0.05% by mass (para. [0036]), each of which falls within the claimed ranges.
Regarding claim 5, Hasegawa discloses that the steel may further contain Cr 0.01 to 1.0% by mass and/or Mo 0.01 to 0.5% by mass (para. [0036]), each of which overlaps the claimed ranges.
Regarding claim 6, Hasegawa discloses that the steel may further contain B 0.0001% to 0.0020% by mass (para. [0036]), which falls within the claimed range.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Hasegawa in view of Won, as applied to claim 1 above, and further in view of US 2011/0017363 (A1) to Kang et al. (“Kang”).
Regarding claim 7, Hasegawa does not teach the presence of Sb in the steel.
Kang is directed to a high-strength thin steel sheet having high tensile strength and possessing excellent plating characteristics. Abstract; para. [0006]. Sb is an indispensable element in the steel, as it secures excellent plating characteristics by suppressing surface oxides. Para. [0034].
Hasegawa notes that the steel sheet can be electroplated, hot-dip galvanized, or applied with solid lubricant. Para. [0051]. Therefore, it would have been obvious to one of ordinary skill in the art to have added Sb to the steel of Hasegawa so that the surface of the steel can be made more ready to receive a plating or coating.
Response to Arguments
Applicant is notified that claims 8 and 10-15 are not rejected under prior art but are rejected under 112(a) for the reasons set forth above.
Applicant’s arguments with respect to Ahn (WO 2007/067014 (A1)) have been considered, but they are moot because the new ground of rejection does not rely on Ahn to address the claims.
Conclusion
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/VANESSA T. LUK/Primary Examiner, Art Unit 1733
January 10, 2026