公开(公告)号：US20190256957A1

公开(公告)日：2019-08-22

申请号：US16329463

申请日：2016-09-28

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Manabu KUBOTA ,  Akira SHIGA ,  Hajime HASEGAWA

IPC: C22C38/54 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/50 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28

Abstract: A steel according to an aspect of the present invention includes, as a chemical composition, by unit mass %, C: 0.15% to 0.40%, Mn: 0.10% to 1.50%, S: 0.002% to 0.020%, Ti: 0.005% to 0.050%, B: 0.0005% to 0.0050%, Bi: 0.0010% to 0.0100%, P: 0.020% or less, N: 0.0100% or less, Si: 0% or more and less than 0.30%, Cr: 0% to 1.50%, Al: 0% to 0.050%, Mo: 0% to 0.20%, Cu: 0% to 0.20%, Ni: 0% to 0.20%, Nb: 0% to 0.030%, and a remainder including Fe and impurities.

公开(公告)号：US20160060744A1

公开(公告)日：2016-03-03

申请号：US14783292

申请日：2014-04-16

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Manabu KUBOTA ,  Shuji KOZAWA

IPC: C23C8/22 ,  C21D6/00 ,  C22C38/60 ,  C22C38/50 ,  C22C38/44 ,  C22C38/42 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23C8/32

CPC classification number: C23C8/22 ,  B22D11/00 ,  C21C7/10 ,  C21D1/06 ,  C21D1/32 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D7/02 ,  C21D8/06 ,  C21D2211/004 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/44 ,  C22C38/50 ,  C22C38/60 ,  C23C8/32

Abstract: There is provided a case-hardening steel in which in inclusion evaluation using an extreme value statistical method, when an estimated area S is 30,000 mm2, an estimated value of the maximum size (√area)S of sulfide-based inclusions present in the estimated area S is 49 μm or less and an estimated value of the maximum size (√area)Ox of oxide-based inclusions present in the estimated area S is 80 μm or less, and the number of sulfide-based inclusions having a length of more than 20 μm and a thickness of more than 2 μm per 1 mm2 is limited to 200 or less,

Abstract translation: 提供了一种表面硬化钢，其中使用极值统计方法进行包含评价时，当估计面积S为30,000mm 2时，估计出的硫化物系夹杂物的最大尺寸（√area）S的估计值 面积S为49μm以下，估计面积S中存在的氧化物系夹杂物的最大尺寸（√area）Ox的估计值为80μm以下，长度多的硫化物系夹杂物的数量 超过20μm，每1mm 2大于2μm的厚度限制在200以下，

公开(公告)号：US20180094345A1

公开(公告)日：2018-04-05

申请号：US15554667

申请日：2016-03-31

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Tatsuya KOYAMA ,  Manabu KUBOTA

IPC: C22C38/60 ,  C22C38/58 ,  C22C38/54 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/34 ,  C22C38/00 ,  C21D1/06 ,  C23C8/22

CPC classification number: C22C38/60 ,  C21D1/06 ,  C21D1/76 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/26 ,  C22C38/28 ,  C22C38/34 ,  C22C38/38 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/52 ,  C22C38/54 ,  C22C38/58 ,  C23C8/22 ,  F16H55/06

Abstract: A case-hardened steel component includes a base metal and a carburized layer, the base metal has a predetermined chemical composition, a number density of Ti-based precipitates having an equivalent circle diameter of 5 to 50 nm in a surface region from a surface to a depth of 0.1 mm is 0.5 pieces/μm2 or more, and in the surface region, a number density of AlN having an equivalent circle diameter of 50 nm or more and 100 nm or less is 0.5 pieces/μm2 or less.

公开(公告)号：US20190078171A1

公开(公告)日：2019-03-14

申请号：US16076658

申请日：2017-03-08

Applicant: AISIN AW CO., LTD. ,  NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Koji OBAYASHI ,  Kazuaki OKADA ,  Keisuke MATSUZAKA ,  Masashi SAKAKIBARA ,  Manabu KUBOTA ,  Kei MIYANISHI ,  Tatsuya KOYAMA

IPC: C21D1/10 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  C22C38/22 ,  C22C38/32 ,  C22C38/26 ,  C22C38/28 ,  C22C38/24 ,  C22C38/34 ,  C21D1/18 ,  C21D7/06

Abstract: In this steel component, the concentration of C in a surface layer is 0.85 mass % or more to 1.2 mass % or less, which is higher than the concentration of C in a starting material steel, the surface layer has a volume ratio of a retained-austenite structure higher than 0% and lower than 10%, the remainder of the surface layer is a martensitic structure, the area fraction of grain boundary carbides in the surface layer is lower than 2%, a layer inside the surface layer is higher than the surface layer in a volume ratio of a retained-austenite structure, and in the layer inside the surface layer, the remainder is a martensitic structure.

公开(公告)号：US20180355455A1

公开(公告)日：2018-12-13

申请号：US15562321

申请日：2016-03-31

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Akira SHIGA ,  Manabu KUBOTA ,  Hajime HASEGAWA

IPC: C21D9/52 ,  C21D8/06 ,  C21D6/00 ,  C22C38/28 ,  C22C38/22 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B21B1/16

CPC classification number: C21D9/525 ,  B21B1/16 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/06 ,  C21D8/065 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/009 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/26 ,  C22C38/28 ,  C22C38/42 ,  C22C38/50

Abstract: The present invention adopts a hot rolled bar or hot rolled wire rod including a chemical composition including, by mass %, C: 0.05 to 0.30%, Si: 0.30 to 0.60%, Mn: 0.40 to 1.0%, S: 0.008 to less than 0.040%, Cr: 1.60 to 2.00%, Mo: 0.1% or less, Al: 0.025 to 0.05%, N: 0.010 to 0.025%, Ti: 0.003% or less, Bi: 0.0001 to 0.0050%, and a remainder including Fe and impurities, in which amounts of P and O in the impurities are respectively P: 0.025% or less and O: 0.002% or less; in which a microstructure includes ferrite-pearlite or ferrite-pearlite-bainite, and an Expression (1) is satisfied. 1.70≤Cr+2×Mo≤2.10  (1)

公开(公告)号：US20180347025A1

公开(公告)日：2018-12-06

申请号：US15778153

申请日：2016-11-25

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Akira SHIGA ,  Hajime HASEGAWA ,  Manabu KUBOTA ,  Hideo MIZUKAMI

IPC: C23C8/22 ,  C23C8/32 ,  C23C8/80 ,  C21D9/32 ,  C21D9/28 ,  C21D8/00 ,  C21D1/06 ,  C22C38/54 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

CPC classification number: C21D1/06 ,  C21D8/06 ,  C21D9/28 ,  C21D9/32 ,  C22C38/00 ,  C22C38/60 ,  C23C8/22 ,  C23C8/80

Abstract: A steel according to an aspect of the present invention has a chemical composition within a predetermined range, in which a hardenability index Ceq ranges from greater than 7.5 to smaller than 44.0, an AlN precipitation index IAlN ranges from greater than 0.00030 to smaller than 0.00110, a metallographic structure includes ferrite ranging from 85 to 100 area %, an average distance between sulfides, which are observed in a cross section parallel to a rolling direction of the steel and have an equivalent circle diameter ranging from 1 μm or greater to smaller than 2 μm, is shorter than 30.0 μm, and a presence density of the sulfides, which are observed in the cross section parallel to the rolling direction of the steel and have an equivalent circle diameter ranging from 1 μm or greater to smaller than 2 μm, is 300 pieces/mm2 or more.

公开(公告)号：US20160298224A1

公开(公告)日：2016-10-13

申请号：US15102581

申请日：2014-12-24

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Tatsuya KOYAMA ,  Manabu KUBOTA

IPC: C23C8/22 ,  C21D1/76 ,  C21D9/32 ,  C21D9/40 ,  C21D1/06

CPC classification number: C23C8/22 ,  C21D1/06 ,  C21D1/74 ,  C21D1/76 ,  C21D9/32 ,  C21D9/40 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/30 ,  C22C38/32 ,  C22C38/34 ,  C22C38/40 ,  C22C38/42 ,  C22C38/44 ,  C22C38/60 ,  C23C8/02

Abstract: A production method of a carburized steel, which improves a gas carburizing property of a steel having a high Si content and suppresss deterioration of productivity, includes preliminary and main gas carburizing processes. In the preliminary gas carburizing process, a steel having a chemical composition that contains C, Si, Mn, and Cr and, in mass %, satisfies Formula (1) is subjected to a gas carburizing treatment at a carburizing temperature Tp° C. that satisfies Formula (A) for 10 minutes to less than 20 hours. In the main gas carburizing process, a gas carburizing treatment is performed at a carburizing temperature Tr(° C.) that satisfies Formula (B) for a carburizing time tr minutes. 6.5

Abstract translation: 其中，在预浸渗过程中，在碳化过程中碳的配方中的碳被替代。

公开(公告)号：US20180371603A1

公开(公告)日：2018-12-27

申请号：US15777746

申请日：2016-11-25

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Akira SHIGA ,  Manabu KUBOTA ,  Hajime HASEGAWA ,  Hideo MIZUKAMI

IPC: C23C8/32 ,  C23C8/22 ,  C21D1/06 ,  C21D9/28 ,  C21D8/06 ,  C21D9/32 ,  C22C38/54 ,  C22C38/50 ,  C22C38/44 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

CPC classification number: C23C8/32 ,  C21D1/06 ,  C21D8/06 ,  C21D9/28 ,  C21D9/32 ,  C21D2211/005 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/44 ,  C22C38/50 ,  C22C38/54 ,  C22C38/60 ,  C23C8/02 ,  C23C8/22 ,  C23C8/80

Abstract: A steel according to an aspect of the present invention has a chemical composition within a predetermined range, in which a hardenability index Ceq ranges from greater than 7.5 to smaller than 44.0, a metallographic structure includes ferrite ranging from 85 to 100 area %, an average distance between sulfides, which are observed in a cross section parallel to a rolling direction of the steel and have an equivalent circle diameter ranging from 1 μm or greater to smaller than 2 μm, is shorter than 30.0 μm, and a presence density of the sulfides, which are observed in the cross section parallel to the rolling direction of the steel and have an equivalent circle diameter ranging from 1 μm or greater to smaller than 2 μm, is 300 pieces/mm2 or more.

公开(公告)号：US20180291485A1

公开(公告)日：2018-10-11

申请号：US15766764

申请日：2016-10-19

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Suguru YOSHIDA ,  Shinya TERAMOTO ,  Akira SHIGA ,  Manabu KUBOTA ,  Hajime HASEGAWA ,  Hideo MIZUKAMI

IPC: C22C38/60 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/02 ,  C22C38/04 ,  C22C38/00 ,  C21D8/02

CPC classification number: C22C38/60 ,  C21C7/0006 ,  C21C7/10 ,  C21D8/00 ,  C21D8/0226 ,  C21D2211/005 ,  C21D2211/009 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28

Abstract: There is a hot-rolled steel according to one aspect of the invention including predetermined chemical compositions including 0.0001 to 0.0050 mass % of Bi, in which 90 area % or more of a metallographic structure is configured with a ferrite and a pearlite, and an average number density of Mn sulfides extending along a rolling direction and having an aspect ratio exceeding 10 and equal to or smaller than 30, which is measured on a cross section parallel to the rolling direction, is 50 to 200 number/mm2.

公开(公告)号：US20180142333A1

公开(公告)日：2018-05-24

申请号：US15573076

申请日：2016-05-13

Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION

Inventor： Takahisa SUZUKI ,  Manabu KUBOTA ,  Shuji KOZAWA ,  Hirotsugu MIYAMOTO

IPC: C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/34 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00

Abstract: Spring steel includes: as a chemical composition, by mass %, C: 0.40% to 0.60%, Si: 0.90% to 2.50%, Mn: 0.20% to 1.20%, Cr: 0.15% to 2.00%, Ni: 0.10% to 1.00%, Ti: 0.030% to 0.100%, B: 0.0010% to 0.0060%, N: 0.0010% to 0.0070%, Cu: 0% to 0.50%, Mo: 0% to 1.00%, V: 0% to 0.50%, Nb: 0% to 0.10%, P: limited to less than 0.020%, S: limited to less than 0.020%, Al: limited to less than 0.050%, and a remainder including Fe and impurities, in a case where [Ti] represents a Ti content and [N] represents a N content by mass %, the chemical composition satisfies ([Ti]-3.43×[N])>0.03, and a total number density of a Ti carbide and a Ti carbonitride having a diameter of 5 nm to 100 nm is more than 50 piece/μm3.