Patents by Inventor Hitoshi Misao

Hitoshi Misao 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: 5496514
    Abstract: A fracture resistant stainless steel sheet comprises: non-metallic inclusions of Al.sub.2 O.sub.3, MnO, and SiO.sub.2 which inevitably exist in stainless steel; the non-metallic inclusions having a composition situated in a region defined by nine points in a phase diagram of a 3-component system of "Al.sub.2 O.sub.3 --MnO--SiO.sub.2 "; the stainless steel sheet having an 1.0% on-set stress of at least 1520 N/mm.sup.2 (155 kgf/mm.sup.2); the stainless steel sheet having an anisotropic difference of 1.0% on-set stress of 196 N/mm.sup.2 (20 kgf/mm.sup.2) or less; and the stainless steel sheet having a Erichsen number of at least 4.6 mm.A method for producing a high fracture resistant stainless steel sheet comprises the steps of: preparing a stainless steel strip; applying to the stainless steel strip a process of annealing--pickling --first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: March 5, 1996
    Assignee: NKK Corporation
    Inventors: Katsuhisa Yamauchi, Hitoshi Misao, Tadashi Inoue, Tomoyoshi Okita
  • Patent number: 5407493
    Abstract: A fracture resistant stainless steel sheet comprises: non-metallic inclusions of Al.sub.2 O.sub.3, MnO, and SiO.sub.2 which inevitably exist in stainless steel; the non-metallic inclusions having a composition situated in a region defined by nine points in a phase diagram of a 3-component system of "Al.sub.2 O.sub.3 -MnO-SiO.sub.2 "; the stainless steel sheet having an 1.0% on-set stress of at least 1520 N/mm.sup.2 (155 kgf/mm.sup.2); the stainless steel sheet having an anisotropic difference of 1.0% on-set stress of 196 N/mm.sup.2 (20 kgf/mm.sup.2) or less; and the stainless steel sheet having a punch test work load of at least 25 kgf.multidot.mm or more.A method for producing a high fracture resistant stainless steel sheet comprises the steps of: preparing a stainless steel strip; applying to the stainless steel strip a process of annealing--pickling --first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: April 18, 1995
    Assignee: NKK Corporation
    Inventors: Katsuhisa Yamauchi, Hitoshi Misao, Tadashi Inoue, Tomoyoshi Okita
  • Patent number: 5314549
    Abstract: A stainless steel sheet essentially consisting of: 0.01 to 0.2 wt. % C, 0.1 to 2 wt. % Si, 0.1 to 2 wt. % Mn, 4 to 11 wt. % Ni, 13 to 20 wt. % Cr, 0.01 to 0.2 wt. % N, 0.0005 to 0.0025 wt. % sol.Al, 0.002 to 0.01 wt. % O, 0.009 wt. % or less S, and the balance being Fe and inevitable impurities; the sheet containing 40 to 90% martensite; and the steel sheet having a 1400 N/mm.sup.2 or more tensile stress when a tensile strain is 1.0%. The invention also provides a method for producing a stainless steel sheet comprising the steps of: applying to the steel sheet a process of first cold rolling (CR.sub.1)--first intermediate annealing--second cold rolling (CR.sub.2)--second intermediate annealing--third cold rolling (CR.sub.3)--the final annealing--fourth cold rolling (CR.sub.4)--low temperature heat treatment; the first-, second- and third cold reduction ratio being 30% to 60%; the annealing temperatures in the first-, second- and final annealing being in the range of 950.degree. C. to 1100.degree. C.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: May 24, 1994
    Assignee: NKK Corporation
    Inventors: Hitoshi Misao, Katsuhisa Yamauchi, Tadashi Inoue, Tomoyoshi Okita