公开(公告)号：US20200248290A1

公开(公告)日：2020-08-06

申请号：US16488701

申请日：2018-02-02

Applicant: JFE STEEL CORPORATION

Inventor： Naoki TAKAYAMA ,  Yusuke TERAZAWA ,  Yoshiaki MURAKAMI ,  Kazukuni HASE ,  Yusaku TAKEMURA ,  Yasuhiro MUROTA

IPC: C22C38/54 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/52 ,  C22C38/50 ,  C21D8/02 ,  C21D9/46

Abstract: Provided is an abrasion-resistant steel plate which has high hardness up to the mid-thickness part thereof although the steel plate is 50 mm or more, and can be manufactured at low cost. The abrasion-resistant steel plate has a specific chemical composition having DI* of 120 or more, where DI* is defined by the following Formula (1): DI*=33.85×(0.1×C)0.5×(0.7×Si+1)×(3.33×Mn+1)×(0.35×Cu+1)×(0.36×Ni+1)×(2.16×Cr+1)×(3×Mo+1)×(1.75×V+1)×(1.5×W+1) . . . (1), has HB1 of 360 HBW10/3000 to 490 HBW10/3000, HB1 being a Brinell hardness at a depth of 1 mm from a surface, has a hardness ratio, HB1/2 to HB1, of 75% or more, HB1/2 being a Brinell hardness at a mid-thickness position, and has a plate thickness of 50 mm or more.

公开(公告)号：US20230271270A1

公开(公告)日：2023-08-31

申请号：US18018140

申请日：2021-07-26

Applicant: JFE STEEL CORPORATION

Inventor： Naoaki MUNEMURA ,  Hiroshi MATSUDA ,  Yoshiaki MURAKAMI

IPC: B23K20/12

CPC classification number: B23K20/1255 ,  B23K2101/18

Abstract: An element, a friction element welding method, and a method for producing a friction element welded joint. The element is for performing friction element welding on a sheet stack of two or more stacked metal sheets by pressing the element into the sheet stack while the element is rotated. The element includes a circular columnar mandrel that is to enter the sheet stack, a circular collar disposed at an upper end portion of the mandrel, a first conical body extending from a lower end surface of the mandrel, and a second conical body disposed on the lower side of the first conical body. The vertical angle β of the second conical body and the vertical angle α of the first conical body satisfy the relation β

公开(公告)号：US20220402078A1

公开(公告)日：2022-12-22

申请号：US17772777

申请日：2020-10-29

Applicant: JFE STEEL CORPORATION

Inventor： Kyohei KONISHI ,  Chikaumi SAWANISHI ,  Hiroshi MATSUDA ,  Yoshiaki MURAKAMI

IPC: B23K35/02 ,  B23K35/30 ,  B23K9/173

Abstract: A MIG welding method for carbon steels using an Ar shielding gas. The method includes short-circuiting a welding wire and a base material. The average short-circuiting frequency in welding is 20 Hz to 300 Hz and the maximum short-circuiting period is 1.5 s or less.

公开(公告)号：US20190352749A1

公开(公告)日：2019-11-21

申请号：US16331303

申请日：2017-08-22

Applicant: JFE STEEL CORPORATION

Inventor： Koichi NAKASHIMA ,  Yoshiaki MURAKAMI ,  Kazukuni HASE

IPC: C22C38/04 ,  C22C38/00 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/02 ,  C21D8/02 ,  B23K35/30

Abstract: A steel material for high heat input welding used for low-temperature storage tanks, and has excellent joint strength and low-temperature toughness at −55° C. of a weld heat-affected zone when high heat input welding at a heat input exceeding 80 kJ/cm is performed. The steel material has a specified chemical composition in which Mn, Cu, and Ni are contained so as to satisfy: 1.85≤Mn+0.4×(Cu+Ni)≤2.10, where Mn, Cu, and Ni represent the contents, by mass%, of respective components or are set to zero if not contained.

公开(公告)号：US20240167492A1

公开(公告)日：2024-05-23

申请号：US18282898

申请日：2022-03-17

Applicant: JFE STEEL CORPORATION

Inventor： Naoaki MUNEMURA ,  Hiroshi MATSUDA ,  Yoshiaki MURAKAMI

IPC: F16B5/08 ,  B23K20/12 ,  F16B33/06 ,  F16B35/06

CPC classification number: F16B5/08 ,  B23K20/12 ,  F16B33/06 ,  F16B35/06

Abstract: A friction joining element for mechanically joining a sheet set prepared by stacking two or more metal sheets including a high strength steel sheet as an upper sheet. The friction joining element includes a mandrel having an overall length adjusted to be equal to or less than the total thickness of the sheet set, and a collar disposed at an upper portion of the mandrel. The friction joining element has a screw thread on a side surface of a head-side portion of the mandrel.

公开(公告)号：US20240149372A1

公开(公告)日：2024-05-09

申请号：US18282359

申请日：2022-03-22

Applicant: JFE STEEL CORPORATION

Inventor： Naoaki MUNEMURA ,  Yasuaki OKITA ,  Hiroshi MATSUDA ,  Yoshiaki MURAKAMI

IPC: B23K20/12

CPC classification number: B23K20/1255 ,  B23K20/125 ,  B23K20/129

Abstract: In performing friction element welding of a sheet set constituted by two or more metal sheets, an element is press penetrated into the sheet set. The element may include a round columnar mandrel; a disc-shaped collar provided at an upper end face of the mandrel; and a conical pin extending from a lower end face of the mandrel. The element has a plurality of fluidized-metal discharge grooves arranged spirally in a flat area of the lower end face of the mandrel, the flat area excluding the pin. Alternatively, the element may include a round columnar mandrel having a lower end face that forms a conical face with an apical angle αm, the conical face having one or more pairs of chippings discharge grooves or having a plurality of cutting edges, the chippings discharge grooves each extending in a curved manner from an apex of the conical face.

公开(公告)号：US20230132518A1

公开(公告)日：2023-05-04

申请号：US17917772

申请日：2021-03-18

Applicant: JFE STEEL CORPORATION

Inventor： Kyohei KONISHI ,  Chikaumi SAWANISHI ,  Hiroshi MATSUDA ,  Yoshiaki MURAKAMI

IPC: B23K9/173 ,  B23K9/09

Abstract: Provided are an arc welded joint and an arc welding method. The arc welded joint has a slag-coverage area ratio SRATIO (%) of 15% or less, and a weld bead width ratio WRATIO (%) of 60% or more. The SRATIO is calculated by using an equation SRATIO=100×SSLAG/SBEAD. In this equation, an area of a surface of a weld bead formed by performing arc welding on a steel sheet is defined as a weld bead surface area SBEAD (mm2) and, of the weld bead surface area SBEAD, an area of a region covered with slag is defined as a slag surface area SSLAG (mm2). The WRATIO is calculated by using an equation WRATIO=100×WMIN/WMAX from a maximum value WMAX (mm) and a minimum value WMIN (mm) of a weld bead width in a direction perpendicular to a welding line of the weld bead.

公开(公告)号：US20220333227A1

公开(公告)日：2022-10-20

申请号：US17753552

申请日：2020-08-17

Applicant: JFE STEEL CORPORATION

Inventor： Naoki TAKAYAMA ,  Shigeki KITSUYA ,  Yoshiaki MURAKAMI

IPC: C22C38/38 ,  C22C38/02 ,  C21D8/04

Abstract: The steel plate has a specific chemical composition, and a microstructure where a volume fraction of martensite at a depth of 1 mm from a surface of the steel plate is 95% or more, and at a depth of 1 mm from a surface of the steel plate, a Vickers hardness at 400° C. is 288 or more, and a Brinell hardness at 25° C. is 360 HBW10/3000 to 490 HBW10/3000.