公开(公告)号：EP2366812A4

公开(公告)日：2012-04-25

申请号：EP09833249

申请日：2009-04-22

Applicant: JFE STEEL CORP

Inventor： MAKIMIZU YOICHI ,  KAJIYAMA HIROSHI ,  FUJITA SAKAE ,  YOSHIMI NAOTO ,  TADA MASAHIKO ,  MASUOKA HIROYUKI ,  HOSHINO KATSUYA ,  NAGOSHI MASAYASU

IPC: C23C28/00 ,  C23C2/26 ,  C23C2/40 ,  C23C18/12 ,  C23C22/53

CPC classification number: C23C2/12 ,  C23C2/26 ,  C23C2/40 ,  C23C18/1216 ,  C23C18/1241 ,  C23C22/53 ,  C23C28/04

Abstract: A method for manufacturing a galvanized steel sheet, includes: galvanizing a steel sheet; bringing the surface of the steel sheet into contact with an aqueous solution containing zinc ion in the range of 5 to 100 g/l as the zinc ion concentration, having a pH of 4 to 6, and having a liquid temperature of 20 to 70°C, holding the steel sheet for 1 to 60 seconds; and then washing and drying the steel sheet. The solution containing zinc is preferably one containing zinc sulfate, for example. According to the method described above, a galvanized steel sheet having an oxide layer having an average thickness of 10 nm or more and mainly containing zinc formed on the surface of the steel sheet and having excellent press formability can be stably manufactured in a short time.

公开(公告)号：EP2518181A4

公开(公告)日：2017-07-26

申请号：EP10839628

申请日：2010-12-24

Applicant: JFE STEEL CORP

Inventor： MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU ,  MIYATA MAI ,  YOSHIMI NAOTO ,  HIRASAWA JUNICHIRO ,  OTSUKA SHINJI ,  NAGANO HIDEKI ,  HASEGAWA KOHEI

IPC: C23C22/78 ,  C21D1/52 ,  C21D1/76 ,  C21D6/00 ,  C21D8/04 ,  C21D9/46 ,  C21D9/48 ,  C21D9/56 ,  C22C38/00 ,  C22C38/60

CPC classification number: C21D1/74 ,  C21D1/52 ,  C21D1/76 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0457 ,  C21D9/46 ,  C21D9/48 ,  C21D9/561 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18 ,  C23C8/02 ,  C23C8/14 ,  C23C8/80 ,  C23C22/78 ,  C23G1/08 ,  C23G1/081

Abstract: A high-strength cold-rolled steel sheet having high chemical convertibility and a tensile strength of 590 MPa or more and a method for producing such a steel sheet are provided. The steel sheet contains, in terms of percent by mass, C: 0.05 to 0.3%, Si: 0.6 to 3.0%, Mn: 1.0 to 3.0%, P: 0.1% or less, S: 0.05% or less, Al: 0.01 to 1%, N: 0.01% or less, and the balance being Fe and unavoidable impurities. The coverage ratio of reduced iron on a steel sheet surface is 40% or more. In order to produce such a steel sheet, an oxidation treatment is performed after cold rolling. In the oxidation treatment, first heating is conducted on a steel sheet in an atmosphere with an oxygen concentration of 1000 ppm or more until the steel sheet temperature reaches 630°C or higher and then second heating is conducted on the steel sheet in an atmosphere with an oxygen concentration of less than 1000 ppm until the steel sheet temperature reaches 700°C or higher. Subsequently, annealing is conducted in a furnace in a 1 to 10 vol% H 2 + balance N 2 gas atmosphere with a dew point of -25°C or less.

Abstract translation: 提供化学转化处理性高，拉伸强度为590MPa以上的高强度冷轧钢板及其制造方法。 该钢板以质量％计含有C：0.05〜0.3％，Si：0.6〜3.0％，Mn：1.0〜3.0％，P：0.1％以下，S：0.05％以下，Al：0.01 至1％，N：0.01％或更少，其余为Fe和不可避免的杂质。 还原铁在钢板表面的覆盖率为40％以上。 为了制造这样的钢板，在冷轧后进行氧化处理。 在氧化处理中，首先在氧浓度为1000ppm以上的气氛中对钢板进行加热直至钢板温度达到630℃以上，然后在钢板 直到钢板温度达到700℃或更高时，氧浓度低于1000ppm。 接着，在露点为-25℃以下的1〜10体积％的H 2 +余量的N 2气体气氛的炉内进行退火。

公开(公告)号：EP3054025A4

公开(公告)日：2016-11-30

申请号：EP14871692

申请日：2014-12-16

Applicant: JFE STEEL CORP

Inventor： HASEGAWA HIROSHI ,  KANEKO SHINJIRO ,  MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU

IPC: C22C38/00 ,  C21D9/46 ,  C22C18/04 ,  C22C38/38 ,  C22C38/58 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D8/0278 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C18/04 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/36 ,  C23C2/40

Abstract: Provided are a high-strength galvanized steel sheet including a high-strength galvannealed steel sheet having a tensile strength (TS) of 1180 MPa or more and excellent spot weldability, anti-crash property, and bending formability which can preferably be used as a material for automobile parts and a method for manufacturing the steel sheet. The steel sheet has a C content of 0.15% or less, in which an area ratio of ferrite is 10% or less, an area ratio of bainitic ferrite is 2% or more and 30% or less, an area ratio of martensite is 60% or more and 98% or less, an area ratio of retained austenite is less than 2%, an average grain diameter of martensite adjacent to bainite is 15 µm or less, a proportion of massive martensite adjacent only to bainite to the whole metallographic structure is 10% or less, and a value (”Hv) calculated by subtracting the Vickers hardness at a position located at 20 µm from the surface of the steel sheet from the Vickers hardness at a position located at 100 µm from the surface of the steel sheet is 30 or more.

公开(公告)号：EP3050989A4

公开(公告)日：2016-10-19

申请号：EP14873009

申请日：2014-11-27

Applicant: JFE STEEL CORP

Inventor： HASEGAWA HIROSHI ,  KANEKO SHINJIRO ,  MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU

IPC: C22C38/00 ,  C21D8/02 ,  C21D9/46 ,  C22C18/00 ,  C22C18/04 ,  C22C38/38 ,  C22C38/58 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D8/0263 ,  C21D8/0278 ,  C21D2211/005 ,  C21D2211/008 ,  C22C18/04 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/285 ,  C23C2/36 ,  C23C2/40

Abstract: Provided are a high-strength steel sheet having a yield strength (YS) of 780 MPa or more, a tensile strength (TS) of 1180 MPa or more, excellent spot weldability, excellent ductility, and excellent bending workability, which is suitable as a material of automotive parts, and a method for producing the high-strength steel sheet. In the high-strength steel sheet, the C content is 0.15% or less, the area ratio of ferrite is 8% to 45%, the area ratio of martensite is 55% to 85%, the proportion of martensite grains adjacent to only ferrite grains in the entire microstructure is 15% or less, the average crystal grain sizes of ferrite and martensite are each 10 µm or less, and the area ratio of ferrite grains having a size of 10 µm or more to all the ferrite grains included in a portion of the steel sheet which extends from 20 to 100 µm below the surface thereof is less than 5%.

Abstract translation: 本发明提供一种屈服强度（YS）为780MPa以上，抗拉强度（TS）为1180MPa以上，点焊性，优异的延展性，优异的弯曲加工性的高强度钢板，其适合作为 汽车部件的材料，以及高强度钢板的制造方法。 在高强度钢板中，C含量为0.15％以下，铁素体的面积比为8〜45％，马氏体的面积比为55〜85％，仅与铁素体相邻的马氏体比例 整个微观结构的晶粒度为15％以下，铁素体和马氏体的平均结晶粒径分别为10μm以下，与包含在a的铁素体晶粒中的铁素体晶粒的面积比为10μm以上 从其表面下方的20〜100μm延伸的钢板的部分小于5％。

公开(公告)号：EP2840161A4

公开(公告)日：2015-04-29

申请号：EP12874412

申请日：2012-04-17

Applicant: JFE STEEL CORP

Inventor： MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU ,  MIYATA MAI

IPC: C23C2/02 ,  B32B15/01 ,  C21D1/76 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C23C2/06 ,  C23C2/28 ,  C23C8/18 ,  C23C8/80

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D1/76 ,  C21D9/561 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C23C2/02 ,  C23C2/12 ,  C23C8/14 ,  C23C8/80

Abstract: A method for manufacturing a galvannealed steel sheet having excellent coating adhesion and sliding property in which a steel sheet is subjected to an oxidation treatment and reduction annealing, the method including performing the oxidation treatment under conditions such that the steel sheet is heated up to a temperature of 600°C or higher in an atmosphere which contains 1000 ppm or more of O 2 and the balance consisting of N 2 , CO, CO 2 , H 2 O and inevitable impurities and then heated up to a temperature of 700°C or higher in an atmosphere which contains less than 1000 ppm of O 2 and the balance consisting of N 2 , CO, CO 2 , H 2 O and inevitable impurities and performing the reduction annealing in an atmosphere whose dewpoint is 5°C or higher and which contains 1 vol.% or more and 15 vol.% or less of H 2 and the balance consisting of N 2 and inevitable impurities.

公开(公告)号：EP3159420A4

公开(公告)日：2017-07-26

申请号：EP15839932

申请日：2015-08-20

Applicant: JFE STEEL CORP

Inventor： MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU ,  TAKAHASHI HIDEYUKI ,  TAKEDA GENTARO ,  FUJITA KOICHIRO

IPC: C21D9/46 ,  C22C38/00 ,  C22C38/04 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C21D8/0278 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/32 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C23F17/00

Abstract: The invention provides a method for producing high-strength galvanized steel sheets having excellent coating adhesion, workability and appearance. The method for producing high-strength galvanized steel sheets includes a hot rolling step of hot rolling a slab including, in mass%, C: 0.05 to 0.30%, Si: 0.1 to 2.0% and Mn: 1.0 to 4.0%, thereafter coiling the steel sheet into a coil at a specific temperature T C , and pickling the steel sheet, a cold rolling step of cold rolling the hot-rolled steel sheet resulting from the hot rolling step, an annealing step of annealing the cold-rolled steel sheet resulting from the cold rolling step under specific conditions, and a galvanizing step of galvanizing the annealed sheet resulting from the annealing step in a galvanizing bath containing 0.12 to 0.22 mass% Al.

Abstract translation: 本发明提供具有优异的涂层粘合性，可加工性和外观的高强度热镀锌钢板的制造方法。 本发明的高强度热镀锌钢板的制造方法包括：将以质量％计含有C：0.05〜0.30％，Si：0.1〜2.0％，Mn：1.0〜4.0％的钢坯进行热轧后， 在特定温度TC下将钢板卷取成卷材并进行酸洗，冷轧由热轧工序得到的热轧钢板的冷轧工序，对由该热轧工序得到的冷轧钢板进行退火的退火工序 在特定条件下进行的冷轧步骤以及在含有0.12〜0.22质量％Al的镀锌浴中对退火步骤得到的退火板进行镀锌的镀锌步骤。

公开(公告)号：EP3168321A4

公开(公告)日：2017-05-31

申请号：EP15818936

申请日：2015-06-05

Applicant: JFE STEEL CORP

Inventor： TAKEDA GENTARO ,  MIYAKE MASARU ,  MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU ,  SUZUKI YOSHIKAZU

IPC: C23C2/02 ,  C21D9/56 ,  C22C38/00 ,  C22C38/04 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C21D9/561 ,  C21D9/56 ,  C22C38/00 ,  C22C38/04 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: Provided is a method of producing a galvannealed steel sheet, the production method being capable of achieving a favorable plated appearance and of suppressing reductions in tensile strength. This method of producing a galvannealed steel sheet has: a step wherein a steel strip is transported through the inside of an annealing furnace, in order through a heating zone that includes a direct-firing-type furnace, a soaking zone, and a cooling zone, and the steel strip is annealed; a step wherein, after being discharged from the cooling zone, the steel strip is hot-dip galvanized; and a step wherein the zinc-plating applied to the steel strip is heated and alloyed. The production method is characterized in that a mixed gas that includes a humidified gas and a dry gas is supplied to the inside of the soaking zone from at least one gas supply port that is provided to the height-direction lower half of the soaking zone, and in that the dew point measured in the height-direction upper fifth of the soaking zone and the dew point measured in the height-direction lower fifth are both -20-0 °C.

Abstract translation: 提供一种合金化热浸镀锌钢板的制造方法，该制造方法能够实现良好的镀覆外观，抑制拉伸强度的降低。 该合金化热浸镀锌钢板的制造方法具有以下工序：将钢带依次通过由直烧型炉，均热带，冷却带构成的加热带在退火炉内输送 ，钢带退火; 从冷却区排出钢带后进行热浸镀锌的工序; 以及施加到钢带上的镀锌被加热并合金化的步骤。 该制造方法的特征在于，从设置于均热带的高度方向下半部的至少一个气体供给口向均热带的内部供给包含加湿气体和干燥气体的混合气体， 并且在均热带的高度方向上部五分之一处测量的露点和在高度方向五分之一处测量的露点都是-20℃〜0℃。

公开(公告)号：EP2865780A4

公开(公告)日：2015-04-29

申请号：EP13809989

申请日：2013-06-18

Applicant: JFE STEEL CORP

Inventor： MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU ,  NAGANO HIDEKI ,  NAGATAKI YASUNOBU

IPC: C23C2/06 ,  B32B15/01 ,  C21D1/26 ,  C21D8/04 ,  C21D9/46 ,  C21D9/48 ,  C22C18/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/38 ,  C22C38/58 ,  C23C2/28

CPC classification number: C23C2/06 ,  B32B15/013 ,  C21D1/26 ,  C21D8/0478 ,  C21D9/46 ,  C21D9/48 ,  C21D2251/00 ,  C22C18/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/38 ,  C23C2/28 ,  C23C2/40 ,  Y10T428/12799

Abstract: Provided is a galvannealed steel sheet with excellent anti-powdering property when press forming is performed, without controlling the contents of chemical elements in steel which are effective for strengthening a steel sheet, such as Si and P, to be low in order to achieve required material properties and without increasing cost due to, for example, processes being complicated. A galvannealed steel sheet with excellent anti-powdering property has a coated layer taking in grains of a base steel sheet such that the grains constitute 2.0% or more and 15.0% or less of the coated layer in terms of cross section area ratio.

公开(公告)号：EP2377968A4

公开(公告)日：2012-05-02

申请号：EP09833250

申请日：2009-04-22

Applicant: JFE STEEL CORP

Inventor： MAKIMIZU YOICHI ,  KAJIYAMA HIROSHI ,  FUJITA SAKAE ,  YOSHIMI NAOTO ,  TADA MASAHIKO ,  OOTSUKA SHINJI ,  MASUOKA HIROYUKI ,  HOSHINO KATSUYA

IPC: C23C28/00 ,  C23C2/26 ,  C23C18/12 ,  C23C22/53 ,  C23C22/60 ,  C23C22/68

CPC classification number: C23C2/12 ,  C23C2/26 ,  C23C2/40 ,  C23C18/1216 ,  C23C18/1241 ,  C23C22/53 ,  C23C22/60 ,  C23C22/68 ,  C23C28/04

Abstract: A method for producing a galvanized steel sheet includes contacting a steel sheet with a zinc-containing aqueous solution having a zinc ion concentration of 1 to 100 g/l, contacting the steel sheet with an aqueous solution with a pH of 6 to 14, washing the steel sheet with water, and then drying the steel sheet. An example of the zinc-containing aqueous solution is a solution containing zinc sulfate. According to the method, an oxide layer which has an average thickness of 10 nm or more and which principally contains zinc is formed on the steel sheet and the galvanized steel sheet can be stably produced at high speed in a reduced space so as to have excellent press formability.

公开(公告)号：EP3219822A4

公开(公告)日：2017-12-06

申请号：EP15877746

申请日：2015-11-24

Applicant: JFE STEEL CORP

Inventor： HASEGAWA HIROSHI ,  KIMURA HIDEYUKI ,  FUNAKAWA YOSHIMASA ,  MAKIMIZU YOICHI ,  SUZUKI YOSHITSUGU

IPC: C22C38/00 ,  C21D9/46 ,  C22C38/06 ,  C22C38/58 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

CPC classification number: C23C2/40 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/58 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28

Abstract: Disclosed are a high-strength galvanized steel sheet and a method for producing the same, the high-strength galvanized steel sheet including a chemical composition containing, by mass %, C: 0.15% or more and 0.25% or less, Si: 0.50% or more and 2.5% or less, Mn: 2.3% or more and 4.0% or less, P: 0.100% or less, S: 0.02% or less, Al: 0.01% or more and 2.5% or less, and the balance being Fe and inevitable impurities; and a steel-sheet microstructure containing, by an area percentage basis, a tempered martensite phase: 30% or more and 73% or less, a ferrite phase: 25% or more and 68% or less, a retained austenite phase: 2% or more and 20% or less, and other phases: 10% or less (including 0%), the other phases containing a martensite phase: 3% or less (including 0%) and a bainitic ferrite phase: less than 5% (including 0%), the tempered martensite phase having an average grain size of 8 µm or less, and the retained austenite phase having a C content less than 0.7% by mass.