Patents by Inventor Junichiro Hirasawa

Junichiro Hirasawa 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: 10988853
    Abstract: Stainless steel sheets including a Ni and O-containing coating on the surface that has excellent weld penetration characteristics and excellent crevice corrosion resistance, and a method for producing such stainless steel sheets. A stainless steel sheet includes a Ni and O-containing coating on a surface of the stainless steel sheet. The Ni and O-containing coating has a coating weight of greater than or equal to 0.1 g/m2 and less than or equal to 20 g/m2. The Ni and O-containing coating has a composition including, in at. %, Ni: greater than or equal to 25% and less than or equal to 60%, and O: greater than or equal to 40% and less than or equal to 70%.
    Type: Grant
    Filed: January 5, 2017
    Date of Patent: April 27, 2021
    Assignee: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Shin Ishikawa, Chikara Kami, Shinji Ootsuka
  • Patent number: 10272513
    Abstract: The ferritic stainless steel sheet contains, in mass%, C: 0.020% or less, Si: 0.6% or less, Mn: 0.5% or less, P: 0.04% or less, S: 0.010% or less, Al: 0.015% or more and 0.20% or less, Cr: 17.0% or more and 24.0% or less, Ni: less than 0.6%, N: 0.020% or less, Ca: 0.0002% or more and 0.0020% or less, and O: 0.0050% or less and further contains one or two selected from Ti: 0.01% or more and 0.45% or less and Nb: 0.01% or more and 0.55% or less, with the balance being Fe and unavoidable impurities. The ferritic stainless steel sheet satisfies (Ti+Nb×48/93)/(C+N)?8.0 (where Ti, Nb, C, and N represent the contents (% by mass) of these elements, respectively).
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: April 30, 2019
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Shin Ishikawa, Chikara Kami
  • Publication number: 20190032236
    Abstract: The present invention provides stainless steel sheets including a Ni and O-containing coating on the surface and having excellent weld penetration characteristics and excellent crevice corrosion resistance, and provides a method for producing such stainless steel sheets. A stainless steel sheet includes a Ni and O-containing coating on a surface of the stainless steel sheet. The Ni and O-containing coating has a coating weight of greater than or equal to 0.1 g/m2 and less than or equal to 20 g/m2. The Ni and O-containing coating has a composition including, in at. %, Ni: greater than or equal to 25% and less than or equal to 60%, and O: greater than or equal to 40% and less than or equal to 70%.
    Type: Application
    Filed: January 5, 2017
    Publication date: January 31, 2019
    Applicant: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Shin Ishikawa, Chikara Kami, Shinji Ootsuka
  • Publication number: 20180345317
    Abstract: A lubricant coating material for stainless steel sheets that has excellent press formability (deep drawability and mold galling resistance) and a lubricated stainless steel sheet in which the same is used includes: a lubricant coating material for stainless steel sheets that contains an acrylic resin and polyethylene wax, the polyethylene wax having a melting point of 115° C. or greater, and the content of the polyethylene wax ranging from greater than 20 parts by mass to 50 parts by mass with respect to 100 parts by mass of the acrylic resin; and a lubricated stainless steel sheet in which the same is used.
    Type: Application
    Filed: December 2, 2016
    Publication date: December 6, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Junichiro HIRASAWA, Takayoshi YANO, Shin ISHIKAWA, Chikara KAMI
  • Publication number: 20180195157
    Abstract: Provided is a ferritic stainless steel sheet for a urea SCR casing which is excellent in terms of corrosion resistance in a urea SCR environment and which increases the durability of a urea SCR casing. The steel sheet has a chemical composition containing, by mass %, C: 0.020% or less, Si: 0.01% or more and 0.50% or less, Mn: 0.01% or more and 0.50% or less, P: 0.040% or less, S: 0.010% or less, Al: 0.01% or more and 0.20% or less, Cr: 20.5% or more and 24.0% or less, Cu: 0.40% or more and 0.80% or less, Ni: 0.05% or more and 0.6% or less, N: 0.020% or less, one or both selected from among Ti: 0.01% or more and 0.40% or less and Nb: 0.01% or more and 0.55% or less, and the balance being Fe and inevitable impurities, in which the relationship Ti+Nb×48/93?8×(C+N) (in the relational expression, Ti, Nb, C, and N denote the contents (mass %) of the corresponding chemical elements) is satisfied.
    Type: Application
    Filed: July 27, 2015
    Publication date: July 12, 2018
    Applicant: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Takayoshi Yano, Shin Ishikawa, Chikara Kami
  • Publication number: 20170266751
    Abstract: The ferritic stainless steel sheet contains, in mass %, C: 0.020% or less, Si: 0.6% or less, Mn: 0.5% or less, P: 0.04% or less, S: 0.010% or less, Al: 0.015% or more and 0.20% or less, Cr: 17.0% or more and 24.0% or less, Ni: less than 0.6%, N: 0.020% or less, Ca: 0.0002% or more and 0.0020% or less, and O: 0.0050% or less and further contains one or two selected from Ti: 0.01% or more and 0.45% or less and Nb: 0.01% or more and 0.55% or less, with the balance being Fe and unavoidable impurities. The ferritic stainless steel sheet satisfies (Ti+Nb×48/93)/(C+N)?8.0 (where Ti, Nb, C, and N represent the contents (% by mass) of these elements, respectively).
    Type: Application
    Filed: May 12, 2015
    Publication date: September 21, 2017
    Applicant: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Shin Ishikawa, Chikara Kami
  • Patent number: 9090952
    Abstract: A high-strength cold-rolled steel sheet having high chemical convertibility and a tensile strength of 590 MPa or more and a method for producing such a steel sheet are provided. The steel sheet contains, in terms of percent by mass, C: 0.05 to 0.3%, Si: 0.6 to 3.0%, Mn: 1.0 to 3.0%, P: 0.1% or less, S: 0.05% or less, Al: 0.01 to 1%, N: 0.01% or less, and the balance being Fe and unavoidable impurities. The coverage ratio of reduced iron on a steel sheet surface is 40% or more. In order to produce such a steel sheet, an oxidation treatment is performed after cold rolling. Subsequently, annealing is conducted in a furnace in a 1 to 10 vol % H2+balance N2 gas atmosphere with a dew point of ?25° C. or less.
    Type: Grant
    Filed: December 24, 2010
    Date of Patent: July 28, 2015
    Assignee: JFE Steel Corporation
    Inventors: Yoichi Makimizu, Yoshitsugu Suzuki, Mai Miyata, Naoto Yoshimi, Junichiro Hirasawa, Shinji Otsuka, Hideki Nagano, Kohei Hasegawa
  • Patent number: 8911574
    Abstract: A method for manufacturing high-Si cold rolled steel sheets includes heating a cold rolled steel sheet with a direct flame burner (A) having an air ratio of not more than 0.89 when the temperature of the cold rolled steel sheet that is being increased is in the temperature range of not less than 300° C. and less than Ta° C., subsequently heating the cold rolled steel sheet with a direct flame burner (B) having an air ratio of not less than 0.95 when the temperature of the cold rolled steel sheet is in the temperature range of not less than Ta° C. and less than Tb° C., and subsequently soak-annealing the cold rolled steel sheet in a furnace having an atmospheric gas composition which has a dew point of not more than ?25° C. and contains 1 to 10 volume % of H2 and the balance of N2.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: December 16, 2014
    Assignee: JFE Steel Corporation
    Inventors: Shinji Ootsuka, Junichiro Hirasawa, Hideyuki Takahashi, Naoto Yoshimi, Hideki Nagano
  • Patent number: 8852361
    Abstract: A stainless steel sheet with excellent heat and corrosion resistances for a brake disk is provided. Specifically, in mass %, C: less than 0.10%, Si: 1.0% or less, Mn: 1.0 to 2.5%, P: 0.04% or less, S: 0.01% or less, Cr: more than 11.5% but not more than 15.0%, Ni: 0.1 to 1.0%, Al: 0.10% or less, Nb: more than 0.08% but not more than 0.6%, V: 0.02 to 0.3%, and N: more than 0.03% but not more than 0.10% are contained so that 0.03?{C+N?(13/93)Nb}?0.10, (5Cr+10Si+15Mo+30Nb+50V?9Ni?5Mn?3Cu?225N?270C)?45, and {(14/50)V+(14/90)Nb}<N (wherein Cr, Si, Mo, Nb, Ni, Mn, Cu, V, N, and C represent the contents (mass %) of the corresponding elements) are satisfied. With such a composition, the stainless steel sheet for a brake disk can be provided with both excellent heat resistance and excellent corrosion resistance after tempering.
    Type: Grant
    Filed: October 20, 2005
    Date of Patent: October 7, 2014
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Patent number: 8668789
    Abstract: A method for the manufacturing of high strength cold rolled steel sheets includes continuously annealing a cold rolled steel sheet that has a composition containing C: 0.05-0.3% mass, Si: 0.6-3.0% mass, Mn: 1.0-3.0% mass, P: ?0.1% mass, S: ?0.02% mass, Al: 0.01-1% mass, N: ?0.01% mass, and Fe and inevitable impurities: balance, in a manner such that the cold rolled steel sheet is heated in a furnace using an oxidizing burner to a steel sheet temperature of ?700° C., then soak-annealed in a reducing atmosphere furnace at 750-900° C., then cooled so the average cooling rate between 500° C. and 100° C. is ?50° C./s. High-Si cold rolled steel sheets with high strength and good phosphatability while containing Si?0.6% are obtained without controlling conditions so as to increase the dew point in the reducing atmosphere in the soaking furnace or to increase the vapor hydrogen partial pressure ratio.
    Type: Grant
    Filed: July 27, 2010
    Date of Patent: March 11, 2014
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Naoto Yoshimi, Hiroki Nakamaru, Kohei Hasegawa, Hideyuki Tsurumaru, Keita Yonetsu, Hideyuki Takahashi, Masato Sasaki
  • Patent number: 8657971
    Abstract: A brake disk excellent in temper softening resistance and toughness comprising, by mass, 0.1% or less of C, 1.0% or less of Si, 2.0% or less of Mn, 10.5% to 15.0% of Cr, and 0.1% or less of N, the remainder being Fe and unavoidable impurities, such that the following inequalities are satisfied: 5Cr+10Si+15Mo+30Nb?9Ni?5Mn?3Cu?225N?270C<45 (1) and 0.03?{C+N?(13/92)Nb}?0.09 (2) wherein Cr, Si, Mo, Nb, Ni, Mn, Cu, N, and C each represent the content of the corresponding elements on a mass percent basis, and having a martensitic structure having prior-austenite grains with an average diameter of 8 to less than 15 ?m.
    Type: Grant
    Filed: October 5, 2006
    Date of Patent: February 25, 2014
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Publication number: 20130048157
    Abstract: A method for manufacturing high-Si cold rolled steel sheets includes heating a cold rolled steel sheet with a direct flame burner (A) having an air ratio of not more than 0.89 when the temperature of the cold rolled steel sheet that is being increased is in the temperature range of not less than 300° C. and less than Ta° C., subsequently heating the cold rolled steel sheet with a direct flame burner (B) having an air ratio of not less than 0.95 when the temperature of the cold rolled steel sheet is in the temperature range of not less than Ta° C. and less than Tb° C., and subsequently soak-annealing the cold rolled steel sheet in a furnace having an atmospheric gas composition which has a dew point of not more than ?25° C. and contains 1 to 10 volume % of H2 and the balance of N2.
    Type: Application
    Filed: March 28, 2011
    Publication date: February 28, 2013
    Applicant: JFE STEEL CORPORATION
    Inventors: Shinji Ootsuka, Junichiro Hirasawa, Hideyuki Takahashi, Naoto Yoshimi, Hideki Nagano
  • Patent number: 8357247
    Abstract: A martensitic stainless steel, having high temper softening resistance, for disc brakes is provided. The martensitic stainless steel is not seriously softened by maintaining the steel at more than 600° C. The steel has a hardness of 32 or more or a hardness of 30 or more in HRC after the steel is tempered at 650° C. for one hour or tempered at 670° C. for one hour, respectively. In particular, the martensitic stainless steel for disc brakes contains less than 0.050 mass % carbon, 1.0 mass % or less silicon, 2.0 mass % or less manganese, 0.04 mass % or less phosphorus, 0.010 mass % or less sulfur, 0.2 mass % or less aluminum, more than 11.5 mass % to 15.0 mass % chromium, 0.5 mass % to 2.0 mass % nickel, more than 0.50 mass % to 4.0 mass %. copper, more than 0.08 mass % to 0.6 mass % niobium, and less than 0.09 mass % nitrogen, the remainder being iron and unavoidable impurities.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: January 22, 2013
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Yoshihiro Ozaki, Takumi Ujiro, Osamu Furukimi
  • Publication number: 20120325376
    Abstract: A high-strength cold-rolled steel sheet having high chemical convertibility and a tensile strength of 590 MPa or more and a method for producing such a steel sheet are provided. The steel sheet contains, in terms of percent by mass, C: 0.05 to 0.3%, Si: 0.6 to 3.0%, Mn: 1.0 to 3.0%, P: 0.1% or less, S: 0.05% or less, Al: 0.01 to 1%, N: 0.01% or less, and the balance being Fe and unavoidable impurities. The coverage ratio of reduced iron on a steel sheet surface is 40% or more. In order to produce such a steel sheet, an oxidation treatment is performed after cold rolling. Subsequently, annealing is conducted in a furnace in a 1 to 10 vol % H2+balance N2 gas atmosphere with a dew point of ?25° C. or less.
    Type: Application
    Filed: December 24, 2010
    Publication date: December 27, 2012
    Applicant: JFE STEEL CORPORATION
    Inventors: Yoichi Makimizu, Yoshitsugu Suzuki, Mai Miyata, Naoto Yoshimi, Junichiro Hirasawa, Shinji Otsuka, Hideki Nagano, Kohei Hasegawa
  • Publication number: 20120186707
    Abstract: A method for the manufacturing of high strength cold rolled steel sheets includes continuously annealing a cold rolled steel sheet that has a composition containing C: 0.05-0.3% mass, Si: 0.6-3.0% mass, Mn: 1.0-3.0% mass, P: 0.1% mass, S: ?0.02% mass, Al: 0.01-1% mass, N: ?0.01% mass, and Fe and inevitable impurities: balance, in a manner such that the cold rolled steel sheet is heated in a furnace using an oxidizing burner to a steel sheet temperature of ?700° C., then soak-annealed in a reducing atmosphere furnace at 750-900° C., then cooled so the average cooling rate between 500° C. and 100° C. is ?50° C./s. High-Si cold rolled steel sheets with high strength and good phosphatability while containing Si?0.6% are obtained without controlling conditions so as to increase the dew point in the reducing atmosphere in the soaking furnace or to increase the vapor hydrogen partial pressure ratio.
    Type: Application
    Filed: July 27, 2010
    Publication date: July 26, 2012
    Applicant: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Naoto Yoshimi, Hiroki Nakamaru, Kohei Hasegawa, Hideyuki Tsurumaru, Keita Yonetsu, Hideyuki Takahashi, Masato Sasaki
  • Publication number: 20120048662
    Abstract: A martensitic stainless steel for disc brakes, having high temper softening resistance. The martensitic stainless steel is not seriously softened by maintaining the steel at more than 600° C. The martensitic stainless steel contains less than 0.050 mass % carbon, 1.0 mass % or less silicon, 2.0 mass % or less manganese, 0.04 mass % or less phosphorus, 0.010 mass % or less sulfur, 0.2 mass % or less aluminum, more than 11.5 mass % to 15.0 mass % chromium, 0.5 mass % to 2.0 mass % nickel, more than 0.50 mass % to 4.0 mass % copper, more than 0.08 mass % to 0.6 mass % niobium, and less than 0.09 mass % nitrogen, the remainder being iron and unavoidable impurities.
    Type: Application
    Filed: October 5, 2011
    Publication date: March 1, 2012
    Applicant: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Yoshihiro Ozaki, Takumi Ujiro, Osamu Furukimi
  • Patent number: 7572407
    Abstract: A martensitic stainless steel sheet having superior corrosion resistance, toughness at the weld zones, and workability. The composition of the steel sheet is, on a mass basis: less than about 0.02% of carbon; about 1.0% or less of silicon; less than about 1.5% of manganese; about 0.04% or less of phosphorus; about 0.01% or less of sulfur; about 0.1% or less of aluminum; about 1.5% or more and less than about 4.0% of nickel; about 11% or more and less than about 15% of chromium; about 0.5% or more and less than about 2.0% of molybdenum; and less than about 0.02% of nitrogen, the balance being iron and unavoidable impurities, wherein 15.0%?[Cr]+1.5×[Mo]+1.2×[Ni]?20.0%; [C]+[N]<0.030%; [Ni]+0.5×([Mn]+[Mo])+30×[C]>3.0%; and 8.0%?72×[C]+40×[N]+3×[Si]+2×[Mn]+4×[Ni]+[Mo]?18.0%.
    Type: Grant
    Filed: December 23, 2002
    Date of Patent: August 11, 2009
    Assignee: JFE Steel Corporation
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Publication number: 20090162240
    Abstract: A brake disk including, by mass, 0.1% or less of C, 1.0% or less of Si, 2.0% or less of Mn, 10.5% to 15.0% of Cr, 2.0% or less of Ni, greater than 0.5% to 4.0% of Cu, 0.02% to 0.3% of Nb, and 0.1% or less of N and further including N, Nb, Cr. Si, Ni, Mn, Mo, and Cu, the remainder being Fe and unavoidable impurities, such that the following inequalities are satisfied: 5Cr+10Si+15Mo+30Nb?9Ni?5Mn?3Cu?225N?270C<45??(1) 0.03?{C+N?(13/93)Nb}?0.09??(2) and having a martensitic structure having prior-austenite grains with an average diameter of 8 ?m or more, a hardness of 32 to 38 HRC, and high temper softening resistance.
    Type: Application
    Filed: October 5, 2006
    Publication date: June 25, 2009
    Applicant: JFE Steel Corp.
    Inventors: Junichiro Hirasawa, Takako Yamashita, Noriko Makiishi, Etsuo Hamada, Takumi Ujiro, Osamu Furukimi
  • Publication number: 20090104068
    Abstract: A brake disk excellent in temper softening resistance and toughness comprising, by mass, 0.1% or less of C, 1.0% or less of Si, 2.0% or less of Mn, 10.5% to 15.0% of Cr, and 0.1% or less of N, the remainder being Fe and unavoidable impurities, such that the following inequalities are satisfied: 5Cr+10Si+15Mo+30Nb?9Ni—5Mn—3Cu?225N?270C<45 (1) and 0.03?{C+N?(13/92)Nb}?0.09 (2) wherein Cr, Si, Mo, Nb, Ni, Mn, Cu, N, and C each represent the content of the corresponding elements on a mass percent basis, and having a martensitic structure having prior-austenite grains with an average diameter of 8 to less than 15 ?m.
    Type: Application
    Filed: October 5, 2006
    Publication date: April 23, 2009
    Applicant: JFE STEEL CORPORATION
    Inventors: Junichiro Hirasawa, Takumi Ujiro, Osamu Furukimi
  • Patent number: RE44709
    Abstract: The soft Cr-containing steel includes, on a % by mass basis, C: from about 0.001% to about 0.020%, Si: more than about 0.10% and less than about 0.50%, Mn: less than about 2.00%, P: less than about 0.060%, S: less than about 0.008%, Cr: from about 12.0% to about 16.0%, Ni: from about 0.05% to about 1.00%, N: less than about 0.020%, Nb: from about 10×(C+N) to about 1.00%, Mo: more than about 0.80% and less than about 3.00%, wherein the contents of alloying elements, represented by Si and Mo, respectively, on a % by mass, satisfy the formula Si?1.2-0.4 Mo, so as to prevent precipitation of the Laves phase and to stably secure an effect of increasing high-temperature strength due to solid solution Mo.
    Type: Grant
    Filed: May 13, 2009
    Date of Patent: January 21, 2014
    Assignee: JFE Steel Corporation
    Inventors: Atsushi Miyazaki, Junichiro Hirasawa, Mineo Muraki, Yoshihiro Yazawa, Osamu Furukimi