Patents by Inventor Jeong W. Jo

Jeong W. Jo 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: 5565044
    Abstract: A thermal refiningless, hot-rolled steel exhibits impact strength in excess of 10kgf.multidot.m/cm.sup.2 and contains, expressed in terms of weight percent, 0.30-0.50% carbon, 0.15-0.60% silicon, 0.80-1.60% manganese, up to 0.02% phosphorus, up to 0.015% sulfur, 0.07-0.20% vanadium, 0.015-0.06% aluminum, 0.005-0.015% nitrogen, up to 0.0015% oxygen, the balance iron and unavoidable impurities. The steel of the above-identified property and composition is produced by casting a steel product of predetermined cross-sectional shape; heating the steel product up to a temperature of 1,100.degree.-1,250.degree. C.; hot-rolling the heated steel product at a final rolling temperature of 850.degree.1,000.degree. C.; normalizing the hot-rolled steel product at a temperature of 880.degree.-950.degree. C.; and cooling the normalized steel product down to 300.degree. C. at a cooling speed of 5.degree.-100.degree. C./min.
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: October 15, 1996
    Assignees: Daewoo Heavy Industries, Ltd., Kia Steel Co., Ltd.
    Inventors: Dae Y. Kim, Jeong W. Jo, Yoon S. Jo, Jong S. Kim