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 .
Response to Arguments
Applicant's arguments filed 4/30/2026 have been fully considered but they are not persuasive. Applicant traverses the 35 U.S.C. 103 rejection of claim 1 over Kim et al. (US 2021/0187583) on the following grounds: The Office improperly maps the second layer of the steel sheet in Kim to the claimed “Al-Fe intermetallic compound layer”.
This argument is not persuasive. The claimed Al-Fe intermetallic compound layer comprises an Al-rich phase having an Al concentration of 40% or more, and an Fe-rich phase having an Al concentration of less than 40%. Kim teaches a second layer that includes, as Applicant concedes, an intermetallic compound portion and intermetallic compound phases. The intermetallic compound phases of the second layer in Kim comprises intermetallic compound phases such as FeAl3 or Fe2Al5 (¶ 7), which comprises 59% and 55% Al, respectively. This corresponds to the claimed Al-rich phase. The intermetallic compound portion, on the other hand, comprises 62%-67% Fe and 30%-34% Al (¶ 9). This corresponds to the claimed Fe-rich phase.
Applicant’s argument regarding the discontinuity of the intermetallic compound portion is not persuasive. Whether or not it is discontinuous has no bearing on the prior art rejection. Kim discloses the second layer contains an intermetallic compound portion which has 62%-67% Fe (¶ 9), which corresponds to the claimed Fe-rich phase. Kim also discloses the second layer contains FeAl3 and Fe2Al5 phases (¶ 7), which correspond to the claimed Al-rich phase. Nothing in Kim supports assuming that the intermetallic compound portion contains the Al-rich phases, as this would clearly lead to a composition mismatch since FeAl3 and Fe2Al5 contain 59% and 55% Al, respectively, and the intermetallic compound portion contains only 30%-34% Al (see ¶ 9). The rejection over Kim is therefore maintained.
Applicant traverses the 35 U.S.C. 103 rejection of claim 3 over Sung et al. (US 2021/0402740) on the following grounds: The claimed Si-rich phase area fraction is obtained by (A) decreasing Si content in the coating bath, and (B) decreasing Si content in the outermost surface layer of the steel by one of three process steps. Applicant appears to concede that Sung teaches (B), but alleges that (A) is not disclosed in Sung.
This argument is not persuasive. The instant specification states that the Si content in the plating bath must be 0.5%-7.0% to achieve the claimed Si-rich phase area fraction (see Spec., [0114]-[0115]). This is requirement (A). Sung teaches the plating bath contains 4%-12% Si (¶ 76), and the exemplary plating bath contains 7% Si (¶ 85). The steel sheet of Sung is therefore made by a process that is substantially identical to that claimed, and one of ordinary skill in the art would expect the prior art steel sheet to exhibit the claimed Si-rich phase area fraction, absent objective evidence to the contrary. See MPEP 2112. Applicant’s arguments are not persuasive and the rejection over Sung is maintained.
Claim Rejections - 35 USC § 103
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.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Kim et al. (US 2021/0187583).
Regarding claim 1, Kim discloses a hot stamping component (¶ 6). The component comprises a base steel plate and a plated layer on the steel plate (¶ 6). The plated layer includes a first layer (corresponding to the diffusion layer) and a second layer (corresponding to the Al-Fe intermetallic layer) in this order from the steel plate (¶ 6). Kim states the plated layer is formed after hot stamping (see ¶ 52). Kim teaches the second layer comprises intermetallic compound phases such as FeAl3 or Fe2Al5 (¶ 7) which comprises 59% and 55% Al, respectively. The second layer also comprises an “intermetallic compound portion” which comprises 62%-67% Fe and 30%-34% Al (¶ 9). This intermetallic compound portion has a 1 μm – 5 μm unit length and corresponds to the claimed length of the Fe-rich phase. Kim teaches the thickness of the plated layer is 10 μm – 50 μm (¶ 50), with the thickness of the second layer being 1.6-3.6 times the thickness of the first layer (¶ 52). The thickness of the second layer is therefore about 6 μm – 39 μm. The prior art ranges either overlap or lie within the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Kim et al. (US 2021/0187583), as applied to claim 1, further in view of Oh et al. (US 2022/0049338).
Regarding claim 2, the limitations of claim 1 have been addressed above. Kim does not teach a diffusible hydrogen content in the steel is 0.30 mass ppm or less. Oh teaches a hot press forming member having a content of diffusible hydrogen of 0.1 ppm or less (¶ 16). It would have been obvious at the effective time of filing of the claimed invention for one of ordinary skill in the art to modify the diffusible hydrogen content of the steel of Kim according to the teachings of Oh because a lower diffusible hydrogen content is associated with increased hydrogen embrittlement resistance and improved weldability (¶¶ 92, 94).
Claims 3-4, 6-7, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Sung et al. (US 2021/0402740).
Regarding claim 3, Sung teaches a steel sheet for hot pressing (¶ 8). The steel sheet includes a plating layer having a diffusion layer (corresponding to the claimed interfacial layer) and a surface layer (corresponding to the metal layer) (¶ 8). The surface layer contains at least 80% wt aluminum (¶ 48) and the diffusion layer contains 0.1%-40% wt silicon (¶ 48). Accordingly, there must be Si-rich phases containing at least 4% mass silicon, absent objective evidence to the contrary. See MPEP 2112.
Sung does not teach or suggest a cross-section area fraction of Si-rich phases in the diffusion layer is 5%-30%. However, the instant specification obtains the claimed area fraction of Si-rich phases by setting the Si content in the coating bath to 0.5%-7.0% (¶ 131), and either coiling after hot rolling at 600°C -800°C (¶ 142), recrystallization annealing at a dew point of 0°C-20°C (¶ 145), or forming a Fe pre-coat layer (¶ 146). Sung teaches a plating bath containing 4%-12% Si (¶ 76), with an exemplary 7% (¶ 85), and coiling after hot rolling at a temperature of 550°C -800°C (¶ 71). This is substantially similar to the claimed process. Accordingly, one of ordinary skill in the art would expect the claimed cross-section area fraction of Si-rich phases in the prior art steel, absent objective evidence to the contrary. See MPEP 2112.
Regarding claim 4, Sung teaches the surface layer is at least 80% wt Al (¶ 48). Therefore, the surface layer must contain at most 20% Si and Fe, absent objective evidence to the contrary. This overlaps the claimed ranges, creating a prima facie case of obviousness. See MPEP 2144.05 I.
Regarding claims 6-7, since Sung teaches a steel sheet for hot pressing (¶ 8), a method of hot pressing the steel sheet to obtain a hot-pressed member is implicitly taught.
Regarding claim 9, Sung does not expressly teach Si-rich phases contain Si, Fe, Mn, and Al. However, the instant specification states Si reacts with Al in the bath, and Fe and Mn in the base steel sheet (see Spec., ¶ 152). In Sung, the plating bath contains Al (¶ 17), and the base steel sheet contains Fe and Mn (¶ 33). Si is inherently present in an Si phase. Accordingly, one of ordinary skill in the art would expect the Si-rich phases of Sung to contain Si, Fe, Mn, and Al, absent objective evidence to the contrary. See MPEP 2112.
Claims 5 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Sung et al. (US 2021/0402740), as applied to claim 4, further in view of Oh et al. (US 2022/0049338).
Regarding claim 5, the limitations of claim 4 have been addressed above. Sung teaches including Mg in the plating bath (¶ 77), but does not teach or suggest the amount to include. Oh teaches including up to 1.1% wt Mg (¶ 40) for plating aluminum alloy on steel sheet for hot pressing (¶ 39) in order to improve the corrosion resistance of the steel (¶ 40). It would have been obvious at the effective time of filing for one of ordinary skill in the art to include Mg as taught by Oh in the metal layer of Sung to improve corrosion resistance.
Regarding claim 8, since Sung teaches a steel sheet for hot pressing (¶ 8), a method of hot pressing the steel sheet to obtain a hot pressed member is implicitly taught.
Conclusion
THIS ACTION IS MADE FINAL. 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 XIAOBEI WANG whose telephone number is (571)270-5705. The examiner can normally be reached M-F 8AM-5PM EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Humera Sheikh can be reached at 571-272-0604. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/XIAOBEI WANG/Primary Examiner, Art Unit 1784
Prosecution Insights