公开(公告)号：US20190106762A1

公开(公告)日：2019-04-11

申请号：US16180508

申请日：2018-11-05

Applicant: JFE STEEL CORPORATION

Inventor： Kenji OKUSHIRO ,  Hiroyuki FUKUDA ,  Hideo KIJIMA ,  Moriyasu YAMAGUCHI

IPC: C21D9/04 ,  B21B45/02 ,  C21D1/18 ,  C21D6/00 ,  C21D1/667 ,  C21D1/62 ,  B21B1/085 ,  C21D1/56 ,  C22C38/00

Abstract: A rail-manufacturing method according to the present invention performs forced cooling on at least a head of a hot rail hot-rolled at or heated to the austenite region temperature or higher. The forced cooling is performed for 10 seconds from start of the forced cooling so that the cooling rate at the head surface becomes 1° C./s or higher to 20° C./s or lower, the forced cooling is performed after a lapse of 10 seconds from the start of the forced cooling until heat generation during transformation begins in the head surface so that the cooling rate at the head surface becomes 1° C./s or higher to 5° C./s or lower, the forced cooling is performed during transformation from beginning to end of the heat generation during transformation so that the cooling rate at the head surface becomes lower than 1° C./s or the temperature-rising rate becomes 5° C./s or lower, and the forced cooling is performed after the end of the heat generation during transformation until the rail-head surface temperature becomes 450° C. or lower so that the cooling rate at the head surface becomes 1° C./s or higher to 20° C./s or lower.

公开(公告)号：US20160040263A1

公开(公告)日：2016-02-11

申请号：US14770664

申请日：2014-03-25

Applicant: JFE STEEL CORPORATION

Inventor： Kenji OKUSHIRO ,  Hiroyuki FUKUDA ,  Hideo KIJIMA ,  Moriyasu YAMAGUCHI

IPC: C21D9/04 ,  C22C38/00 ,  C21D1/56 ,  C21D6/00 ,  C21D1/667 ,  C21D1/18

CPC classification number: C21D9/04 ,  B21B1/085 ,  B21B45/02 ,  B21B2045/0221 ,  C21D1/18 ,  C21D1/56 ,  C21D1/62 ,  C21D1/667 ,  C21D6/00 ,  C21D2211/009 ,  C22C38/00 ,  C22C38/50

Abstract: Rail manufacturing method performs, on at least a head of the rail that is hot after hot-rolled at an austenite region temperature or higher or after heated to the austenite region temperature or higher, forced cooling: for 10 seconds from start of the forced cooling so that a cooling rate at a surface of the head becomes 1° C./s to 20° C./s; during a period after a lapse of 10 seconds from the start until heat generation during transformation begins at the surface so that the cooling rate becomes 1° C./s to 5° C./s; during transformation from beginning to end of the heat generation during transformation so that the cooling rate becomes lower than 1° C./s or a temperature-rising rate becomes 5° C./s or lower; and during a period after the end of the heat generation during transformation until temperature at the surface becomes 450° C. or lower so that the cooling rate becomes 1° C./s to 20° C./s.

Abstract translation: 轨道制造方法在奥氏体区域以上的热轧后或加热到奥氏体区域温度以上之后，至少在热轧头部进行强制冷却：从强制冷却开始10秒钟 使得头部表面的冷却速度变为1℃/ 20℃/秒; 在从开始经过10秒之后的一段时间到在表面处的变换开始之前发热，从而使冷却速度变为1℃/ 5℃/ 5℃。 在转化期间从发热开始到结束的转变，使得冷却速度变得低于1℃/ s或升温速率变为5℃/ s以下; 并且在转化期间的热产生结束之后的一段时间内，直到表面的温度变为450℃或更低，使得冷却速率变为1℃/ 20℃/秒。

公开(公告)号：US20170233843A1

公开(公告)日：2017-08-17

申请号：US15503361

申请日：2015-08-19

Applicant: JFE STEEL CORPORATION

Inventor： Hideo KIJIMA ,  Hiroyuki FUKUDA ,  Kenji OKUSHIRO

IPC: C21D9/00 ,  E01B5/02 ,  C22C38/04 ,  C22C38/02 ,  C21D9/04 ,  C22C38/24

Abstract: A manufacturing method and a manufacturing apparatus for a head hardened rail to which various alloy elements are added and which is excellent in hardness and toughness of a head portion surface layer. The method includes, when forcibly cooling at least a head portion of a hot-rolled rail or a heated rail, starting the forcible cooling from a state where a surface temperature of the head portion of the rail is not less than an austenite range temperature, and performing the forcible cooling at a cooling rate of 10° C./sec or more until the surface temperature reaches 500° C. or more and 700° C. or less after the forcible cooling is started.

公开(公告)号：US20220307101A1

公开(公告)日：2022-09-29

申请号：US17596437

申请日：2020-06-09

Applicant: JFE STEEL CORPORATION

Inventor： Kenji OKUSHIRO ,  Kazuya TOKUNAGA ,  Moriyasu YAMAGUCHI

IPC: C21D8/06 ,  C22C38/18 ,  C22C38/04 ,  C22C38/02 ,  C21D11/00

Abstract: A rail comprises a predetermined chemical composition. In a hardness distribution in a region from a rail head surface to a depth of 16.0 mm, a part having higher hardness than V1 that is minimum hardness in a first internal region is present in a second internal region, and hardness of the rail head surface is HBW 400 to 520 and average hardness in the region from the rail head surface to the depth of 16.0 mm is HBW 350 or more.

公开(公告)号：US20170283895A1

公开(公告)日：2017-10-05

申请号：US15511431

申请日：2015-09-10

Applicant: JFE STEEL CORPORATION

Inventor： Kenji OKUSHIRO ,  Hideo KIJIMA ,  Hiroyuki FUKUDA ,  Moriyasu YAMAGUCHI

IPC: C21D9/04 ,  C21D8/00 ,  C22C38/50 ,  C22C38/44 ,  C22C38/42 ,  C22C38/60 ,  C22C38/24 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B21B1/085 ,  C22C38/26

CPC classification number: C21D9/04 ,  B21B1/085 ,  C21D8/00 ,  C21D8/005 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/24 ,  C22C38/26 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/60

Abstract: A method and an apparatus for manufacturing a rail having high ductility in both a head portion and a foot portion. A heated steel rail material is hot-rolled, the temperature is adjusted by cooling the hot-rolled steel rail material, the steel rail material subjected to the temperature adjustment is processed into a rail shape by means of temperature-adjusted rolling at an area reduction ratio of 20% or more, and, in adjusting the temperature of the steel rail material, the surface portions of the steel rail material corresponding to a head portion and a foot portion of the rail shape so that the temperatures of the surface portions reach 500° C. or more and 1,000° C. or less.