Patents by Inventor Un-Hae LEE

Un-Hae LEE 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: 10961610
    Abstract: Provided according to one embodiment of the present invention are a non-magnetic steel material and a method for manufacturing the same. The steel material comprises 15-27 wt % of manganese, 0.1-1.1 wt % of carbon, 0.05-0.50 wt % of silicon, 0.03 wt % or less (0% exclusive) of phosphorus, 0.01 wt % or less (0% exclusive) of sulfur, 0.050 wt % or less (0% exclusive) of aluminum, 5 wt % or less (0% inclusive) of chromium, 0.01 wt % or less (0% inclusive) of boron, 0.1 wt % or less (0% exclusive) of nitrogen, and a balance amount of Fe and inevitable impurities, has an index of sensitivity of 3.4 or less, the index of sensitivity being represented by the following relational expression (1): [Relational expression 1]—0.451+34.131*P+111.152*Al?799.483*B+0.526*Cr?3.4 (wherein [P], [Al], [B] and [Cr] each mean a wt % of corresponding elements), and contains a microstructure with austenite at an area fraction of 95% or greater therein.
    Type: Grant
    Filed: December 23, 2016
    Date of Patent: March 30, 2021
    Assignee: POSCO
    Inventors: Un-Hae Lee, Sung-Kyu Kim, Soon-Gi Lee, Yong-Jin Kim, Hong-Yeol Oh
  • Publication number: 20200347486
    Abstract: A high-strength austenite-based high-manganese steel material and a manufacturing method for the same, the steel material comprising: manganese (Mn): 20 to 23 wt %, carbon (C): 0.3 to 0.5 wt %, silicon (Si): 0.05 to 0.50 wt %, phosphorus (P): 0.03 wt % or less, sulfur (S): 0.005 wt % or less, aluminum (Al): 0.050 wt % or less, chromium (Cr): 2.5 wt % or less, boron (B): 0.0005 to 0.01 wt %, nitrogen (N): 0.03 wt % or less, and a balance of iron (Fe) and other inevitable impurities, wherein stacked defect energy (SFE) represented by the following relationship 1 is 3.05 mJ/m2 or more, and a microstructure comprises 95 area % or more (including 100 area %) of austenite, and comprises 6 area % or more of strain grain boundaries in an austenite recrystallized grain, is provided. SFE (mJ/m2)=?24.2+0.950*Mn+39.0*C?2.53*Si?5.50*Al?0.765*Cr??[Relationship 1] where Mn, C, Cr, Si, and Al denote weight percent of respective components.
    Type: Application
    Filed: December 20, 2018
    Publication date: November 5, 2020
    Inventors: Un-Hae LEE, Tae-Kyo HAN, Sang-Deok KANG, Sung-Kyu KIM, Yong-Jin KIM
  • Publication number: 20200263268
    Abstract: The present invention relates to a high manganese steel for low temperature applications and a method for manufacturing the same. The high manganese steel contains 0.3 wt % to 0.8 wt % of C, 18 wt % to 26 wt % of Mn, 0.01 wt % to 1 wt % of Si, 0.01 wt % to 0.5 wt % of Al, 0.1 wt % or less of Ti (excluding 0%), 1 wt % to 4.5 wt % of Cr, 0.1 wt % to 0.9 wt % of Cu, 0.03 wt % or less of S (excluding 0%), 0.3 wt % or less of P (excluding 0%), 0.001 wt % to 0.03 wt % of N, 0.004 wt % or less of B (excluding 0%), and a remainder of Fe and other inevitable impurities, wherein a microstructure comprises an austenite single phase structure, and an average grain size of the austenite is 50 ?m or less.
    Type: Application
    Filed: October 11, 2018
    Publication date: August 20, 2020
    Inventors: Yu-Mi Ha, Young-Deok Jung, Sang-Deok Kang, Un-Hae Lee, Yong-Jin Kim, Sung-Kyu Kim, Young-Ju Kim
  • Publication number: 20200087751
    Abstract: The present disclosure relates to an austenitic steel having excellent surface characteristic, and a method of manufacturing the same. Provided are an austenitic steel having excellent surface characteristic, and a method for producing the same, the austenitic steel according to an aspect of the present disclosure comprising, by weight, carbon (C): 0.6% to 1.3%, manganese (Mn): 14% to 22%, copper (Cu): 5% or less (excluding 0%), chromium (Cr): 5% or less (excluding 0%), silicon (Si): 1.0% or less (excluding 0%), aluminum (Al): 0.5% or less (excluding 0%), phosphorus (P): 0.1% or less (including 0%), sulfur (S): 0.02% or less (including 0%), a remainder of iron (Fe), and inevitable impurities, wherein a microstructure of the austenitic steel comprises, by area, 5% or less of carbide and a remaining austenite structure, and a surface defect size of the austenitic steel is 0.3 mm or less.
    Type: Application
    Filed: December 21, 2017
    Publication date: March 19, 2020
    Inventors: Yong-Jin KIM, Hong-Yeol OH, Sang-Deok KANG, Un-Hae LEE, Yu-Mi HA
  • Publication number: 20190010571
    Abstract: The present invention relates to a high hardness wear-resistant steel with excellent toughness and cutting crack resistance, and a method for manufacturing the same. A high hardness wear-resistant steel according to one aspect of the present invention has a composition containing, by weight ratio, 2.1 to 4.0% of manganese (Mn), 0.15 to 0.2% of carbon (C), 0.02 to 0.5% of silicon (Si), 0.2 to 0.7% of chromium (Cr), a remainder of iron (Fe) and other unavoidable impurities, has a microstructure in which prior austenite grain size is 25 ?m or less and martensite is included as a main phase, and has excellent toughness and cutting crack resistance which satisfies a condition in which Ac3-Ac1 is 100° C. or lower.
    Type: Application
    Filed: November 22, 2016
    Publication date: January 10, 2019
    Inventors: Il-Cheol YI, Yong-Jin KIM, Sung-Kyu KIM, Sang-Deok KANG, Un-Hae LEE
  • Publication number: 20180363108
    Abstract: Provided according to one embodiment of the present invention are a non-magnetic steel material and a method for manufacturing the same. The steel material comprises 15-27 wt % of manganese, 0.1-1.1 wt % of carbon, 0.05-0.50 wt % of silicon, 0.03 wt % or less (0% exclusive) of phosphorus, 0.01 wt % or less (0% exclusive) of sulfur, 0.050 wt % or less (0% exclusive) of aluminum, 5 wt % or less (0% inclusive) of chromium, 0.01 wt % or less (0% inclusive) of boron, 0.1 wt % or less (0% exclusive) of nitrogen, and a balance amount of Fe and inevitable impurities, has an index of sensitivity of 3.4 or less, the index of sensitivity being represented by the following relational expression (1): [Relational expression 1]—0.451+34.131*P+111.152*Al?799.483*B+0.526*Cr?3.4 (wherein [P], [Al], [B] and [Cr] each mean a wt % of corresponding elements), and contains a microstructure with austenite at an area fraction of 95% or greater therein.
    Type: Application
    Filed: December 23, 2016
    Publication date: December 20, 2018
    Inventors: Un-Hae LEE, Sung-Kyu KIM, Soon-Gi LEE, Yong-Jin KIM, Hong-Yeol OH
  • Publication number: 20180274056
    Abstract: The present invention relates to a wear resistant steel material which can be suitably used for industrial machinery, structural materials, steel materials for slurry pipes, sour steel materials, mining, transportation and storage fields, etc. in the oil gas industry which require properties such as ductility and wear resistance. More particularly, the present invention relates to a wear resistant steel material excellent in toughness and internal quality, and a method for manufacturing the same.
    Type: Application
    Filed: December 16, 2016
    Publication date: September 27, 2018
    Inventors: Yong-Jin KIM, Soon-Gi LEE, Il-Cheol YI, Sung-Kyu KIM, Sang-Deok KANG, Un-Hae LEE