Patents by Inventor Dong-Chul Chae

Dong-Chul Chae has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11299799
    Abstract: An austenitic stainless steel product having excellent surface characteristics and a manufacturing method therefor are disclosed. The disclosed austenitic stainless steel product comprises an austenitic stainless steel comprising, by weight percent, 0.005 to 0.15% of C, 0.1 to 1.0% of Si, 0.1 to 2.0% of Mn, 6.0 to 8.0% of Ni, 16 to 18% of Cr, 0.1 to 4.0% of Cu, 0.005 to 0.2% of N, 0.01 to 0.2% of Mo, and the remainder comprising iron (Fe) and other unavoidable impurities, and a Ni surface negative segregation thereof defined by the following formula (1) is 0.6 to 0.9 and the martensite fraction thereof is 10 to 30%. (CNi-Min)/(CNi-Ave)??formula (1) Here, CNi-min is the minimum concentration of Ni on the surface and CNi-Ave is the average concentration of Ni on the surface.
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: April 12, 2022
    Assignee: POSCO
    Inventors: Hyung Gu Kang, Jae-Hong Shim, Gyu Jin Jo, Dong Chul Chae
  • Publication number: 20200190643
    Abstract: An austenitic stainless steel product having excellent surface characteristics and a manufacturing method therefor are disclosed. The disclosed austenitic stainless steel product comprises an austenitic stainless steel comprising, by weight percent, 0.005 to 0.15% of C, 0.1 to 1.0% of Si, 0.1 to 2.0% of Mn, 6.0 to 8.0% of Ni, 16 to 18% of Cr, 0.1 to 4.0% of Cu, 0.005 to 0.2% of N, 0.01 to 0.2% of Mo, and the remainder comprising iron (Fe) and other unavoidable impurities, and a Ni surface negative segregation thereof defined by the following formula (1) is 0.6 to 0.9 and the martensite fraction thereof is 10 to 30%. (CNi-Min)/(CNi-Ave)??formula (1) Here, CNi-min is the minimum concentration of Ni on the surface and CNi-Ave is the average concentration of Ni on the surface.
    Type: Application
    Filed: December 4, 2017
    Publication date: June 18, 2020
    Inventors: Hyung Gu Kang, Jae-Hong Shim, Gyu Jin Jo, Dong Chul Chae
  • Publication number: 20200095656
    Abstract: The present invention discloses a gold-colored steel sheet capable of expressing color without peeling of a modified layer and the gold-colored steel sheet capable of forming a color-modified layer through a conventional annealing process without expensive facilities. A method of manufacturing the gold-colored steel sheet according to an embodiment of the present invention can form a TiN modified layer on a surface of a steel sheet comprising 0.3 to 1.5 wt % of titanium (Ti) by an annealing treatment in a nitrogen (N2) atmosphere at 900 to 1,200° C. for 30 to 300 seconds.
    Type: Application
    Filed: May 15, 2017
    Publication date: March 26, 2020
    Inventors: Jung-Hyun Kong, Sang Seok Kim, Min Nam Park, Dong Chul Chae
  • Publication number: 20190177814
    Abstract: Provided is a lean duplex stainless steel having excellent bending processability. The lean duplex stainless steel includes, in percent (%) by weight of the entire composition, 0.01 to 0.06% of carbon (C), 0.2 to 1.0% of silicon (Si), 3.5 to 6.5% of manganese (Mn), 18.5 to 22.5% of chromium (Cr), 0.05 to 0.25% of nitrogen (N), and the remainder of iron (Fe) and other inevitable impurities, wherein a sum of amounts of Cr and Mn is from 26.0 to 28.5% and a Cr/Mn ratio is from 3.4 to 4.1.
    Type: Application
    Filed: July 31, 2017
    Publication date: June 13, 2019
    Inventors: Dong Chul Chae, Gyu Jin Jo, Bong-Wn Kim
  • Publication number: 20190010588
    Abstract: Disclosed is an austenitic stainless steel with increased workability. The austenitic stainless steel includes, based on % by weight, silicon (Si): 0.1 to 0.65%, manganese (Mn): 0.2 to 3.0%, nickel (Ni): 6.5 to 10.0%, chromium (Cr): 16.5 to 20.0%, copper (Cu): 6.0% or less (excluding 0), the sum of carbon (C) and nitrogen (N): 0.08% or less (excluding 0), and the remainder being Fe and unavoidable impurities, wherein the austenitic stainless steel has a work hardening rate of 1500 MPa or less within a true strain range of 0.15 to 0.4. Therefore, when a sink bowl and the like are processed using the austenitic stainless steel, the true strain and work hardening rate of which are controlled, the occurrence of delayed fracture in a molded corner thereof, which has been subjected to a large amount of processing, can be prevented.
    Type: Application
    Filed: December 21, 2016
    Publication date: January 10, 2019
    Inventors: Hyung Gu KANG, Jeom Yong CHOI, Dong Chul CHAE, Jee Hyun YU, Gyu Jin JO
  • Publication number: 20170349985
    Abstract: Austenitic stainless steels excellent in flexibility are provided. The austenitic stainless steel excellent in flexibility includes, by weight percent, 0.1 to 0.65% of Si, 1.0 to 3.0% of Mn, 6.5 to 10.0% of Ni, 16.5 to 18.5% of Cr, 6.0% or less of Cu (excluding 0), 0.13% or less of (C+N) (excluding 0), and the remainder including Fe and unavoidable impurities, wherein the work hardening formula H1 defined by the following formula is 300 or less. H1=?459+79.8Si?10.2Mn?8.16Ni+48.0Cr?13.2Cu+623(C+N).
    Type: Application
    Filed: December 1, 2015
    Publication date: December 7, 2017
    Inventors: Hyung Gu KANG, Gyu Jin JO, Dong Chul CHAE, Jae Hwa LEE
  • Publication number: 20170327916
    Abstract: A high-hardness martensitic stainless steel with excellent antibacterial property and a preparation method therefor are disclosed. The high-hardness martensitic stainless steel with excellent antibacterial property comprises: 0.45-0.65 wt % of C; 0.02-0.06 wt % of N; 0.1-0.6 wt % of Si; 0.3-1.0 wt % of Mn; 0.1-0.4 wt % of Ni; 13-14.5 wt % of Cr; 0.4-0.6 wt % of Mo; 0.8-1.2 wt % of W; 1.5-2.0 wt % of Cu; and the balance of Fe and inevitable impurities. According to the present disclosure, there is an advantage enabling the preparation of the martensitic stainless steel for knives, the martensitic stainless steel having high hardness, high corrosion resistance and excellent antibacterial property, by uniformly distributing fine chromium carbide and e-Cu precipitates in the microstructure of a batch annealed material of a high-carbon martensitic stainless steel containing Cu. In addition, there is an advantage of causing no rust formation on a material after an antibacterial evaluation.
    Type: Application
    Filed: November 20, 2015
    Publication date: November 16, 2017
    Inventors: Jae Hwa LEE, Gyu Jin JO, Dong Chul CHAE
  • Patent number: 9790565
    Abstract: A hot-rolled stainless steel sheet having excellent hardness and low-temperature impact properties, in which a ferrite is formed with martensite as a matrix structure, is manufactured by a steel manufacturing process, a continuous casting process, and a hot-rolling process. The hot-rolled stainless steel sheet comprises C, N, Si, Mn, Cr, Ni, Ti, Nb, Mo, and the remainder being Fe and other inevitable impurities, wherein C is 0.01 to 0.03 wt %, Cr is 11 to 14 wt %, Ti is 0.1 to 0.2 wt %, and Nb is 0.1 to 0.2 wt %. The ferrite stability (FS) expressed by the following [formula 1] is 5 to 50, and a ferrite is formed with martensite as a matrix structure. [Formula 1] 4 FS=?215?619C?16.6Mn+23.7Cr?36.8Ni+42.2Mo+96.2Ti+67Nb?237N+17.2Si, wherein the numerical value of each component described in [Formula 1] denotes the content (wt %) of each component.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: October 17, 2017
    Assignee: POSCO
    Inventors: Dong Chul Chae, Gyu Jin Jo, Jae Hwa Lee, Kwang Yuk Kim
  • Patent number: 9731345
    Abstract: Provided is a martensitic stainless steel having excellent productivity and high corrosion resistance, which comprises, as percentages by weight, 0.45 to 0.60% carbon, 0.02 to 0.08% nitrogen, 0.2 to 0.4% silicon, 0.3 to 0.6% manganese, 12 to 15% chromium, one or more kinds of 0.1 to 1.5% molybdenum or 0.1 to 1.5% tungsten and Fe and other unavoidable impurities as remnants.
    Type: Grant
    Filed: December 26, 2011
    Date of Patent: August 15, 2017
    Assignee: POSCO
    Inventors: Ki-Hoon Jo, Dong-Chul Chae, Won-Qeun Son, Bong-Wn Kim
  • Publication number: 20150315686
    Abstract: A hot-rolled stainless steel sheet having excellent hardness and low-temperature impact properties, in which a ferrite is formed with martensite as a matrix structure, is manufactured by a steel manufacturing process, a continuous casting process, and a hot-rolling process. The hot-rolled stainless steel sheet comprises C, N, Si, Mn, Cr, Ni, Ti, Nb, Mo, and the remainder being Fe and other inevitable impurities, wherein C is 0.01 to 0.03 wt %, Cr is 11 to 14 wt %, Ti is 0.1 to 0.2 wt %, and Nb is 0.1 to 0.2 wt %. The ferrite stability (FS) expressed by the following [formula 1] is 5 to 50, and a ferrite is formed with martensite as a matrix structure. [Formula 1] 4 FS=?215?619C?16.6Mn+23.7Cr?36.8Ni+42.2Mo+96.2Ti+67Nb?237N+17.2Si, wherein the numerical value of each component described in [Formula 1] denotes the content (wt %) of each component.
    Type: Application
    Filed: December 27, 2012
    Publication date: November 5, 2015
    Applicant: POSCO
    Inventors: Dong Chul CHAE, Gyu Jin JO, Jae Hwa LEE, Kwang Yuk KIM
  • Publication number: 20130309126
    Abstract: Provided is a martensitic stainless steel having excellent productivity and high corrosion resistance, which comprises, as percentages by weight, 0.45 to 0.60% carbon, 0.02 to 0.08% nitrogen, 0.2 to 0.4% silicon, 0.3 to 0.6% manganese, 12 to 15% chrome, one or more kinds of 0.1 to 1.5% molybdenum or 0.1 to 1.5% tungsten and Fe and other unavoidable impurities as remnants.
    Type: Application
    Filed: December 26, 2011
    Publication date: November 21, 2013
    Applicant: POSCO
    Inventors: Ki-Hoon Jo, Dong-Chul Chae, Won-Qeun Son, Bong-Wn Kim
  • Publication number: 20130122320
    Abstract: A martensitic stainless steel for use in tableware, knives, scissors and the like, containing in % by weight, 0.10 to 0.50% carbon and 11 to 16% chromium, and a production method therefore.
    Type: Application
    Filed: December 20, 2010
    Publication date: May 16, 2013
    Applicant: POSCO
    Inventors: Dong-Chul Chae, Jong-Heon Seok, Joon-In Kwon, Byoung-Jun Song, Ki-Hoon Jo, Mi-Nam Park
  • Publication number: 20120321501
    Abstract: The present invention relates to a production method for high-carbon martensitic stainless steel as used in razorblades, knives and the like, which contains, as percentages by weight, 0.40 to 0.80% carbon and 11 to 16% chromium as main components. Provided is a production method for high-carbon martensitic stainless steel in a strip-casting device, wherein a stainless-steel thin sheet is cast by supplying a stainless molten steel containing, as percentages by weight, 0.40 to 0.80% carbon and from 11 to 16% chromium to a molten steel pool from a tundish via a nozzle, and the cast stainless-steel thin sheet is made into a hot-rolled annealed strip using in-line rollers to a rolling reduction of 5 to 40% immediately just after the casting so that the size of primary carbides within the microstructure of the hot-rolled annealed strip is 10 ?m or less, and also provided is martensitic stainless steel produced by means of the production method.
    Type: Application
    Filed: December 20, 2010
    Publication date: December 20, 2012
    Applicant: POSCO
    Inventors: Dong-Chul Chae, Bo-Sung Seo, Seung-Bae Ahn, Seong-In Jeong, Jae-Hwa Lee, Gyu-Jin Jo