DETAILED ACTION
Status of Claims
Claims 1, 2, and 4-11 are pending and presented for examination on the merits.
Claim 1 is currently amended. Claims 10 and 11 are new.
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, 2, 4, 5, 8, 10, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over JP 2005-179783 (A) to Hashimoto et al. (“Hashimoto”) (abstract and computer-generated translation are attached).
Regarding claims 1, 2, 10, and 11, Hashimoto discloses a wear-resistant steel sheet having superior low-temperature toughness. Abstract. The steel sheet has been hot rolled to a desired thickness (hot-rolled steel strip product). Page 4 – last paragraph; p. 5 – second and third paragraphs.
The steel contains the following elements in percent by mass (p. 2 – last paragraph; p. 3): (Table appears on the next page.)
Element
Claim 1
JP 2005-179783 (A)
C
0.21 - 0.35
0.10 - 0.30
Si
0 - 0.5
0.1 - 1.0
Mn
0.15 - 0.30
0.1 - 2.0
Al
0 - 0.1
----------------------
Cu
0.1 - 0.4
0.1 - 1.5
Ni
0.2 - 0.9
0.1 - 2.0
Cr
0.2 - 0.9
0.1 - 1.5
Nb
0 - 0.005
0.005 - 0.1
Ti
0 - 0.035
0.005 - 0.05
V
0 - 0.05
0.01 - 0.5
B
0.0005 - 0.0050
0.0005 - 0.0025
P
0 - 0.025
0.02 or less
S
0 - 0.008
0.005 or less
N
0 - 0.01
harmful solute
Ca
0 - 0.01
----------------------
Fe + inevitable impurities
remainder
balance
Nb is an optional element and need not be added (zero percent), which falls within the claimed range. Page 3 – sixth and twelfth paragraphs.
The transitional phrase “consisting of” is met by Hashimoto because any additional elements taught by Hashimoto not explicitly recited by the instant claim are optional and are therefore not required (i.e., can be zero percent). Hashimoto at p. 3 – sixth paragraph. See MPEP § 2111.03(II).
The Brinell hardness HB is 360 or more (abstract; p. 2 – fourth paragraph), which encompasses the claimed ranges, with higher hardness values approaching 500 HB being achievable (FIG. 2).
The Charpy absorbed energy vE-40 at -40°C is 27 J or more (abstract; p. 2 – fourth paragraph), which encompasses the claimed ranges, with higher Charpy absorbed energy values approaching 190 J (FIG. 1).
Hashimoto does not explicitly disclose limiting the sum of Mn and Ni to no more than 1.05. However, when adding the endpoints of the ranges of Mn and Ni, their sum total ranges from 0.2 to 4.0, which overlaps the claimed range.
Additionally, Hashimoto discloses that the carbon equivalent (Ceq) should be 0.50% or less. Page 2 – fourth and fifth paragraphs. Ceq is equal to C + Mn/6 + (Cu+Ni)/15 + (Cr+Mo+V)/5. Formula (2). Since Mn and Ni are in the numerator of their respective addends, it follows that there is incentive to select Mn and Ni values from the lower end of their respective ranges in order to keep Ceq at or under 0.50. Thus, it would have been obvious to one of ordinary skill in the art to have kept the sum total of Mn and Ni relatively low, such as equal to or less than 1.05, in order to satisfy Formula (2).
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 claim 4, Hashimoto is silent regarding the bending property as claimed. 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, Hashimoto teaches a steel that has a chemical composition, hardness, and microstructure (martensite) that meet the claimed invention. Therefore, any behavioral properties, such as bending radius, would also be expected in Hashimoto’s steels due to the likeness of their chemical and microstructural characteristics.
Regarding claim 5, Hashimoto discloses that the structure is preferably mainly composed of martensite. Page 5 – fourth paragraph. The transitional phrase “consisting of” is met by Hashimoto because no additional phases are required, suggesting that the microstructure is entirely or substantially entirely martensitic. See MPEP § 2111.03(II).
Regarding claim 8, Hashimoto discloses a hot-rolled thickness of 9-50 mm (p. 6 – second and eighth full paragraphs), which overlaps the claimed range.
Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Hashimoto, 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 in the file as of 03/18/2026).
Regarding claims 6 and 7, Hashimoto discloses heating the steel to a temperature of 950-1250°C, e.g., 1150°C, prior to hot rolling (p. 5 – seventh paragraph; p. 6 – second full paragraph), which overlaps an austenitizing temperature of instant claim 9, suggesting austenitization and the formation of a prior austenite structure. Hashimoto is silent regarding a grain size of any prior austenite formed.
Miura is drawn to a steel plate excellent in abrasion (wear) 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].
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 Hashimoto because a fine prior austenite grain size would ensure improved toughness of the steel, thereby supporting Hashimoto’s concern with maintaining good toughness.
Further regarding claim 7, Hashimoto and Miura are silent regarding the aspect ratio of prior austenite grains. However, the steel is subject to a rolling process. Hashimoto at p. 4 – last paragraph; p. 5 – second and third paragraphs. 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 Hashimoto when they are subject to rollers in the rolling process.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Hashimoto 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 the file as of 05/01/2024).
Regarding claim 9, Hashimoto discloses a method of making a wear-resistant steel sheet having superior low-temperature toughness that has hot rolled to a desired thickness hot-rolled steel strip product (method for manufacturing a hot-rolled steel strip product). Abstract; p. 4 – last paragraph; p. 5.
The method includes a step of producing steel slab containing the following elements in percent by mass (providing a steel slab consisting of the chemical composition according to claim 1) (p. 2 – last paragraph; p. 3; p. 6 – second full paragraph): (Table appears on the next page.)
Element
Claim 1
JP 2005-179783 (A)
C
0.21 - 0.35
0.10 - 0.30
Si
0 - 0.5
0.1 - 1.0
Mn
0.15 - 0.30
0.1 - 2.0
Al
0 - 0.1
----------------------
Cu
0.1 - 0.4
0.1 - 1.5
Ni
0.2 - 0.9
0.1 - 2.0
Cr
0.2 - 0.9
0.1 - 1.5
Nb
0 - 0.005
0.005 - 0.1
Ti
0 - 0.035
0.005 - 0.05
V
0 - 0.05
0.01 - 0.5
B
0.0005 - 0.0050
0.0005 - 0.0025
P
0 - 0.025
0.02 or less
S
0 - 0.008
0.005 or less
N
0 - 0.01
harmful solute
Ca
0 - 0.01
----------------------
Fe + inevitable impurities
remainder
balance
Nb is an optional element and need not be added (zero percent), which falls within the claimed range. Page 3 – sixth and twelfth paragraphs.
The transitional phrase “consisting of” is met by Hashimoto because any additional elements taught by Hashimoto not explicitly recited by the instant claim are optional and are therefore not required (i.e., can be zero percent). Hashimoto at p. 3 – sixth paragraph. See MPEP § 2111.03(II).
Hashimoto does not explicitly disclose limiting the sum of Mn and Ni to no more than 1.05. However, when adding the endpoints of the ranges of Mn and Ni, their sum total ranges from 0.2 to 4.0, which overlaps the claimed range.
Additionally, Hashimoto discloses that the carbon equivalent (Ceq) should be 0.50% or less. Page 2 – fourth and fifth paragraphs. Ceq is equal to C + Mn/6 + (Cu+Ni)/15 + (Cr+Mo+V)/5. Formula (2). Since Mn and Ni are in the numerator of their respective addends, it follows that there is incentive to select Mn and Ni values from the lower end of their respective ranges in order to keep Ceq at or under 0.50. Thus, it would have been obvious to one of ordinary skill in the art to have kept the sum total of Mn and Ni relatively low, such as equal to or less than 1.05, in order to satisfy Formula (2).
Prior to hot rolling, the steel is heated to a temperature of 950-1250°C, e.g., 1150°C, prior to hot rolling (heating the steel slab to an austenitizing temperature of 1150-1300°C) (p. 5 – seventh paragraph; p. 6 – second full paragraph), which overlaps the claimed temperature.
The steel is hot rolled to a target plate thickness (hot rolling to a desired thickness). Page 4 – last paragraph; p. 5 – third paragraph.
After hot rolling, the steel may be quenched from the temperature above the Ar3 point without allowing it to cool (hot rolling at a temperature of Ar3 to 1250°C; direct quenching the hot-rolled steel strip product to a cooling end). Page 5 – fourth paragraph.
Hashimoto does not specifically identify the hot rolling finish temperature. However, Hashimoto teaches that the steel may be quenched from the temperature above the Ar3 point without allowing it to cool after hot rolling and an example hot rolling temperature of 900°C (p. 5 – third and fourth paragraphs; p. 6 – second full paragraph), 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 Hashimoto below 950oC as taught by Miura, because grain growth is controlled at these temperatures.
Hashimoto 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 Hashimoto 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 Hashimoto.
Claims 1, 2, 4, 5, 8, 10, and 11 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 in the file as of 03/18/2026).
Regarding claims 1, 2, 8, 10, and 11, Takayama discloses a 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].
Takayama does not explicitly disclose limiting the sum of Mn and Ni to no more than 1.05. However, when adding the endpoints of the ranges of Mn and Ni, their sum total ranges from 0.06 to 7.0, which overlaps the claimed range.
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 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.
Takayama discloses that the steel has an improved toughness (para. [0050], [0061], [0071]-[0073]), but is silent regarding a specific Charpy-V impact toughness.
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, would also be expected in Takayama’s steels due to the likeness of their chemical and microstructural characteristics.
Regarding claim 4, Takayama also teaches that the limiting bending radius R/t is 2.8 or less. Para. [0118]. However, Takayama is silent regarding a specific bending property as measured by the claimed conditions.
As previously noted above, Takayama teaches a steel that has a chemical composition, hardness, and microstructure (martensite) that meet the claimed invention. Therefore, any behavioral properties, such as bending radius, would also be expected in Takayama’s steels due to the likeness of their chemical and microstructural characteristics. See MPEP § 2112.01.
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 Miura.
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 Hoshi.
Regarding claim 9, Takayama discloses a method of manufacturing a steel material that has been hot rolled into a steel sheet having a thickness ranging from 4 mm to 50 mm (method of manufacturing a hot-rolled strip product). Para. [0082], [0084], [0087].
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].
Takayama does not explicitly disclose limiting the sum of Mn and Ni to no more than 1.05. However, when adding the endpoints of the ranges of Mn and Ni, their sum total ranges from 0.06 to 7.0, which overlaps the claimed range.
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]).
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 06/16/2016 have been fully considered, but they are not persuasive.
Applicant argues that the claimed invention is not obvious over Takayama because Takayama does not teach the claimed sum of at most 1.05 for Mn and Ni for attaining the Charpy-V impact toughness as claimed. Applicant states that Takayama teaches exceedingly broad ranges for Ni and that all of the compositional examples in Takayama contain Mn and Ni in total amounts that exceed 1.05, therefore not suggesting the claimed Mn+Ni range.
In response, specific examples and preferred embodiments cannot support a teaching-away type argument when the prior art discloses that broader ranges are acceptable. See MPEP § 2123(II). In the present instance, the Mn in Takayama can be as low as 0.10% and the Ni can be as low as 0.01%, if added. Takayama does not indicate that the lower end of the ranges of Mn and Ni cannot or should not be selected. Therefore, one of ordinary skill in the art would have understood that the Mn and Ni quantities of Takayama are not limited to the upper end of their respective ranges.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VANESSA T. LUK whose telephone number is (571)270-3587. The examiner can normally be reached Monday-Friday 9:30 AM - 4:30 PM ET.
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/VANESSA T. LUK/Primary Examiner, Art Unit 1733
August 20, 2026
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