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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 submission filed on 03/09/2026 has been entered.
Status of Claims
Claims 1-9 are pending and presented for examination on the merits.
Claims 1 and 9 are currently amended.
Status of Previous Claim Rejections Under 35 USC § 112
The previous rejection of claim 9 under 35 U.S.C. § 112(b) is withdrawn in view of the amendments to the claim.
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 1-5 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over JP 2018-059188 (A) to Takayama et al. (“Takayama”) (abstract and computer-generated translation are attached).
Regarding claims 1, 2, and 8, Takayama discloses an abrasion-resistant steel sheet having a hardness of 460-590 HBW 10/3000 Brinell hardness (abstract; para. [0075], [0076]), which overlaps the claimed ranges. The steel sheet has been hot rolled and has a thickness ranging from 4 mm to 50 mm (hot-rolled strip product) (para. [0082], [0087]), which overlaps the claimed range.
The steel includes the following elements in percent by mass (abstract; para. [0048]-[0074]):
Element
Claim 1
JP 2018-059188 (A)
C
0.21 - 0.35
> 0.23 to 0.34
Si
0 - 0.5
0.05 - 1.00
Mn
0.15 - 0.30
0.05 - 2.00
Al
0 - 0.1
0.100 or less
Cu
0.1 - 0.4
0.01 - 1.00
Ni
0.2 - 0.9
0.01 - 5.00
Cr
0.2 - 0.9
0.05 - 0.90
Nb
0 - 0.005
0.005 - 0.025
Ti
0 - 0.035
0.005 - 0.030
V
0 - 0.05
0.01 - 1.00
B
0.0005 - 0.0050
0.0001 - 0.0018
P
0 - 0.025
0.020 or less
S
0 - 0.008
0.050 or less
N
0 - 0.01
0.0050 or less
Ca
0 - 0.01
0.0005 - 0.0100
Fe + inevitable impurities
remainder
remaining
Nb is an optional element and need not be added (zero percent), which falls within the claimed range. Para. [0060].
The transitional phrase “consisting of” is met by Takayama because any additional elements taught by Takayama not explicitly recited by the instant claim are optional and are therefore not required (i.e., can be zero percent). See MPEP § 2111.03(II). See Takayama at para. [0059], [0063], [0070].
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.
Regarding claims 3 and 4, Takayama teaches that the steel has improved toughness. Para. [0050], [0061], [0071]-[0073]. Takayama also teaches that the limiting bending radius R/t is 2.8 or less. Para. [0118]. However, Takayama is silent regarding a specific Charpy-V impact toughness and bending property as measured by the claimed conditions.
It is well established that when a material is produced by a process that is identical or substantially identical to that of the claims and/or possesses a structure or composition that is identical or substantially identical to that of the claims, any claimed properties or functions are presumed to be inherent. Such a finding establishes a prima facie case of anticipation or obviousness. See MPEP § 2112.01. In the present instance, Takayama teaches a steel that has a chemical composition, hardness, and microstructure (martensite) that meet the claimed invention. Therefore, any behavioral properties, such as impact toughness and bending radius, would also be expected in Takayama’s steels due to the likeness of their chemical and microstructural characteristics.
Regarding claim 5, Takayama discloses that the volume fraction of martensite is 90% or more, with the remainder being ferrite, pearlite, austenite, and bainite. Para. [0077].
Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Takayama, as applied to claim 1 above, and further in view of JP 2015-193873 (A) to Miura et al. (“Miura”) (abstract and computer-generated translation are attached).
Regarding claims 6 and 7, Takayama discloses that the steel is obtained by quenching from an austenitic state (para. [0089]), suggesting a prior austenite structure. Takayama is silent regarding a grain size of any prior austenite.
Miura is drawn to a steel plate excellent in abrasion resistance. Abstract. The steel contains an as-quenched microstructure phase and an old/prior austenite grain size of 25 µm or less. Abstract; para. [0040]. If the prior austenite grain size exceeds 25 µm, the low-temperature toughness will decrease. Para. [0043].
Therefore, it would have been obvious to one of ordinary skill in the art to have limited the prior austenite grain size to 25 µm or less in the martensitic steel of Takayama because a fine prior austenite grain size would ensure improved toughness of the steel, thereby supporting Takaya’s concern with maintaining good toughness.
Further regarding claim 7, Takayama and Miura are silent regarding the aspect ratio of prior austenite grains. However, the steel is subject to rolling processes at temperatures that meet the temperature parameters of claim 9 and the thicknesses as thin as 4 mm. Takayama at para. [0082], [0087]. The act of rolling would flatten the steel (reduce its thickness) and the grains therein. Thus, one of ordinary skill in the art would have expected the formation of elongated grains (an aspect ratio exceeding 1) in the steel sheets of Takayama when they are subject to rollers in the rolling process.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Takayama in view of Miura and further in view of JP 2007-224408 (A) to Hoshi et al. (“Hoshi”) (abstract and computer-generated translation are in file as of 05/01/2024).
Regarding claim 9, Takayama discloses a method of manufacturing a steel material. Para. [0084]. The method includes the following steps:
(i) creating a steel slab (providing a steel slab) (para. [0084]);
(ii) heating the slab to a temperature preferably 900oC or higher and 1250oC or lower (heating the steel slab to an austenitizing temperature of 1150-1300oC) (para. [0085], [0086]);
(iii) hot rolling the slab to a temperature of 850-1000oC (hot rolling to a desired thickness in the range of Ar3 to 1250oC) (para. [0087]);
(iv) direct quenching to a temperature below the Mf point (direct quenching the steel to a cooling end) (para. [0088], [0089], [0094], [0095]); and
(v) reheating the quenched steel to a tempering temperature of (Mf point-100oC) or higher to preferably (Mf point-10oC) or lower (optionally temper annealing at a temperature in the range of 150-250oC) (para. [0094], [0096]).
The steel composition includes the following elements in percent by mass (abstract; para. [0048]-[0074]):
Element
Claim 1
JP 2018-059188 (A)
C
0.21 - 0.35
> 0.23 to 0.34
Si
0 - 0.5
0.05 - 1.00
Mn
0.15 - 0.30
0.05 - 2.00
Al
0 - 0.1
0.100 or less
Cu
0.1 - 0.4
0.01 - 1.00
Ni
0.2 - 0.9
0.01 - 5.00
Cr
0.2 - 0.9
0.05 - 0.90
Nb
0 - 0.005
0.005 - 0.025
Ti
0 - 0.035
0.005 - 0.030
V
0 - 0.05
0.01 - 1.00
B
0.0005 - 0.0050
0.0001 - 0.0018
P
0 - 0.025
0.020 or less
S
0 - 0.008
0.050 or less
N
0 - 0.01
0.0050 or less
Ca
0 - 0.01
0.0005 - 0.0100
Fe + inevitable impurities
remainder
remaining
Nb is an optional element and need not be added (zero percent), which falls within the claimed range. Para. [0060].
The transitional phrase “consisting of” is met by Takayama because any additional elements taught by Takayama not explicitly recited by the instant claim are optional and are therefore not required (i.e., can be zero percent). See MPEP § 2111.03(II). See Takayama at para. [0059], [0063], [0070].
The steel sheet has been hot rolled and has a thickness ranging from 4 mm to 50 mm (hot-rolled strip product). Para. [0082], [0087].
Takayama teaches that hot rolling takes place within the temperatures of 850-1000oC (para. [0087]), but does not specifically identify the hot rolling finish temperature. However, Takayama discloses that direct quenching takes place from above an Ar3 quenching start temperature, suggesting that the finish rolling temperature falls somewhere within the claimed range of 800-960oC.
Miura is drawn to a steel plate excellent in abrasion resistance. Abstract. In a direct quenching process, the steel is quenched from a temperature of Ar3, with the hot rolling end (hot rolling finish) temperature being 800oC or higher, which is above the Ar3 transformation point. Para. [0049]. If the hot rolling completion temperature is too high, crystal grains will coarsen, so it is preferable to keep it below 950oC. Para. [0049].
It would have been obvious to one of ordinary skill in the art to have maintained a hot rolling finish temperature in Takayama above the above the Ar3 transformation point, such as 800-950oC as taught by Miura, because grain growth is controlled at these temperatures.
Takayama does not teach a step of coiling the steel.
Hoshi is directed to a hot-rolled steel sheet. Abstract. The steel sheet is made by hot rolling, cooling, and winding (penultimate paragraph of seventh page of translation). The winding (coiling) temperature is 300oC or less and is important for obtaining the martensitic structure (last paragraph of eighth page of translation).
It would have been obvious to one of ordinary skill in the art to have incorporated a coiling step in the process of Takayama because winding the strip into coiled form would make it easier to store lengthy strips in a compact space. In addition, it would have been obvious to have coiled at a temperature of 300oC or less in order to preserve the martensitic structure desired by Takayama.
Response to Arguments
Applicant’s arguments filed on 03/09/2026 have been considered but are moot because the new ground of rejection does not rely on US 2015/0225822 (A1) to Miura et al.
Conclusion
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/VANESSA T. LUK/Primary Examiner, Art Unit 1733
March 13, 2026