公开(公告)号：US20170159693A1

公开(公告)日：2017-06-08

申请号：US15038764

申请日：2014-11-27

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Yosuke MATSUMOTO ,  Masamichi CHIBA

IPC分类号： F16B33/06 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B21K1/46

CPC分类号： F16B33/06 ,  B21K1/46 ,  C21D8/06 ,  C21D8/065 ,  C21D9/00 ,  C21D9/0093 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/18 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  F16B35/00

摘要： Provided are a high-strength bolt having a tensile strength of 1,000 to 1,400 MPa and exhibits the same level of the delayed fracture resistance as that of the standard alloy steel even when omitting or reducing Mo and Cr from the SCM steel and the SCr steel, a steel wire for bolts used to manufacture such a high-strength bolt, and useful methods for manufacturing them. The steel wire for bolts in the present invention satisfies the predetermined chemical composition. When a rate of a B content at D0/4 part in the steel wire for bolts is 100% where D0 is a diameter of the steel wire for bolts, a ratio of a B content at a surface of the steel wire for bolts is 75% or less on average, and a difference between a maximum value and a minimum value of the ratio is 25% or less. A prior austenite crystal grain size number in a region from the surface to a depth of 100 μm of the steel wire for bolts is No. 8 or more.

公开(公告)号：US20170219000A1

公开(公告)日：2017-08-03

申请号：US15515064

申请日：2015-09-08

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Yosuke MATSUMOTO ,  Masamichi CHIBA

IPC分类号： F16B33/00 ,  C21D8/06 ,  C21D1/32 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/00

CPC分类号： F16B33/008 ,  C21D1/32 ,  C21D8/06 ,  C21D8/065 ,  C21D9/00 ,  C21D9/0093 ,  C21D2211/001 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  F16B35/00

摘要： To provide a steel for bolts with excellent delayed fracture resistance and cold forgeability while maintaining the strength as a steel material, and also to provide a bolt producing from such a steel for bolts.The steel for bolts according to the present invention includes, in percent by mass: 0.20 to 0.40% of C; 1.5 to 2.5% of Si; 0.20 to 1.5% of Mn; more than 0% and 0.03% or less of P; more than 0% and 0.03% or less of S; 0.05 to 1.5% of Cr; 0.01 to 0.10% of Al; 0.0003 to 0.01% of B; 0.002 to 0.020% of N; and one or two elements selected from the group consisting of 0.02 to 0.10% of Ti and 0.02 to 0.10% of Nb, with the balance being iron and inevitable impurities.

公开(公告)号：US20160230260A1

公开(公告)日：2016-08-11

申请号：US15022857

申请日：2014-09-16

申请人： KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)

发明人： Yosuke MATSUMOTO ,  Atsushi INADA ,  Masamichi CHIBA ,  Yoshimasa URESHINO ,  Reiko KATO

IPC分类号： C22C38/50 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C21D1/18 ,  C22C38/02 ,  C22C38/00 ,  F16B31/06 ,  C21D9/00 ,  C21D6/00 ,  C22C38/46 ,  C22C38/04

CPC分类号： C22C38/50 ,  C21D1/18 ,  C21D1/25 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D9/0093 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  F16B31/06

摘要： To provide a steel for high-strength bolts, which can exhibit the sufficient delayed fracture resistance under the severe environment, and also has excellent bolt formability. The steel for high-strength bolts of the present invention includes C: 0.10 to 0.30%; and Ni: 0.4 to 0.7%, with the chemical composition being appropriately adjust, and satisfies the following formulas (1) and (2): 0.85≦[C]+[Si]/7+[Mn]/5+[Ni]/20+[Cr]/9+[Mo]/2≦1.3  (1) [C]−(0.07×[Mo]+0.20×[V])≦0.20  (2)

摘要翻译： 为了提供一种高强度螺栓用钢，能够在恶劣的环境下表现出足够的延迟断裂性，并且还具有优异的螺栓成形性。 本发明的高强度螺栓用钢包含C：0.10〜0.30％， 和Ni：0.4〜0.7％，化学成分适当调整，满足下式（1）和（2）：0.85≤[C] + [Si] / 7 + [Mn] / 5 + [Ni] /20+ [Cr] / 9+ [摩尔数]2≤1.3（1）[C] - （0.07×[Mo] + 0.20×[V]）≤0.20（2）

公开(公告)号：US20220106670A1

公开(公告)日：2022-04-07

申请号：US17426412

申请日：2020-01-14

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Koji YAMASHITA ,  Shogo MURAKAMI ,  Masayuki SAKATA ,  Masamichi CHIBA

IPC分类号： C22C38/22 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/42 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/06 ,  C21D8/06

摘要： Disclosed is a mechanical structure steel for cold-working, including: C: 0.32 to 0.44% by mass, Si: 0.15 to 0.35% by mass, Mn: 0.55 to 0.95% by mass, P: 0.030% by mass or less, S: 0.030% by mass or less, Cr: 0.85 to 1.25% by mass, Mo: 0.15 to 0.35% by mass, and Al: 0.01 to 0.1% by mass, with the balance consisting of iron and inevitable impurities, wherein an area ratio of proeutectoid ferrite is 30% or more and 70% or less, and an average grain size of ferrite crystal grains is 5 to 15 μm.

公开(公告)号：US20180066344A1

公开(公告)日：2018-03-08

申请号：US15561530

申请日：2016-03-14

申请人： KABUSHIKI KAISHA KOBE SEIKO SHO(KOBE STEEL, LTD.)

发明人： Yosuke MATSUMOTO ,  Masamichi CHIBA

IPC分类号： C22C38/50 ,  C21D9/00 ,  F16B33/00 ,  F16B33/06

CPC分类号： C22C38/50 ,  C21D8/06 ,  C21D9/0093 ,  C22C38/00 ,  C22C38/18 ,  F16B33/008 ,  F16B33/06 ,  F16B35/00

摘要： To provide a wire rod for bolts that has excellent acid pickling properties and the resistance to delayed fracture after quenching and tempering, and a bolt using the same. Disclosed is a wire rod for bolts that has excellent acid pickling properties and resistance to delayed fracture, including, in percent by mass: C: 0.3 to 0.6%; Si: 1.0 to 3.0%; Mn: 0.1 to 1.5%; P: more than 0% and 0.020% or less; S: more than 0% and 0.020% or less; Cr: 0.3 to 1.5%; Al: 0.02 to 0.10%; and N: 0.001 to 0.020%, with the balance being iron and inevitable impurities, wherein in a d× 1/4 position of the wire rod, where d is a diameter of the wire rod, a ferrite area ratio is in a range of 10 to 40%, with the remaining microstructure being bainite, pearlite and an inevitably formed microstructure, and a C content in a position at a depth of 0.1 mm from a surface layer of the wire rod is in a range of 50 to 100% of a C content in a base material.

公开(公告)号：US20180251876A1

公开(公告)日：2018-09-06

申请号：US15754364

申请日：2016-08-12

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Yuki SASAKI ,  Takuya KOCHI ,  Masamichi CHIBA ,  Masayuki SAKATA ,  Shogo MURAKAMI

IPC分类号： C22C38/60 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C22C38/14 ,  C21D8/06

CPC分类号： C22C38/60 ,  C21D1/18 ,  C21D1/32 ,  C21D8/06 ,  C21D8/065 ,  C21D2211/005 ,  C21D2211/009 ,  C21D2261/00 ,  C22C38/00 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14

摘要： Disclosed herein is a mechanical structure steel for cold-working that includes C, Si, Mn, P, S, Al, and N and has a metal microstructure including proeutectoid ferrite and pearlite, in which a total area ratio of the proeutectoid ferrite and the pearlite with respect to the entire microstructure is 90% or more, while an area ratio Af of the proeutectoid ferrite with respect to the entire microstructure satisfies a relationship of Af≥A where an A value is represented by formula (1) below, an average circle equivalent diameter of a bcc-Fe crystal grain is in a range of 15 to 30 μm, and a pearlite lamellar spacing is 0.20 μm or less on average: A=(103−128×[C(%)])×0.80(%)  (1) where [C (%)] in the formula (1) indicates the C content in percent by mass.

公开(公告)号：US20180105894A1

公开(公告)日：2018-04-19

申请号：US15562631

申请日：2016-03-16

申请人： Kabushiki Kaisha Kobe Seiko Sho {Kobe Steel, Ltd.)

发明人： Yuki SASAKI ,  Takuya KOCHI ,  Masamichi CHIBA ,  Masayuki SAKATA

IPC分类号： C21D9/52 ,  C22C38/40 ,  C22C38/32 ,  C22C38/20 ,  C22C38/12 ,  C22C38/08 ,  C22C38/18 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D1/32 ,  C21D8/06 ,  C21D6/00

CPC分类号： C21D9/525 ,  C21D1/32 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/06 ,  C21D8/065 ,  C21D2211/003 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/18 ,  C22C38/20 ,  C22C38/32 ,  C22C38/40 ,  C22C38/60

摘要： An object of the present invention is to provide a steel wire for mechanical structural parts that is reduced in deformation resistance and improved in crack resistance during cold working, and thus exhibits excellent cold workability. The steel wire for mechanical structural parts of the present invention is a steel wire containing, in mass %, 0.3 to 0.6% of C, (105 to 0.5% of Si, 0.2 to 1.7% of Mn, more than 0% and 0.03% or less of P, 0.001 to 0.05% of S, 0.005 to 0.1% of Al, and 0 to 0.015% of N, the balance being iron and inevitable impurities, wherein steel of the steel wire has a metal structure formed of ferrite and cementite, and the number proportion of cementite particles present in ferrite grain boundaries is 40% or more based on the total number of cementite particles.

公开(公告)号：US20170162306A1

公开(公告)日：2017-06-08

申请号：US15038756

申请日：2014-11-20

申请人： KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)

发明人： Kei MASUMOTO ,  Masamichi CHIBA

IPC分类号： H01F1/147 ,  C22C38/34 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C21D1/18 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/00 ,  C21D8/00 ,  C22C38/60 ,  C22C38/14

CPC分类号： H01F1/147 ,  C21D1/18 ,  C21D1/19 ,  C21D1/26 ,  C21D8/005 ,  C21D8/1244 ,  C21D8/1261 ,  C21D9/0068 ,  C21D2211/004 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/34 ,  C22C38/60 ,  H01F1/16

摘要： An object of the present invention to provide a soft magnetic steel that improves the magnetic properties, that is, the soft magnetic properties, the cold forgeability, and the magnetic aging characteristics without adding a large amount of alloy elements. The present invention is directed to a soft magnetic steel, including C, Mn, P, S, Al, and N in each predetermined amount, in which an area ratio of carbides and carbonitrides that have a thickness of less than 0.4 μm is 0.20 area % or less, and an area ratio M of carbides and carbonitrides that have a thickness of 0.4 μm or more in terms of percentage satisfies a relationship represented by the formula (1) below: F=M−20×[C]>0  (1) where [C] means a C content in the steel in percentage by mass.

公开(公告)号：US20170130295A1

公开(公告)日：2017-05-11

申请号：US15319115

申请日：2015-06-08

申请人： KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)

发明人： Yuki SASAKI ,  Takehiro TSUCHIDA ,  Takuya KOCHI ,  Koji YAMASHITA ,  Masamichi CHIBA ,  Kei MASUMOTO ,  Masayuki SAKATA

IPC分类号： C21D9/52 ,  C21D8/06 ,  C21D6/00 ,  C22C38/20 ,  C22C38/00 ,  C22C38/08 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  B21B1/22 ,  C22C38/16

CPC分类号： C21D9/525 ,  B21B1/22 ,  B21B2001/225 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/06 ,  C21D8/065 ,  C21D2211/005 ,  C21D2211/009 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/16 ,  C22C38/18 ,  C22C38/20

摘要： Provided is a steel for a mechanical structure for cold working, which contains C, Si, Mn, P, S, Al and N and in which the metal structure includes pearlite and ferrite, the total areal proportion of pearlite and ferrite relative to the overall structure is 90% or higher, the average circle-equivalent diameter of bcc-Fe crystal grains surrounded by large angle grain boundaries is 5-15 μm, the average aspect ratio of pro-eutectoid ferrite crystal grains is 3.0 or lower, and the average spacing at the narrowest pearlite lamellar spacing is 0.20 μm or less.