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 .
Status of Claims
Amendment of the claims filed on 06/26/2026 has been entered.
Claims 1, 5-6, and 14-15 have been amended.
The amendments of claim 1 finds support on the page 4 of the instant specification of the disclosure, therefore, no new matter is presented.
The amendments of claims 5-6, and 14-15 do not find support in the instant specification of the disclosure, therefore, new matter has been presented.
Claim 9 is cancelled.
Claims 1-8, and 10-15 are remaining for examination on the merits.
Status of Previous Rejections
The previously cited Specification Objection has been withdrawn as Applicant submitted the amended page of the disclosure.
The previous 35 USC § 112(b) rejection of the claim 1 has been withdrawn due to the amendment of claim 1. The previous 35 USC § 112(b) rejections of the claims 2-4, 7-8, and 10-13 also been withdrawn due to the amendment and their dependency on claim 1.
The previous 35 USC § 112(b) rejections of the claims 5-6, and 14-15 have been maintained as the amendments did not find support in the specification.
The previously cited 35 USC § 103 rejections of the claims have been withdrawn due to the amendment of claim 1.
Claim Rejections - 35 USC § 112 (a)
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.
Claim 5 and 14 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. Both of these claim recites a new limitation “based on a thickness of the hot metal ladle top slag”, however, process on the page 4 of the instant specification of the disclosure, describes “KR desulfurization is adopted, after which 70% to 80%, such as 3/4, of the top slag in the hot metal ladle is removed”, wherein there is no description about “the top slag in the hot metal ladle is removed based on a thickness of the hot metal ladle top slag”.
Appropriate corrections are required.
Claim 6 and 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. Both of these claim recites a new limitation “of a total molten steel volume”, however, process on the page 5 of the instant specification of the disclosure, describes “during the tapping process, when the tapping amount reaches 1/6 to 1/4, such as 1/5, lime is added to the steel ladle in an amount of 1.6 to 3 kg/t steel; and when the tapping amount reaches 4/5 or more, such as 9/10,”, wherein there is no description about “the tapping amount is a percentage of a total molten steel volume”.
Appropriate corrections are required.
Claim Rejections - 35 USC § 112 (b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 5-6 and 14-15 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.
Claims 5 and 14, recite the limitation “70% to 80% of a hot metal ladle top slag is removed” in line 3, renders the claim indefinite, because it is unclear what is the basis of measuring the percentage, and how this percentage has been measured or calculated, instant Specification does not provide any guideline about this limitation, for example whether it is the percentage of total amount of the slag, or percentage of volume or percentage of thickness, or percentage of molten iron surface as some prior art previously cited Zhao Jiaqi, et.al. [CN112921148A] (machine translation) (Zhao hereafter) teaches slag removal is performed to expose percentage of the molten iron surface ((see. step 1 and step 3 Zhao’s claim 1, and [0010]), and/or previously cited pertinent prior art Yang Kehzhi, et.al. [CN112342333A] (machine translation, original provided in the IDS) teaches the percentage of the bright surface of the slag removal (see Yang’s claim 2). As the limitation is unclear, this limitation is not considered during the examination purpose.
With respect to claim 14, claim recite the limitation “75%” in line 3, renders the claim indefinite same reason shown above for the claim 5.
Appropriate corrections are required.
Claims 6 and 15 recite the limitation “a tapping amount reaches 1/6 to 1/4” in line 5, and then “the tapping amount reaches 4/5 or more” in line 6, both the limitations render the claim indefinite, because it is unclear what is the basis of measuring the fraction of the slag, and how this fraction has been measured or calculated, instant Specification does not provide any guideline about this limitation, for example whether it is the fraction of total amount of the slag, or fraction of volume or fraction of thickness, as some prior art as shown in the rejection section Hu Hantao, et.al. [CN109402321A] (machine translation, original provided in the IDS) (Hu’321A, hereafter) teaches that the slag thickness of a steel ladle is smaller than or equal to 50 mm in the steel tapping process, 2.0-5.0 kg of lime is added into per ton of steel in the early stage of steel tapping, 0.5-2 kg of an Al quality modification agent is added in per ton of steel at the last stage of steel tapping (see Hu’321A’s abstract). As the limitation is unclear, this limitation is not considered during the examination purpose.
With respect to claim 15, claim recite the limitation “a tapping amount reaches 1/5” in line 3, and then “the tapping amount reaches 9/10 or more” in line 4, both the limitations render the claim indefinite same reason shown above for the claim 6.
Appropriate corrections are required.
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 1-8, 10-11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Hu Hantao, et.al. [WO2021036974A1] (machine translation) (Hu hereafter) and in view of Yang Kehzhi, et.al. [CN112342333A] (machine translation, original provided in the IDS)) (Yang hereafter).
Regarding claim 1, Hu discloses a method for preparing a titanium-containing ultra-low-carbon steel, comprising (the production of titanium-containing ultra-low carbon steel, the process path adopted in this invention is as follows: [0048]) hot metal pretreatment, primary converter refining, vacuum refining, continuous casting, hot rolling, pickling and cold rolling (hot metal desulfurization and dephosphorization - converter decarburization - steel tapping, ladle top slag modification - vacuum decarburization, Ti deoxidation, Al addition and composition fine-tuning - addition of rare earth metals - continuous casting - hot rolling - pickling - cold rolling see Hu’s claim 7, [0048]);
wherein in the vacuum refining, after decarburization is completed, then Al is added for deoxidization treatment, after which a circulation time of the molten steel is ≥ 3 min (After RH vacuum decarburization is completed, then Al is added, and then the molten steel is circulated for ≥3 minutes, see Hu’s claim 1, and in an example, the molten steel is circulated for 9 minutes after Al is added, see Hu’s [0050])); then additional alloying and rare earth components are added to the molten steel, after which a circulation time of the molten steel is ≥ 2 min (add other alloying elements and/or adjust the composition of molten steel according to the finished product specifications, and circulate the molten steel for ≥2 minutes, see Hu’s claim 1, after adding rare earth elements, the molten steel was circulated for 5 minutes, see Hu’s [0050]), wherein an oxide of Re2O3· Al2O3 is finally generated in the molten steel; and the vacuum refining is completed (Rare earth metals Ce and/or La are added to the molten steel, and oxides Ce2O3· Al2O3 and/or La2O3· Al2O3 are finally generated in the molten steel, achieving smooth casting, see Hu’s claim 1).
Therefore, both of Hu’s circulation time is within the range as recited in the instant claim.
Hu further teaches in the smelting of ultra-low carbon steel, the oxygen (free oxygen and combined oxygen that is added during converter smelting) is the main oxygen source in the entire smelting process ([0003]).
But Hu is silent about “after decarburization is completed, a free oxygen content in molten steel is 100 to 350 ppm”.
However, Yang teaches a high-efficiency, low-oxygen, ultra-low-carbon steel production method employs a process of hot metal pretreatment desulfurization, converter smelting, argon blowing station, RH refining, and continuous casting (see Yang’s claim 1, 2). Yang then teaches the forced decarburization process and oxygen blowing decarburization begins during the vacuuming process; after oxygen blowing and the vacuum level, the oxygen content in the steel at the decarburization endpoint is maintained ≤300 ppm; after decarburization, oxygen is determined, and aluminum particles are added for deoxidation based on the oxygen determination result; after the aluminum particles are added, pure circulation is performed for 2-4 minutes, followed by alloying, (see Yang’s claim 7, [0014]) and the oxygen content in the decarburization endpoint steel is controlled at 138–276 ppm (see Yang’s claim 8, [0015]).
Yang’s disclosed free oxygen content after the decarburization is within the as recited in the instant claims.
Yang teaches controlling of oxygen content to provide a high-efficiency, low-oxygen, ultra-low-carbon steel production method to simplify converter and RH treatment tasks, and improve production efficiency and steel cleanliness (see Yang’s [0007]) and low oxygen level control throughout the smelting process effectively reduces the accumulation of ultra-low carbon steel during casting, improves the castability of the molten steel, and reduces the incidence of defects in the steel zone of cold-rolled products (see Yang’s [00019]).
Yang’s process is directed to the production of ultra-low-carbon steel and therefore, analogous to the instant claim and Hu.
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Yang’s teachings of maintaining a free oxygen content in molten steel after the decarburization to modify Hu’s method to produce a defect free clean steel product with high quality with higher production efficiency.
Regarding Claim 2, all the discussions above claim 1 are applicable for claim 2 in addition, Hu discloses in the vacuum refining,
before the decarburization treatment, the free oxygen content in the molten steel is adjusted to satisfy a mass ratio O/C=1.96 (after converter blowing, [%C] = 280ppm, [%O] = 550ppm; before vacuum treatment, and the vacuum decarburization started [0050], therefore calculated O/C = 550/280 = 1.96).
Hu’s disclosed mass ratio O/C is within the as recited range of the instant claim.
It is to be noted, claim recites “and/or” in between three different limitations, and use of “or” make these limitations as optional and not required by the claim language. Therefore, with a teaching of mass ratio O/C, Hu already meet the entire claimed limitation.
In addition, Hu also discloses the rare earth component comprises Ce or La, and is added in an amount based on a mass ratio REM/T.O=0.8-2.6, wherein REM represents a mass of the rare earth component added in kg, and T.O represents a total oxygen amount in the steel in ppm (the rare earth metal is composed of Ce and/or La see Hu’s claim 2, 3, and [0013], [0014], Hu defines a ratio of rare earth addition mass (kg) to total oxygen in steel (ppm) REM/T.O see [0012] and [0030] and the value of REM/T.O = 0.8-2.6 see Hu’s claim 6 and [0017], and an example REM/T.O = 1.35 [0050]).
Hu’s mass ratio a mass ratio of REM/T.O is within the as recited range of the instant claim.
Hu teaches there are two possible adverse consequences: 1) the generated single rare earth oxide has a high specific gravity and is not easy to float and 2) the content of free Re, in the steel increases sharply, reacts with the refractory material, contaminates the molten steel, and in severe cases, can lead to the melting and loss of the stopper rod or nozzle, resulting in abnormal
casting or interruption, therefore, the REM/T.O within the disclosed limit is required ([0030]).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Hu’s teachings in view of Lyu to produce a defect free steel product with high quality without any refractory material contaminants.
Hu further teaches a content of impurities other than rare earth element(s) in the rare earth component is < 0.1 wt.%, wherein a total oxygen amount T.O is < 100 ppm, and a N content is ≤ 30 ppm, as Hu teaches a mass percentage of the rare earth metal composition is: Ce 60-70%, La 30-40%, (see Hu’s claim 3 and [0019]), therefore, Hu’s composition does not contain any oxygen and nitrogen, and it would have expected to have those about zero and therefore, meet the limitations.
Regarding Claim 3, all the discussions above claim 1 and 2 are applicable for claim 3, wherein Hu already discloses the oxide of Re2O3· Al2O3 is Ce2O3· Al2O3 or La2O3· Al2O3 (Rare earth metals Ce and/or La are added to the molten steel, and the molten steel is circulated for ≥2 min, and oxides Ce2O3· Al2O3 and/or La2O3· Al2O3 are finally generated in the molten steel, achieving smooth casting, see Hu’s claim 1, [0019]).
Regarding Claim 4, all the discussions above claim 1 and 2 are applicable for claim 4 wherein Hu already discloses a vacuum refining device used for the vacuum refining is an RH furnace or a VD furnace or a VOD furnace (RH vacuum decarburization see Hu’s claim 1) Hu further teaches a vacuum refining device is Ruhrstahl-Heraeus (RH) furnace (see Hu’[0019]).
Regarding Claim 5, all the discussions above claim 1 are applicable for claim 5 in addition, Hu discloses the hot metal pretreatment, desulfurization is adopted (hot metal desulfurization, see Hu’s claim 7).
But Hu is silent about the “KR desulfurization is adopted, after which 70% to 80% of a hot metal ladle top slag is removed; and/or a S content in the hot metal after the desulfurization is ≤ 20 ppm”.
Yang teaches in the hot metal pretreatment, KR desulfurization is adopted, and a S content in the hot metal after the desulfurization is ≤ 800 ppm (≤0.003%) (the hot metal pretreatment desulfurization can be performed using the KR method, resulting in an S content ≤ 0.0080% after desulfurization, see Yang’s [0021]).
Yang’s disclosed S content in the hot metal after the desulfurization is overlapping with the as recited in the instant claims.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected and produced S content in hot metal from the teachings of Lyu that falls within the instantly-claimed ranges, because “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].
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Yang’s teachings to modify Hu’s method to control sulfur content.
It is to be noted, claim recites “and/or” in between the two different limitations, and use of “or” make these limitations as optional and not required by the claim language. Therefore, with a teaching of S content in the hot metal after the desulfurization, Yang meet the entire claimed limitation.
Regarding Claim 6, all the discussions above claim 1 are applicable for claim 1 in addition, Hu discloses in the primary converter refining, blowing is stopped, the free oxygen content in the molten steel is ≤ 500 ppm (after converter blowing, [%O] = 550ppm, see Hu’s [0050]), which is within the as recited in the instant claim.
But Hu is silent about a top-bottom combined blowing process is adopted.
Or, Hu is silent about “during tapping, when a tapping amount reaches 1/6 to 1/4, lime is added to a steel ladle in an amount of 1.6 to 3 kg/t steel; and when the tapping amount reaches 4/5 or more, aluminum slag is added to the steel ladle in an amount of 1.0 to 1.4 kg/t steel”.
Or, Hu teaches after the tapping is completed, a composition of a steel ladle top slag is adjusted to: FeO+MnO ≤ 7.0wt% (before vacuum treatment, the ladle top slag composition (%FeO) + (%MnO) ≤ 6.50, [0050]), which is within the as recited in the instant claim. But Hu is silent about the CaO=40 to 50wt%.
Yang teaches a high-efficiency, low-oxygen, ultra-low-carbon steel production method employs a process of hot metal pretreatment desulfurization, converter smelting, argon blowing station, RH refining, and continuous casting. The process, after desulfurization, the scrap steel is charged into the converter has a hot metal and the blowing method is top and bottom combined blowing, with a blowing time from 0 to 16 minutes, the final oxygen content in the converter is 200 to 400 ppm see Yang’s claim 1, 2 [0021]).
Yang’s disclosed free oxygen content is within the as recited in the instant claim.
Yang also teaches after the tapping is completed, a composition of a steel ladle top slag is adjusted to the CaO=50-60% (top slag modifier containing 40%-50% metallic aluminum by mass percentage, with the remainder being CaO (i.e. 50-60%), see Yang’s claim 1, 2 [0021]), and FeO+MnO content is 5.2%–7.8% 7.0wt% (a top slag modifier is added to the argon blowing station to ensure that the FeO+MnO content in the top slag is ≤8% by mass percentage (see Yang’s claim 1, 2 [0021]), and the FeO+MnO content is 5.2%–7.8% by mass percentage see Yang’s claim 5, [0021]).
Yang’s disclosed slag composition overlaps with the as recited in the instant claim.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected oxygen content and a slag composition from the teachings of Yang that falls within the instantly-claimed ranges, because “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].
Yang further teaches an efficient low-oxygen ultra-low carbon steel production method employs a bottom-blown and combined-blown (top and bottom) converter with a reasonable iron-to-steel ratio which achieves efficient, low-oxygen steel tapping from the converter, along with good top slag reduction. It reduces blowing losses and deoxidizer consumption during the blowing process. The molten steel enters the station with low oxygen levels (RH), and a single forced decarburization treatment mode is used, simplifying RH operation, improving processing efficiency, and significantly enhancing the cleanliness of the molten steel. Low oxygen level control throughout the smelting process effectively reduces the accumulation of ultra-low carbon steel during casting, improves the castability of the molten steel, and reduces the incidence of defects in the steel zone of cold-rolled products (see Yang’s [0019] and [0021].
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Yang’s teachings to modify Hu’s method to controlling oxygen content to produce a defect free clean steel product with high quality with higher production efficiency.
It is to be noted, claim recites “and/or” in between the two different limitations, and use of “or” make these limitations as optional and not required by the claim language. Therefore, with a teaching of free oxygen content and/or slag composition Yang meet the entire claimed limitation.
Regarding Claim 7 and 8, all the discussions above claim 1 are applicable for claim 7 and 8 in addition, Hu discloses the titanium-containing ultra-low-carbon steel comprises the following composition in mass percentage (Hu’s Claim 1) and the claimed composition has been shown in the following table for the comparison.
Element
Instant Claim 7 (mass %)
Instant Claim 8 (mass %)
Hu's composition wt. % [Hu’s Claim 1]
Within/Overlapping Range
C
≤ 0.005%
≤ 0.0018%
≤ 0.005%
Within/overlapping
Si
≤ 0.05%
≤ 0.03%
≤ 0.05%
Within/ overlapping
Mn
0.05 to 0.3%,
0.07 to 0.15%,
0.05 to 0.3%,
Within/ overlapping
Al
0.04 to 0.15%
0.04 to 0.0.07%
0.02 to 0.1%
Overlapping/ overlapping
Ti
0.04 to 0.1 %
0.04 to 0.06 %
0.008 to 0.05 %
Overlapping/ overlapping
P
≤ 0.05%
≤ 0.015%
≤ 0.05%
Within/ overlapping
S
≤ 0.02%
≤ 0.005%
≤ 0.02%
Within/ overlapping
N
N ≤ 0.003%
N ≤ 0.003%
N ≤ 0.003%
Within/ overlapping
Relation to Al and Ti
Al content is greater than a Ti content
Al content is greater than a Ti content
Al content ≥ Ti content
Within/ Within
Fe and unavoidable impurities
Balance
Balance
Balance
Overlapping / overlapping
Hu’s composition for all elements is overlapping with the as recited in the both of the instant claims.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected and produced a composition from the teachings of Hu that falls within the instantly-claimed ranges, because “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].
Hu further teaches the steel types applicable to the invention are ultra-low carbon steel products, i.e., carbon content ≤ 0.005 wt.%, and Al content ≥ Ti content in the molten steel composition, so as to ensure that the final deoxidation of the molten steel before addition of rare earth is controlled, by Al in the molten steel (Hu’s [0027]).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Hu’s teachings in view of Lyu to produce a titanium containing ultra-low carbon steel products with defect free and high quality without any rare earth refractory material contaminants.
Regarding Claim 10, all the discussions above claim 1 are applicable for claim 10 in addition, Hu discloses during the continuous casting, a pass rate of the mold liquid level fluctuation within ±5 mm is > 85% (The compliance rates of liquid level fluctuation in the crystallizer with ±5 mm is >85% (see, Hu’s [0042]).
Hu’s passing rate of liquid level fluctuation in the crystallizer with ±5 mm is overlapping with the as recited in the instant claim.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected and produced a steel component from the teachings of Hu that falls within the instantly-claimed ranges, because “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].
It is to be noted, claim recites “and/or” in between the two different limitations, and use of “or” make these limitations as optional and not required by the claim language. Therefore, with a teaching of the passing rate of liquid level fluctuation within ±5 mm, Hu already meets the entire claimed limitation.
However, In addition, Hu also discloses a pass rate of the mold liquid level fluctuation within ±3 mm is > 25% (The compliance rates of liquid level fluctuation in the crystallizer with ±3mm is >25% (see, Hu’s [0042]).
Hu’s passing rate of liquid level fluctuation in the crystallizer with ±3 mm is overlapping with the as recited in the instant claim.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected and produced a steel component from the teachings of Hu that falls within the instantly-claimed ranges, because “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].
Hu further discloses, with the process control described above in this invention significantly improves the quality of the final product (see, Hu’s [0043]).
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Hu’s teachings in view of Lyu to produce a titanium containing ultra-low carbon steel products with a high quality of the final product.
Regarding Claim 11, all the discussions above claim 1 are applicable for claim 11 in addition, Hu discloses during the cold rolling, a cold rolling defect rate caused by Al2O3 are 0% (The cold rolling steel defect of the disclosed Hu’s embodiment, which the steel defects caused by Al2O3 are 0%, see, Hu’s [0051]).
Hu’s defect rate caused by Al2O3 is within the as recited in the instant claim.
Regarding Claim 13, all the discussions above claim 1 and 2 are applicable for claim 13, wherein Hu already discloses in the vacuum refining, before the decarburization treatment, the free oxygen content in the molten steel is adjusted to satisfy a mass ratio O/C=1.96 (after converter blowing, [%C] = 280ppm, [%O] = 550ppm; before vacuum treatment, and the vacuum decarburization started [0050], therefore calculated O/C = 550/280 = 1.96).
Hu’s disclosed mass ratio O/C is within the as recited range of the instant claim.
Claims 5 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Hu Hantao, et.al. [WO2021036974A1] (machine translation) (Hu hereafter) and in view of Yang Kehzhi, et.al. [CN112342333A] (machine translation, original provided in the IDS)) (Yang hereafter) as applied to claim 1, and further in view of I. S. Lysyi et.al. [“DESULFURIZATION OF PIG IRON AND ENSURING SLAG REMOVAL FROM HOT-METAL-CAR LADLES”, All-Union Scientific-Research Institute of Mechanization in Ferrous Metallurgy (VNIImekhchermet). Institute of Ferrous Metallurgy. Translated from Metallurgy, No. 4, pp. 13-16, April, 1984.] (Lysyi, hereafter).
Regarding Claim 5, all the discussions above claim 1 are applicable for claim 5 in addition, Hu discloses the hot metal pretreatment, desulfurization is adopted (hot metal desulfurization, see Hu’s claim 7).
But Hu is silent about the “KR desulfurization is adopted, after which 70% to 80% of a hot metal ladle top slag is removed; and/or a S content in the hot metal after the desulfurization is ≤ 20 ppm”.
Yang teaches in the hot metal pretreatment, KR desulfurization is adopted, and a S content in the hot metal after the desulfurization is ≤ 800 ppm (≤0.003%) (the hot metal pretreatment desulfurization can be performed using the KR method, resulting in an S content ≤ 0.0080% after desulfurization, see Yang’s [0021]).
Yang’s disclosed S content in the hot metal after the desulfurization is overlapping with the as recited in the instant claims.
It is to be noted, claim recites “and/or” in between the two different limitations, and use of “or” make these limitations as optional and not required by the claim language. Therefore, with a teaching of S content in the hot metal after the desulfurization, Yang meet the entire claimed limitation.
But Yang is also silent about the “after desulfurization 70% to 80% of a hot metal ladle top slag is removed.
However, Lysyi teaches analysis and evaluation of the possibility of using various methods of removing slag from hot-metal-car ladles entering the steelmaking after desulfurization, and slag is presently removed from hot-metal-car ladles using scraper-type machines. The ladles are delivered to the mixer department of the converter or open-hearth shop, where the ladle is lifted by overhead crane and transferred to the slag-removal machine. The ladle is tilted with an auxiliary hoist to perform the operation. If the pig has been desulfurized, then the ladle is filled to 70-80% of its capacity and has to be tilted to a 45° angle during the removal operation (see Lysyi’s page 121). Lysyi teaches a scraper hoist is unsatisfactory for several reasons: the complexity of controlling the slag-removal operation with a scraper hoist; the low productivity as 10-15 min required for removing slag from one ladle; incomplete slag removal; the impossibility of removing slag from a ladle tilled at a 45° angle; and the inadequate strength of all of the main components and parts; lack of protection of the work station from high temperatures and spraying metal and slag (see Lysyi’s page 122). Therefore, Lysyi teaches a prototype mixer to remove 70-80% of the slag in 2-3 min, which was installed in the oxygen-converter shop (see Lysyi’s page 124).
Lysyi’s percentage of hot metal ladle top slag removed is within the range as recited in the instant claims.
Lysyi’s process is directed to the desulfurization during production of steel and therefore, analogous to the instant claim and Hu as well as Yang.
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Lysyi’s teachings of adaptation of a prototype mixer to remove 70-80% of the slag after desulfurization to modify Hu’s method in combination with Yang to ensure higher productivity in short time for removing slag from one ladle.
Claims 6 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Hu Hantao, et.al. [WO2021036974A1] (machine translation) (Hu hereafter) and in view of Yang Kehzhi, et.al. [CN112342333A] (machine translation, original provided in the IDS)) (Yang hereafter) as applied to claim 1, and further in view of Hu Hantao, et.al. [CN109402321A] (machine translation, original provided in the IDS) (Hu’321A, hereafter).
Regarding Claim 6, all the discussions above claim 1 are applicable for claim 1 in addition, Hu discloses in the primary converter refining, blowing is stopped, the free oxygen content in the molten steel is ≤ 500 ppm (after converter blowing, [%O] = 550ppm, see Hu’s [0050]), which is within the as recited in the instant claim.
But Hu is silent about a top-bottom combined blowing process is adopted.
Hu is silent about “during tapping, when a tapping amount reaches 1/6 to 1/4, lime is added to a steel ladle in an amount of 1.6 to 3 kg/t steel; and when the tapping amount reaches 4/5 or more, aluminum slag is added to the steel ladle in an amount of 1.0 to 1.4 kg/t steel”
Hu teaches after the tapping is completed, a composition of a steel ladle top slag is adjusted to: FeO+MnO ≤ 7.0wt% (before vacuum treatment, the ladle top slag composition (%FeO) + (%MnO) ≤ 6.50, [0050]), which is within the as recited in the instant claim.
But Hu is silent about a top-bottom combined blowing process is adopted.
Or, Hu is silent about “during tapping, when a tapping amount reaches 1/6 to 1/4, lime is added to a steel ladle in an amount of 1.6 to 3 kg/t steel; and when the tapping amount reaches 4/5 or more, aluminum slag is added to the steel ladle in an amount of 1.0 to 1.4 kg/t steel”.
Or, Hu teaches after the tapping is completed, a composition of a steel ladle top slag is adjusted to: FeO+MnO ≤ 7.0wt% (before vacuum treatment, the ladle top slag composition (%FeO) + (%MnO) ≤ 6.50, [0050]), which is within the as recited in the instant claim. But Hu is silent about the CaO=40 to 50wt%.
Yang teaches a high-efficiency, low-oxygen, ultra-low-carbon steel production method employs a process of hot metal pretreatment desulfurization, converter smelting, argon blowing station, RH refining, and continuous casting. The process, after desulfurization, the scrap steel is charged into the converter has a hot metal and the blowing method is top and bottom combined blowing, with a blowing time from 0 to 16 minutes, the final oxygen content in the converter is 200 to 400 ppm see Yang’s claim 1, 2 [0021]).
Yang’s disclosed free oxygen content is within the as recited in the instant claim.
Yang also teaches after the tapping is completed, a composition of a steel ladle top slag is adjusted to the CaO=50-60% (top slag modifier containing 40%-50% metallic aluminum by mass percentage, with the remainder being CaO (i.e. 50-60%), see Yang’s claim 1, 2 [0021]), and FeO+MnO content is 5.2%–7.8% 7.0wt% (a top slag modifier is added to the argon blowing station to ensure that the FeO+MnO content in the top slag is ≤8% by mass percentage (see Yang’s claim 1, 2 [0021]), and the FeO+MnO content is 5.2%–7.8% by mass percentage see Yang’s claim 5, [0021]).
Yang’s disclosed slag composition overlaps with the as recited in the instant claim.
It is to be noted, claim recites “and/or” in between the two different limitations, and use of “or” make these limitations as optional and not required by the claim language. Therefore, with a teaching of free oxygen content and/or slag composition Yang meet the entire claimed limitation.
But Yang is silent about “during tapping, when a tapping amount reaches 1/6 to 1/4, lime is added; and when the tapping amount reaches 4/5 or more, aluminum slag is added to the steel ladle in an amount of 1.0 to 1.4 kg/t steel”.
However, Hu’321A teaches a production process of ultra-low carbon steel is hot metal pretreatment (desulfurization and dephosphorization of molten iron) – primary converter refining (decarburization in converter) - tapping of steel, modification of top slag in ladle – vacuum refining (RH decarburization, deoxidation and composition fine-tuning) - continuous casting - hot rolling - pickling - cold rolling (see Hu’321A’s [0047]).
Hu’321A then teaches in the primary converter refining, a top-bottom combined blowing process is adopted, wherein when blowing is stopped, the free oxygen content in the molten steel is 450-600 ppm (In converter smelting, top and bottom blowing are adopted, and bottom blowing is maintained to ensure that the molten steel [O] = 450-600ppm and [C] = 0.01-0.05% when blowing stops see Hu’321A’s claim 1, [0019]). Hu’321A then teaches in the smelting of ultra-low carbon steel, the oxygen (free oxygen and combined oxygen) added during converter smelting is the main oxygen source in the entire smelting process. Subsequently, during the tapping process, molten steel and slag containing a large amount of oxygen enter the ladle. In vacuum cyclic refining for decarburization, the oxygen in molten steel forms oxide inclusions during subsequent deoxidation, which is detrimental to the quality of the steel. Therefore, the converter need to maintain good bottom blowing operation (top and bottom re-blowing) to ensure that the molten steel [O] = 450-600ppm when blowing stop (see Hu’321A’s [0019]).
Yang’s disclosed free oxygen content is within the as recited in the instant claim.
In addition, Hu’321A teaches it is guaranteed that the slag thickness of a steel ladle is smaller than or equal to 50 mm in the steel tapping process, 2.0-5.0 kg of lime is added into per ton of steel in the early stage of steel tapping, 0.5-2 kg of an Al quality modification agent is added in per ton of steel at the last stage of steel tapping (see Hu’321A’s abstract). Hu’321A also teaches the tapping process employs a sliding plate slag-blocking operation to ensure that the ladle slag thickness is ≤50mm (without added slag). 2.0-5.0 kg/t steel of lime is added in the early stage of tapping, and 0.5-2 kg/t steel of Al-based modifier is added in the final stage to modify and deoxidize the ladle top slag to maintain the composition of the ladle top slag before vacuum treatment, and oxidizing components (wt.% FeO) + (wt.% MnO) ≤ 8. (see Hu’321A’s [0019]). According to the Example 1, line 24 to 26 of the instant specification of the discloses, “In the early stage of tapping” is described as when the tapping amount reached 1/5, and “the final stage” is described as when the tapping amount reached 9/10”, as Hu’321A teaches similar terminology, “lime is added in the early stage of tapping” and “aluminum slag is added in in the final stage”, therefore, Hu’321A’s lime would have added when the tapping amount reached 1/5, and aluminum slag is added when the tapping amount reached 9/10.
Hu’321A slag tapping amount as well as lime and aluminum slag are within the as recited in the instant claim.
Hu’321A’s process is directed to the production of ultra-low-carbon steel and therefore, analogous to the instant claim and Hu as well as Yang.
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Hu’321A’s teachings of adaptation of top and bottom blowing that requires the converter to maintain good bottom blowing operation to modify Hu’s method in combination with Yang to ensure that the molten steel oxygen content to a controlled amount that is sufficient for decarburization refining, while reducing the oxide inclusions during subsequent deoxidation, to produce high the quality of the steel.
Regarding Claim 15, all the discussions above claim 1 and 6 are applicable for claim 15, but Hu is silent about “during tapping, when a tapping amount reaches 1/6 to 1/4, lime is added to a steel ladle in an amount of 1.6 to 3 kg/t steel; and when the tapping amount reaches 4/5 or more, aluminum slag is added to the steel ladle in an amount of 1.0 to 1.4 kg/t steel”.
But Yang is silent about “during tapping, when a tapping amount reaches 1/6 to 1/4, lime is added; and when the tapping amount reaches 4/5 or more, aluminum slag is added to the steel ladle in an amount of 1.0 to 1.4 kg/t steel”.
However, Hu’321A teaches it is guaranteed that the slag thickness of a steel ladle is smaller than or equal to 50 mm in the steel tapping process, 2.0-5.0 kg of lime is added into per ton of steel in the early stage of steel tapping, 0.5-2 kg of an Al quality modification agent is added in per ton of steel at the last stage of steel tapping (see Hu’321A’s abstract). Hu’321A also teaches the tapping process employs a sliding plate slag-blocking operation to ensure that the ladle slag thickness is ≤50mm (without added slag). 2.0-5.0 kg/t steel of lime is added in the early stage of tapping, and 0.5-2 kg/t steel of Al-based modifier is added in the final stage to modify and deoxidize the ladle top slag to maintain the composition of the ladle top slag before vacuum treatment, and oxidizing components (wt.% FeO) + (wt.% MnO) ≤ 8. (see Hu’321A’s [0019]). According to the Example 1, line 24 to 26 of the instant specification of the discloses, “In the early stage of tapping” is described as when the tapping amount reached 1/5, and “the final stage” is described as when the tapping amount reached 9/10”, as Hu’321A teaches similar terminology, “lime is added in the early stage of tapping” and “aluminum slag is added in in the final stage”, therefore, Hu’321A’s lime is added when the tapping amount reached 1/5, and aluminum slag is added when the tapping amount reached 9/10.
Hu’321A slag tapping amount as well as lime and aluminum slag are within the as recited in the instant claim.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Hu Hantao, et.al. [WO2021036974A1] (machine translation) (Hu hereafter) and in view of Yang Kehzhi, et.al. [CN112342333A] (machine translation, original provided in the IDS) (Yang hereafter), as applied to claim 1, and further in view of Hu Hantao, et.al. [CN109554605A] (machine translation, provided in the IDS) (Hu’605A hereafter)
Regarding Claim 12, all the discussions above claim 1 are applicable for claim 12 in addition, Hu discloses after RH vacuum decarburization is completed, Ti is added, and the amount of Ti added
is the lower limit of the Ti content range of the finished product specification (see Hu’s [0012]) and emphasizes controlling the Ti content (Ti/Al ratio) added for deoxidation to control the final inclusion composition (see Hu’s [0008]).
But Hu is silent about a titanium consumption is less than 0.7 kg/t steel.
Yang teaches slag contain a small amount of Ti oxides, but Yang is also silent about a titanium consumption is less than 0.7 kg/t steel.
However, Hu’605A teaches a method for controlling oxide inclusions in the production of ultra-low carbon steel using a process includes the steps of primary convertor refining, (see Hu’605A’s claim 1 step 1) LD converter smelting), vacuum refining (step 2) the molten steel enters the RH furnace for RH refining, vacuum decarburization is performed in the RH furnace. Al is added to deoxidize the molten steel. Then, refining agent is added at a rate of 0.3-2 kg/t of steel. After the molten steel is circulated purely for 2-10 minutes, alloy is added to adjust the main composition of the molten steel, wherein the main components of the refining agent are as follows: CaO: 50-60wt%, Al2O3: 30-40wt%, MgO: 2-6wt%, SiO2≤3wt%, TiO2<0.08wt%, FeO≤1wt%, H2O≤0.5wt% (see Hu’605A’s claim 1 step 2).
The total amount of TiO2 in the refining agent is calculated from 0.08% of 0.3-2 kg/t of steel, will be 0.024 – 0.16 kg/t of steel, therefore, the amount of Ti=(47.87 / 79.87)×mass of TiO2, or, the amount of Ti ≈ 0.599 × mass of TiO2 and the therefore, amount of Ti ≈ 0.014 to 0.096 kg/t, which is within the as recited in the instant claim.
Hu’605A teaches an example wherein, Al is added to deoxidize the molten steel, immediately afterwards, 1.04 kg/t steel of refining agent is added wherein the composition of TiO2 is less than 0.02 % (see Hu’605A’s [0039] and Table 1 in the original discloser). The total amount of TiO2 in the refining agent is calculated from 0.02% of 1.04 kg/t of steel, will be 0.0208 kg/t of steel, therefore, the amount of Ti ≈ 0.0125 kg/t, which is also within the as recited in the instant claim and the main components of the finished product are: [C] = 0.0014%, [Si] = 0.005%, [Mn] = 0.16%, [Al] = 0.042%, [Ti] = 0.051%, [P] ≤ 0.015%, [S] ≤ 0.01%, [N] ≤ 0.003% (see Hu’605A’s [0039]). Hu’605A’s steel composition is within the claimed composition as well as Hu’s steel.
Hu’605A further teaches TiO2 has a very high melting point and exists as a solid phase in the slag formed by refining agents, resulting in poor slag fluidity which should be restricted (see Hu’605A’s [0023]) and controlling oxide inclusions in the production of ultra-low carbon steel. Hu’605A’s process thereby reduced the number of inclusions in the billet, improves the yield of liquid level fluctuations in the continuous casting crystallizer, reducing the incidence of inclusion-related defects during rolling, and lowering the oxygen content of the finished product and demonstrating a significant cleaning effect on the molten steel, and the cold rolling blockage rate is reduced from 3.05% to 0.99%, showing significant improvement (see Hu’605A’s [0010]).
Hu’605A’s process is directed to the production of ultra-low-carbon steel and therefore, analogous to the instant claim and Hu as well as Yang.
Therefore, it would have been further obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Hu’605A’s teachings of deoxidizing with Al and limiting Ti content in the refining agent to modify Hu’s deoxidation and refining process in combination with Yang to ensure the final composition and lowering the oxygen content of the finished product while demonstrating a significant cleaning effect on the molten steel reducing inclusion-related defects during rolling.
Response to Arguments
Applicant's arguments filed 06/26/2026 have been fully considered but they are not persuasive. Because,
In response to applicant's argument about the previous 35 USC § 112(b) rejections of the claims 5-6, and 14-15, the amendments did not find support in the specification, as shown in the section of the 35 USC § 112 (a) rejections of these claims, for claim 5 and 14, both of these claim recites a new limitation “based on a thickness of the hot metal ladle top slag”, however, process on the page 4 of the instant specification of the disclosure, describes “KR desulfurization is adopted, after which 70% to 80%, such as 3/4, of the top slag in the hot metal ladle is removed”, wherein there is no description about “the top slag in the hot metal ladle is removed based on a thickness of the hot metal ladle top slag” and in case of claim 6 and 15, both of these claim recites a new limitation “of a total molten steel volume”, however, process on the page 5 of the instant specification of the disclosure, describes “during the tapping process, when the tapping amount reaches 1/6 to 1/4, such as 1/5, lime is added to the steel ladle in an amount of 1.6 to 3 kg/t steel; and when the tapping amount reaches 4/5 or more, such as 9/10,”, wherein there is no description about “the tapping amount is a percentage of a total molten steel volume”, therefore, the previous 35 USC § 112(b) rejections have been maintained.
With respect to Applicant’s argument regarding Hu, that, “now amended method, Al is directly added for deoxidation upon completion of decarburization, whereas process disclosed in HU'974A1 adopts Ti addition prior to Al for deoxidation after decarburization”, does not seem persuasive, because,
it is noted that the features upon which applicant relies (i.e., Al is directly added for deoxidation upon completion of decarburization without any Ti addition) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993), in this case, claim does not recite “Al is directly added for deoxidation upon completion of decarburization without any Ti addition”, claim recites after decarburization Al is added and Hu teaches after decarburization is completed, then Al is added (see Hu’s claim 1 [0050])
in addition, claim recites the transitional term "comprising", which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. See, e.g., Mars Inc. v. H.J. Heinz Co., 377 F.3d 1369, 1376, 71 USPQ2d 1837, 1843 (Fed. Cir. 2004) ("[L]ike the term ‘comprising,’ the terms ‘containing’ and ‘mixture’ are open-ended."). Invitrogen Corp. v. Biocrest Manufacturing, L.P., 327 F.3d 1364, 1368, 66 USPQ2d 1631, 1634 (Fed. Cir. 2003) ("The transition ‘comprising’ in a method claim indicates that the claim is open-ended and allows for additional steps."); Genentech, Inc. v. Chiron Corp., 112 F.3d 495, 501, 42 USPQ2d 1608, 1613 (Fed. Cir. 1997) [see MPEP 211.03], therefore, in this case, according to the claim language, claim does not exclude “Ti addition prior to Al for deoxidation after decarburization”;
With respect to Applicant’s argument regarding Hu, that, “instant controlling the oxygen content of the molten steel at the end of decarburization and ensuring the purity of the added rare earth component, especially the oxygen content, can effectively suppress the impact of Ti in the molten steel on the surface wettability of Al2O3 in the molten steel, and in turn alleviate nozzle blocking during the continuous casting process, thereby ensuring a stable liquid level in the mold and a smooth working of continuous casting process”, does not seem persuasive, because, according to the page 7 of the instant specification of the discloser describes especially the oxygen content, can effectively suppress the impact of Ti in the molten steel on the surface wettability of Al2O3 in the molten steel, i.e. easy nozzle blocking problem caused by Ti addition is solved by controlling oxygen content, i.e. does not exclude “Ti addition” and dependent claim 12 requires a Ti consumption of 0.7kg/t, i.e. Ti addition is not excluded. In addition, Hu teaches the nozzle clogging issues caused by Ti addition as well as Hu also teaches a solution to suppress the problem, is that the total amount of inclusions in steel must be reduced to an extremely low level and large particles must be eliminated from the steel. From the perspective of controlling inclusion characteristics, the hazards of inclusions remaining in steel must be reduced as much as possible (see Hu’s [0004]) and for titanium-containing ultra-low carbon steel, it is necessary to control the characteristics of oxide inclusions in the steel and ensure the stability of the casting process during smelting, so as to reduce the harm of Al deoxidation products to cold-rolled steel (see Hu’s [0006]) and emphasizes that the process effect of its invention is due to controlling the Ti content (Ti/Al ratio) added for deoxidation (see Hu’s [0008]) and controlling the oxygen content (see Hu’s [0012], [0021]). However, Hu is only silent about “after decarburization is completed, a free oxygen content in molten steel is 100 to 350 ppm”, but the secondary prior art Yang meets the deficiency as Yang teaches the oxygen content in the steel at the decarburization endpoint is maintained ≤300 ppm; after decarburization, oxygen is determined, and aluminum particles are added for deoxidation based on the oxygen determination result; after the aluminum particles are added, pure circulation is performed for 2-4 minutes, followed by alloying, (see Yang’s claim 7, [0014]) and the oxygen content in the decarburization endpoint steel is controlled at 138–276 ppm (see Yang’s claim 8, [0015]). Yang’s disclosed free oxygen content after the decarburization is within the as recited in the instant claims. Yang teaches controlling of oxygen content to provide a high-efficiency, low-oxygen, ultra-low-carbon steel production method to simplify converter and RH treatment tasks, and improve production efficiency and steel cleanliness (see Yang’s [0007]) and low oxygen level control throughout the smelting process effectively reduces the accumulation of ultra-low carbon steel during casting, improves the castability of the molten steel, and reduces the incidence of defects in the steel zone of cold-rolled products (see Yang’s [00019]) and Yang’s oxygen content (see Yang’s [00019]). Therefore, Hu in view of Yang teaches all the limitations of claim 1.
With respect to Applicant’s argument regarding Lyu have been considered but are moot because the new ground of rejection does not rely on Lyu applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Therefore, a 35 USC § 103 rejection of the claim 1 and other dependent claims have been made Hu over Yang, due to the amendments (please check the section of the 35U.S.C. 103 rejection associated with this office action for further details).
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 extension fee 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 date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NAZMUN NAHAR SHAMS whose telephone number is (571)272-5421. The examiner can normally be reached M-F 11:00 AM-7:00PM (EST).
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/NAZMUN NAHAR SHAMS/Examiner, Art Unit 1738
/SALLY A MERKLING/SPE, Art Unit 1738
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