Patents by Inventor Takuya Tanahashi
Takuya Tanahashi 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).
-
Publication number: 20230193438Abstract: A welded rail according to an aspect of the present invention includes: a plurality of rail portions having a head portion and a web portion and having a height h; and a welded joint portion that joins the rail portions together, in which the rail portion has a predetermined chemical composition, a HAZ width of the welded joint portion is 60 mm or less, in a region of 0 to (?)×h from a head top portion outer surface in a cross section of the welded joint portion which is parallel to a longitudinal direction and an up-down direction of the welded rail and passes through a center of the welded joint portion and of ±5 mm in the longitudinal direction from a welding center, an area ratio of a martensite structure is 0.0006% or more and 0.1000% or less, and in the region, the number of martensite structures having a grain size of 20 to 200 ?m is 3 to 80.Type: ApplicationFiled: September 21, 2021Publication date: June 22, 2023Applicant: NIPPON STEEL CORPORATIONInventors: Masaharu UEDA, Kenji SAITA, Teruhisa MIYAZAKI, Takuya TANAHASHI
-
Publication number: 20220120039Abstract: A rail including a predetermined chemical composition is provided, in which 90 area % or greater of a metallographic structure in a cross section of a rail web portion is a pearlite structure, a minimum value of a hardness in the cross section of the rail web portion is Hv 300 or greater, and a difference between a maximum value and the minimum value of the hardness in the cross section of the rail web portion is Hv 40 or less.Type: ApplicationFiled: March 2, 2020Publication date: April 21, 2022Applicant: NIPPON STEEL CORPORATIONInventors: Masaharu UEDA, Teruhisa MIYAZAKI, Takuya TANAHASHI, Yusuke MAEDA
-
Publication number: 20210395847Abstract: According to one aspect of the present invention, what is provided is a rail including, by mass %: C: 0.75% to 1.20%; Si: 0.10% to 2.00%; Mn: 0.10% to 2.00%; Cr: 0.10% to 1.20%; V: 0.010% to 0.200%; N: 0.0030% to 0.0200%; P?0.0250%; S?0.0250%; Mo: 0% to 0.50%, Co: 0% to 1.00%; B: 0% to 0.0050%; Cu: 0% to 1.00%; Ni: 0% to 1.00%; Nb: 0% to 0.0500%; Ti: 0% to 0.0500%; Mg: 0% to 0.0200%; Ca: 0% to 0.0200%; REM: 0% to 0.0500%; Zr: 0% to 0.0200%; Al: 0% to 1.00%; and a remainder consisting of Fe and impurities, in which a structure ranging from an outer surface of a head portion as an origin to a depth of 25 mm includes 95% or greater of a pearlite structure by area ratio, the hardness of the structure is in a range of Hv 360 to 500, and in ferrite of the pearlite structure at a position at a depth of 25 mm from the outer surface of the head portion as the origin, the number density of a V nitride having a grain size of 0.5 to 4.0 nm and including Cr is in a range of 1.0×1017 to 5.0×1017 cm?3.Type: ApplicationFiled: August 21, 2019Publication date: December 23, 2021Applicant: NIPPON STEEL CORPORATIONInventors: Masaharu UEDA, Jun TAKAHASHI, Teruhisa MIYAZAKI, Takuya TANAHASHI
-
Patent number: 10563357Abstract: A rail provided by the present invention includes: has a predetermined chemical components, wherein, in a region from a head surface constituted of a surface of a top head portion and a surface of a corner head portion to a depth of 10 mm, a total amount of pearlite structures and bainite structures is 95% by area or more, and an amount of the bainite structures is 20% by area or more and less than 50% by area, and an average hardness of the region from the head surface to a depth of 10 mm is in a range of Hv 400 to Hv 500.Type: GrantFiled: May 29, 2015Date of Patent: February 18, 2020Assignee: NIPPON STEEL CORPORATIONInventors: Masaharu Ueda, Teruhisa Miyazaki, Takuya Tanahashi
-
Patent number: 10494704Abstract: The present invention relates to a rail which has a predetermined chemical composition and satisfies expressions of 1.00<Mn/Cr?4.00 and 0.30?0.25×Mn+Cr?1.00 and in which a structure to a depth of 25 mm from an outer surface of a head portion as the origin includes 95% or greater of a pearlite structure, the hardness of the structure is in a range of Hv 350 to 480, 50 to 500 V carbonitride having an average grain size of 5 to 20 nm are present per 1.0 ?m2 of an area to be inspected in a transverse cross section at a position having a depth of 25 mm from the outer surface of the head portion, and the value obtained by subtracting the hardness of the position having the depth of 25 mm from the outer surface of the head portion from the hardness of the position having a depth of 2 mm from the outer surface of the head portion is in a range of Hv 0 to Hv 40.Type: GrantFiled: January 22, 2016Date of Patent: December 3, 2019Assignee: NIPPON STEEL CORPORATIONInventors: Masaharu Ueda, Takuya Tanahashi, Teruhisa Miyazaki
-
Patent number: 10233512Abstract: A rail provided by the present invention includes: has a predetermined chemical components, wherein a value of Mn/Cr, which is a ratio of Mn content with respect to Cr content, is within a range of 0.30 to 1.00, structures in a region from a head surface constituted of a surface of a top head portion and a surface of a corner head portion to a depth of 10 mm is 98% by area or more of bainite structures, and an average hardness of the region from the head surface to a depth of 10 mm is in a range of Hv 380 to Hv 500.Type: GrantFiled: May 29, 2015Date of Patent: March 19, 2019Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu Ueda, Teruhisa Miyazaki, Takuya Tanahashi
-
Publication number: 20170369975Abstract: The present invention relates to a rail which has a predetermined chemical composition and satisfies expressions of 1.00<Mn/Cr?4.00 and 0.30?0.25×Mn+Cr?1.00 and in which a structure to a depth of 25 mm from an outer surface of a head portion as the origin includes 95% or greater of a pearlite structure, the hardness of the structure is in a range of Hv 350 to 480, 50 to 500 V carbonitride having an average grain size of 5 to 20 nm are present per 1.0 ?m2 of an area to be inspected in a transverse cross section at a position having a depth of 25 mm from the outer surface of the head portion, and the value obtained by subtracting the hardness of the position having the depth of 25 mm from the outer surface of the head portion from the hardness of the position having a depth of 2 mm from the outer surface of the head portion is in a range of Hv 0 to Hv 40.Type: ApplicationFiled: January 22, 2016Publication date: December 28, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu UEDA, Takuya TANAHASHI, Teruhisa MIYAZAKI
-
Publication number: 20170051373Abstract: A rail provided by the present invention includes: has a predetermined chemical components, wherein, in a region from a head surface constituted of a surface of a top head portion and a surface of a corner head portion to a depth of 10 mm, a total amount of pearlite structures and bainite structures is 95% by area or more, and an amount of the bainite structures is 20% by area or more and less than 50% by area, and an average hardness of the region from the head surface to a depth of 10 mm is in a range of Hv 400 to Hv 500.Type: ApplicationFiled: May 29, 2015Publication date: February 23, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu UEDA, Teruhisa MIYAZAKI, Takuya TANAHASHI
-
Publication number: 20170044634Abstract: A rail provided by the present invention includes: has a predetermined chemical components, wherein a value of Mn/Cr, which is a ratio of Mn content with respect to Cr content, is within a range of 0.30 to 1.00, structures in a region from a head surface constituted of a surface of a top head portion and a surface of a corner head portion to a depth of 10 mm is 98% by area or more of bainite structures, and an average hardness of the region from the head surface to a depth of 10 mm is in a range of Hv 380 to Hv 500.Type: ApplicationFiled: May 29, 2015Publication date: February 16, 2017Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATIONInventors: Masaharu UEDA, Teruhisa MIYAZAKI, Takuya TANAHASHI
-
Patent number: 8980019Abstract: A steel rail includes: by mass %, higher than 0.85% to 1.20% of C; 0.05% to 2.00% of Si; 0.05% to 0.50% of Mn; 0.05% to 0.60% of Cr; P?0.0150%; and the balance consisting of Fe and inevitable impurities, wherein 97% or more of a head surface portion which is in a range from a surface of a head corner portion and a head top portion as a starting point to a depth of 10 mm has a pearlite structure, a Vickers hardness of the pearlite structure is Hv320 to 500, and a CMn/FMn value which is a value obtained by dividing CMn [at. %] that is a Mn concentration of a cementite phase in the pearlite structure by FMn [at. %] that is a Mn concentration of a ferrite phase is equal to or higher than 1.0 and equal to or less than 5.0.Type: GrantFiled: June 7, 2011Date of Patent: March 17, 2015Assignee: Nippon Steel & Sumitomo Metal CorporationInventors: Masaharu Ueda, Jun Takahashi, Akira Kobayashi, Takuya Tanahashi
-
Publication number: 20130065079Abstract: A steel rail includes: by mass %, higher than 0.85% to 1.20% of C; 0.05% to 2.00% of Si; 0.05% to 0.50% of Mn; 0.05% to 0.60% of Cr; P?0.0150%; and the balance consisting of Fe and inevitable impurities, wherein 97% or more of a head surface portion which is in a range from a surface of a head corner portion and a head top portion as a starting point to a depth of 10 mm has a pearlite structure, a Vickers hardness of the pearlite structure is Hv320 to 500, and a CMn/FMn value which is a value obtained by dividing CMn [at. %] that is a Mn concentration of a cementite phase in the pearlite structure by FMn [at. %] that is a Mn concentration of a ferrite phase is equal to or higher than 1.0 and equal to or less than 5.0.Type: ApplicationFiled: June 7, 2011Publication date: March 14, 2013Inventors: Masaharu Ueda, jun Takahashi, Akira Kobayashi, Takuya Tanahashi
-
Patent number: 8361246Abstract: A pearlite rail contains, by mass %, 0.65 to 1.20% of C; 0.05 to 2.00% of Si; 0.05 to 2.00% of Mn; and the balance composed of Fe and inevitable impurities, wherein at least part of the head portion and at least part of the bottom portion has a pearlite structure, and the surface hardness of a portion of the pearlite structure is in a range of Hv320 to Hv500 and a maximum surface roughness of a portion of the pearlite structure is less than or equal to 180 ?m.Type: GrantFiled: August 13, 2010Date of Patent: January 29, 2013Assignee: Nippon Steel CorporationInventors: Masaharu Ueda, Kyohei Sonoyama, Takuya Tanahashi, Teruhisa Miyazaki, Katsuya Iwano
-
Publication number: 20110226389Abstract: A pearlite rail contains, by mass %, 0.65 to 1.20% of C; 0.05 to 2.00% of Si; 0.05 to 2.00% of Mn; and the balance composed of Fe and inevitable impurities, wherein at least part of the head portion and at least part of the bottom portion has a pearlite structure, and the surface hardness of a portion of the pearlite structure is in a range of Hv320 to Hv500 and a maximum surface roughness of a portion of the pearlite structure is less than or equal to 180 ?m.Type: ApplicationFiled: August 13, 2010Publication date: September 22, 2011Applicant: NIPPON STEEL CORPORATIONInventors: Masaharu Ueda, Kyohei Sonoyama, Takuya Tanahashi, Teruhisa Miyazaki, Katsuya Iwano