Patents by Inventor Masatoshi Aratani
Masatoshi Aratani 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).
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Patent number: 7018488Abstract: A steel tube having a composition which contains: 0.05 to 0.30% of C; 1.8 to 4.0% of Mn; Si; and Al is subjected to a diameter-reducing rolling process in which the total diameter-reduction rate is no less than 20% and the temperature at which the diameter-reducing rolling process is finished is no higher than 800° C., whereby a structure constituted of martensite and/or bainite or further of ferrite is obtained as a transformation product from the deformed ?. As a result, a steel tube having tensile strength of 1000 MPa or more and excellent three-point-bending property can be obtained. The composition of the steel tube of the present invention may further include at least one type of element selected from the group consisting of Cu, Ni, Cr and Mo, or at least one type of element selected from the group consisting of Nb, V, Ti and B, or at least of one type selected from the group consisting of REM and Ca.Type: GrantFiled: June 14, 2001Date of Patent: March 28, 2006Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Masanori Nishimori, Yoshikazu Kawabata, Akira Yorifuji, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani
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Patent number: 6949728Abstract: An impeder, for manufacturing a welded pipe, including an insulating case 4 containing laminations 10 having coated steel sheets 8 formed by providing an insulating coating on untreated steel sheets having a thickness of 0.3 mm or less and an insulating case 8 containing the laminations, wherein the steel sheets contain 1.5-20% of Cr, 2.5-10% of Si, and 100 ppm or less of C and N in total, or further contain one or more of Al, Mn, and P, where the content of Al is 5% or less and the content of each of Mn and P is 1% or less, the remainder being Fe and unavoidable impurities; and preferably have a resistivity of 60 ??·cm or more.Type: GrantFiled: August 2, 2001Date of Patent: September 27, 2005Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Takatoshi Okabe, Motoaki Itadani, Masatoshi Aratani, Osamu Kondo
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Publication number: 20040155031Abstract: An impeder, for manufacturing a welded pipe, including an insulating case 4 containing laminations 10 having coated steel sheets 8 formed by providing an insulating coating on untreated steel sheets having a thickness of 0.3 mm or less and an insulating case 8 containing the laminations, wherein the steel sheets contain 1.5-20% of Cr, 2.5-10% of Si, and 100 ppm or less of C and N in total, or further contain one or more of Al, Mn, and P, where the content of Al is 5% or less and the content of each of Mn and P is 1% or less, the remainder being Fe and unavoidable impurities; and preferably have a resistivity of 60 &mgr;&OHgr;·cm or more.Type: ApplicationFiled: November 6, 2003Publication date: August 12, 2004Inventors: Takaaki Toyooka, Takatoshi Okabe, Motoaki Itadani, Masatoshi Aratani, Osamu Kondo
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Patent number: 6755919Abstract: A stainless steel tube having excellent formability for secondary operation comprises: a chemical composition including not more than 0.20 mass % of C; not more than 1.5 mass % of Si; not more than 2.0 mass % of Mn; 10-18 mass % of Cr; not more than 0.03 mass % of N; or further at least one type of element selected from the group of: not more than 0.6 mass % of Cu; not more than 0.6 mass % of Ni; not more than 2.5 mass % of Mo; not more than 1.0 mass % of Nb; not more than 1.0 mass % of Ti; and not more than 1.0 mass % of V; Fe as the remainder and the inevitable impurities; and a structure constituted of ferrite or ferrite and martensite, wherein the TE value defined by the following formula exceeds 25,000 Mpa·%, TE=TS×(El+21.9) TS represents the tensile strength in the tube axial direction, and El represents the elongation in such direction.Type: GrantFiled: March 26, 2002Date of Patent: June 29, 2004Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Akira Yorifuji, Makoto Kitazawa, Yoshikazu Kawabata, Motoaki Itadani, Masatoshi Aratani, Takatoshi Okabe
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Patent number: 6749954Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition containing, on the basis of mass percent: about 0.03% to about 0.2% C, about 2.0% or less of Si, not less than about 1.0% to about 1.5% Mn, about 0.1% or less of P, about 0.01% or less of S, about 1.0% or less of Cr, about 0.1% or less of Al, about 0.1% or less of Nb, about 0.1% or less of Ti, about 0.1% or less of V, and about 0.01% or less of N; and by reduction-rolling the treated steel pipe at a cumulative reduction rate of at least about 35% and a final rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of at least about 590 MPa and an n×r product of at least about 0.22. The treated steel pipe is preferably reduction-rolled at a cumulative reduction rate of at least about 20% below the Ar3 transformation point.Type: GrantFiled: May 31, 2002Date of Patent: June 15, 2004Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Akira Yorifuji, Takatoshi Okabe, Takuya Nagahama, Mitsuo Kimura
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Publication number: 20040099355Abstract: The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac1 transformation point—50° C.) to Ac1 transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 &mgr;m is obtained, thus resulting in improved cold workability and induction hardenability.Type: ApplicationFiled: November 19, 2003Publication date: May 27, 2004Applicant: JFE Steel Corporation, a corporation of JapanInventors: Takaaki Toyooka, Yoshikazu Kawabata, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani, Yasue Koyama
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Patent number: 6736910Abstract: The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac1, transformation point −50° C.) to Ac1, transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 &mgr;m is obtained, thus resulting in improved cold workability and induction hardenability.Type: GrantFiled: January 29, 2002Date of Patent: May 18, 2004Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Yoshikazu Kawabata, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani, Yasue Koyama
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Patent number: 6723453Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition containing, on the basis of mass percent: about 0.05% to about 0.2% C; about 0.2% or less of Si; about 1.5% or less of Mn; about 0.1% or less of P; about 0.01% or less of S; about 0.1% or less of Al; and about 0.01% or less of N; and by reduction-rolling the treated steel pipe at a cumulative reduction rate of at least about 35% and a final rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of at least about 400 MPa and an n×r product of at least about 0.22. The treated steel pipe is preferably reduction-rolled at a cumulative reduction rate of at least about 20% below the Ar3 transformation point. The welded steel pipe is suitable for forming structural components.Type: GrantFiled: May 31, 2002Date of Patent: April 20, 2004Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Akira Yorifuji, Takatoshi Okabe, Takuya Nagahama, Mitsuo Kimura
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Patent number: 6682829Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition comprising, on the basis of mass percent: about 0.05% to about 0.3% C; about 2.0% or less of Si; more than about 1.5% to about 5.0% Mn; about 0.1% or less of P; about 0.01% or less of S; about 0.1% or less of Cr; about 0.1% or less of Al; about 0.1% or less of Nb; about 0.3% or less of Ti; and about 0.01% or less of N; and by diameter-reduction-rolling the treated steel pipe at a accumulated diameter reduction rate of at least about 35% and a finish rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of about 780 MPa or more and a n×r product of at least about 0.15. The treated steel pipe is preferably diameter-reduction-rolled at a accumulated diameter reduction rate of at least about 20% below the Ar3 transformation point.Type: GrantFiled: May 31, 2002Date of Patent: January 27, 2004Assignee: JFE Steel CorporationInventors: Takaaki Toyooka, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Akira Yorifuji, Takatoshi Okabe, Takuya Nagahama, Mitsuo Kimura
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Publication number: 20030145913Abstract: The invention provides a steel pipe being superior in workability, particularly in bending workability, in which an r-value in the axial direction of the pipe in a portion where melting or transformation of a steel material has occurred during seam welding is as high as comparable to that in a portion where melting or transformation of the steel material has not occurred, and a method of producing the steel pipe. In the high-workability steel pipe, an r-value in the longitudinal direction is not less than 1.2, more preferably not less than 1.6, over an entire area in the circumferential direction, including a seamed portion. The steel pipe is produced by a method comprising the step of performing diameter-reducing rolling on a steel pipe in a temperature range of from 600° C.Type: ApplicationFiled: October 30, 2002Publication date: August 7, 2003Inventors: Takaaki Toyooka, Yoshikazu Kawabata, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani
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Publication number: 20030057695Abstract: A stainless steel tube for a automobile structure member having excellent formability for secondary operation comprises: a chemical composition including not more than 0.20 mass % of C; not more than 1.5 mass % of Si; not more than 2.0 mass % of Mn; 10-18 mass % of Cr; not more than 0.03 mass % of N; or further at least one type of element selected from the group of: not more than 0.6 mass % of Cu; not more than 0.6 mass % of Ni; not more than 2.5 mass % of Mo; not more than 1.0 mass % of Nb; not more than 1.0 mass % of Ti; and not more than 1.0 mass % of V; Fe as the remainder and the inevitable impurities; and a structure which is constituted of ferrite or ferrite and martensite, wherein the TE value defined by the following formula (1) exceeds 25,000 MPa·%.Type: ApplicationFiled: March 26, 2002Publication date: March 27, 2003Inventors: Takaaki Toyooka, Akira Yorifuji, Makoto Kitazawa, Yoshikazu Kawabata, Motoaki Itadani, Masatoshi Aratani, Takatoshi Okabe
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Publication number: 20030051782Abstract: A steel tube having a composition which contains: 0.05 to 0.30% of C; 1.8 to 4.0% of Mn; Si; and Al is subjected to a diameter-reducing rolling process in which the total diameter-reduction rate is no less than 20% and the temperature at which the diameter-reducing rolling process is finished is no higher than 800 ° C., whereby a structure constituted of martensite and/or bainite or further of ferrite is obtained as a transformation product from the deformed &ggr;. As a result, a steel tube having tensile strength of 1000 MPa or more and excellent three-point-bending property can be obtained. The composition of the steel tube of the present invention may further include at least one type of element selected from the group consisting of Cu, Ni, Cr and Mo, or at least one type of element selected from the group consisting of Nb, V, Ti and B, or at least of one type selected from the group consisting of REM and Ca.Type: ApplicationFiled: August 26, 2002Publication date: March 20, 2003Inventors: Takaaki Toyooka, Masanori Nishimori, Yoshikazu Kawabata, Akira Yorifuji, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani
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Publication number: 20030044638Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition comprising, on the basis of mass percent: about 0.05% to about 0.3% C; about 2.0% or less of Si; more than about 1.5% to about 5.0% Mn; about 0.1% or less of P; about 0.01% or less of S; about 0.1% or less of Cr; about 0.1% or less of Al; about 0.1% or less of Nb; about 0.3% or less of Ti; and about 0.01% or less of N; and by diameter-reduction-rolling the treated steel pipe at a accumulated diameter reduction rate of at least about 35% and a finish rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of about 780 MPa or more and a n×r product of at least about 0.15. The treated steel pipe is preferably diameter-reduction-rolled at a accumulated diameter reduction rate of at least about 20% below the Ar3 transformation point.Type: ApplicationFiled: May 31, 2002Publication date: March 6, 2003Applicant: KAWASAKI STEEL CORPORATIONInventors: Takaaki Toyooka, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Akira Yorifuji, Takatoshi Okabe, Takuya Nagahama, Mitsuo Kimura
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Publication number: 20030008171Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition containing, on the basis of mass percent: about 0.03% to about 0.2% C, about 2.0% or less of Si, not less than about 1.0% to about 1.5% Mn, about 0.1% or less of P, about 0.01% or less of S, about 1.0% or less of Cr, about 0.1% or less of Al, about 0.1% or less of Nb, about 0.1% or less of Ti, about 0.1% or less of V, and about 0.01% or less of N; and by reduction-rolling the treated steel pipe at a cumulative reduction rate of at least about 35% and a final rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of at least about 590 MPa and an n×r product of at least about 0.22. The treated steel pipe is preferably reduction-rolled at a cumulative reduction rate of at least about 20% below the Ar3 transformation point.Type: ApplicationFiled: May 31, 2002Publication date: January 9, 2003Applicant: KAWASAKI STELL CORPORATIONInventors: Takaaki Toyooka, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Akira Yorifuji, Takatoshi Okabe, Takuya Nagahama, Mitsuo Kimura
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Publication number: 20020192495Abstract: A welded steel pipe is formed by heating or soaking an untreated welded steel pipe having a steel composition containing, on the basis of mass percent: about 0.05 % to about 0.2% C; about 0.2% or less of Si; about 1.5% or less of Mn; about 0.1% or less of P; about 0.01% or less of S; about 0.1% or less of Al; and about 0.01 % or less of N; and by reduction-rolling the treated steel pipe at a cumulative reduction rate of at least about 35% and a final rolling temperature of about 500° C. to about 900° C. The welded steel pipe exhibits excellent hydroformability, i.e., has a tensile strength of at least about 400 MPa and an n×r product of at least about 0.22. The treated steel pipe is preferably reduction-rolled at a cumulative reduction rate of at least about 20% below the Ar3 transformation point. The welded steel pipe is suitable for forming structural components.Type: ApplicationFiled: May 31, 2002Publication date: December 19, 2002Applicant: Kawasaki Steel CorporationInventors: Takaaki Toyooka, Masatoshi Aratani, Yoshikazu Kawabata, Yuji Hashimoto, Akira Yorifuji, Takatoshi Okabe, Takuya Nagahama, Mitsuo Kimura
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Publication number: 20020153070Abstract: The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac1, transformation point −50° C.) to Ac1, transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 &mgr;m is obtained, thus resulting in improved cold workability and induction hardenability.Type: ApplicationFiled: January 29, 2002Publication date: October 24, 2002Inventors: Takaaki Toyooka, Yoshikazu Kawabata, Akira Yorifuji, Masanori Nishimori, Motoaki Itadani, Takatoshi Okabe, Masatoshi Aratani, Yasue Koyama
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Patent number: 6221180Abstract: The invention provides a can steel sheet having satisfactory surface appearance and having workability, appearance property after working and high yield that can meet demands on complicated can forming, and a manufacturing process thereof. To be more specific, according to the invention, a slab having a composition containing, in weight %, C: more than 0.005% and equal to or less than 0.1%, Mn: 0.05-1.0% is subjected to hot-rolling at a finishing temperature of 800 to 1000° C., to coiling at 500 to 750° C., to cold-rolling, followed by continuous annealing at a recrystallization temperature or higher and 800° C. or lower, and then to box annealing at a temperature higher than 500° C. and equal to or lower than 600° C. for 1 hr or longer. The steel sheet has preferably a structure containing ferrite as a principle phase and having a mean grain diameter of 10 &mgr;m or less and further containing 0.1-1% by weight of pearlite grains each having a grain diameter of 0.5-3 &mgr;m.Type: GrantFiled: December 7, 1999Date of Patent: April 24, 2001Assignee: Kawasaki Steel CorporationInventors: Akio Tosaka, Masatoshi Aratani, Osamu Furukimi, Hideo Kuguminato, Makoto Aratani, Yuji Miki
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Patent number: 6171416Abstract: At least both ends of a sheet bar in the length direction, which is obtained by roughly rolling a steel slab including 0.1 wt % or less of C, 0.5 wt % or less of Si, 1.0 wt % or less of Mn, 0.1 wt % or less of P, 0.05 wt % or less of S, 0.20 wt % or less of Al, and 0.015 wt % or less of N, are heated so that the temperature at both ends of the sheet bar in the length direction is 15° C. or more higher than the temperature of the remainder of the sheet bar. The rolling finish temperature is Ar3+20° C. to Ar3+100° C. in both end portions of the sheet bar in the length direction, and Ar3+10° C. to Ar3+60° C. in the remainder, and the rolling finish temperature in the both end portions in the length direction is 10° C. or more higher than that of the remainder, so that a steel strip after cold rolling and annealing has r values within ±0.3 of the average r value, and &Dgr;r within ±0.Type: GrantFiled: October 26, 1999Date of Patent: January 9, 2001Assignee: Kawasaki Steel CorporationInventors: Makoto Aratani, Yukio Kobata, Hideo Kuguminato, Akio Tosaka, Masatoshi Aratani, Susumu Okada
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Patent number: 6110299Abstract: A steel sheet for double-rolled tubes has excellent formability, and excellent strength and toughness after forming and heat treatment of a tube because of suppressed coarsening of the ferrite grain size and a method for making the same comprises: hot finish-rolling of a steel material containing C: 0.0005-0.020 wt %, and one or two of Nb: 0.003-0.040 wt %, and Ti: 0.005-0.060 wt % at a final temperature of 1,000-850.degree. C., coiling at 750.degree. C. or less, cold rolling, continuous annealing at 650.degree. C.-850.degree. C. for 20 seconds or less, and second cold-rolling at a rolling reduction rate of 20% or less, so that at least one of Nb and Ti is present in a solid solution state in an amount of 0.005 wt % or more, and the crystal grain size in the ferrite structure is in the range of 5 to 10 .mu.m.Type: GrantFiled: June 24, 1998Date of Patent: August 29, 2000Assignee: Kawasaki Steel CorporationInventors: Akio Tosaka, Kaneharu Okuda, Masatoshi Aratani
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Patent number: 6042952Abstract: A steel slab is rough-rolled into a sheet bar and butt-joined onto a preceding sheet bar and a widthwise end portion of the sheet bar is heated by means of an edge heater and then subjected to a continuous finish rolling through pair-cross rolls rolling on at least 3 stands to provide a hot rolled steel strip having a width of not less than 950 mm, a thickness of 0.5-2 mm and a crown within .+-.40 .mu.m, and the hot rolled steel strip is subjected to cold rolling, continuous annealing, temper rolling and, if necessary, plating treatment on the surface of the cold rolled steel strip, whereby there is obtained a steel sheet having an average thickness of not more than 0.20 mm and a width of not less than 950 mm, a thickness variation quantity in a widthwise direction is within .+-.4% of the average thickness in a region corresponding to not less than 95% of the width of the steel sheet as cold rolled and a hardness (HR30T) variation in the widthwise direction is within .+-.3 of an average hardness.Type: GrantFiled: November 12, 1997Date of Patent: March 28, 2000Assignee: Kawasaki Steel CorporationInventors: Makoto Aratani, Naotoshi Ryu, Hideo Kuguminato, Akio Tosaka, Kaneharu Okuda, Masatoshi Aratani, Susumu Okada