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 .
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.
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.
Claims 1-2 are rejected under 35 U.S.C. 103 as being unpatentable over Noguchi (US 2022/0145438 A1, claiming foreign priority date of Aug. 19, 2019).
Regarding claims 1 and 2, Noguchi teaches a duplex stainless steel with a composition range as shown in Table 1 below (Clm. 1). The claimed composition is also listed for comparison.
Table 1
Ref.
Noguchi
Applicant
Element
Composition (wt%)
C
0-0.03
0-0.030
Si
0.2-1
0.20-1.00
Mn
0.50-7.00
0.50-7.00
P
0-0.040
0-0.040
S
0-0.010
0-0.020
Ni
4.2-9.00
4.2-9.00
Al
0-0.100
0-0.100
N
0.150-0.350
0.150-0.350
Cr
20.00-28.00
20.00-30.00
Mo
0.50-2.00
0.50-2.00
Cu
1.90-4.00
1.50-4.00
V
0.01-1.50
0.01-1.50
Ca
0.0001-0.0200
0.0001-0.020
Mg
0.0001-0.0200
0.0001-0.020
Fe
Bal
Bal
Noguchi’s ranges either overlap with the claimed ranges or are within the claimed ranges. Additionally, Noguchi exemplifies steels with compositions that are within the claimed composition ranges (Table 1). Using Noguchi’s minimum and maximum composition ranges, the calculated values of formula (1) are between 24.05-40.20, which reads on the claimed formula condition of greater than or equal to 30. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Noguchi also teaches that their steels have microstructures consisting of 35.0-50 wt% ferrite with a balance of austenite (Clm. 1), which read on the claimed ferrite and austenite ratios. The steels also have a yield strength of 550 MPa or more (Clm. 1), which reads on the claimed yield strength range of 586 MPa or more. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See MPEP 2144.05(1).
Noguchi is silent on the number density of Cu precipitates in the austenite. However, it is noted that the steel production method taught by Noguchi has significant overlap with the applicant’s disclosed steel production method. Particularly, Noguchi’s method comprises the following steps:
A hot working step [0191-192], which is shared with the applicant.
A solution heat treatment step [0194-198], wherein the hot worked steel is treated at a temperature of 900-1200OC for 5-180 minutes. Noguchi’s temperatures and times read on the applicant’s disclosed temperature of 960-1100OC and time of 5-180 minutes.
A quenching step [0198], which reads on the applicant’s disclosed rapid cooling step.
It is noted that Noguchi is silent on a maintaining step after the solution heat treatment step (i.e. keeping the steel at a temperature between 900-950 for 20-180 s, as per the specification). However, given Noguchi’s taught temperature and time ranges for their disclosed solution heat treatment step, the disclosed maintaining step is intrinsically incorporated into Noguchi’s solution heat treatment step.
In all, Noguchi’s steel composition and production method have significant overlap the applicant’s steel composition and production method. The overlap is significant enough that a steel produced by Noguchi’s method will inherently have a number density of Cu precipitates in the austenite phase having a major axis of 50 nm or less between 150 and 1500 /m3. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established (See MPEP 2112.01).
Contact Information
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAVIER FLORES whose telephone number is 571-272-9130. The examiner can normally be reached Mon-Fri 7:30AM-5:00PM.
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, KEITH WALKER can be reached at 571-272-3458. 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.
/J.F./Examiner, Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735
Prosecution Insights