EP0462380B1 - Verfahren zum Herstellen bearbeitbarer, hochfester, kaltgewalzter Stahlbleche - Google Patents

Verfahren zum Herstellen bearbeitbarer, hochfester, kaltgewalzter Stahlbleche Download PDF

Info

Publication number
EP0462380B1
EP0462380B1 EP91106841A EP91106841A EP0462380B1 EP 0462380 B1 EP0462380 B1 EP 0462380B1 EP 91106841 A EP91106841 A EP 91106841A EP 91106841 A EP91106841 A EP 91106841A EP 0462380 B1 EP0462380 B1 EP 0462380B1
Authority
EP
European Patent Office
Prior art keywords
steel
rolling
cold
content
less
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP91106841A
Other languages
English (en)
French (fr)
Other versions
EP0462380A2 (de
EP0462380A3 (en
Inventor
Susumu c/o Technical Research Division Okada
Tojiro c/o Chiba Works Ikeda
Susumu C/O Technical Research Division Satoh
Hideo C/O Technical Research Division Abe
Jun-ichi c/o Chiba Works Mano
Norio c/o Mizushima Works Kawasaki Steel Ohta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
Kawasaki Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kawasaki Steel Corp filed Critical Kawasaki Steel Corp
Publication of EP0462380A2 publication Critical patent/EP0462380A2/de
Publication of EP0462380A3 publication Critical patent/EP0462380A3/en
Application granted granted Critical
Publication of EP0462380B1 publication Critical patent/EP0462380B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0431—Warm rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/04—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing
    • C21D8/0421—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips to produce plates or strips for deep-drawing characterised by the working steps
    • C21D8/0436—Cold rolling

Definitions

  • the present invention relates to a method of producing a high-strength cold-rolled steel sheet suitable for various types of working such as press working, bulging and so forth and adaptable also to deep drawing.
  • high-strength cold-rolled steel sheets are used not only for the inner panels but also for outer panels such as engine hoods, trunk lid and fenders. As a consequence, high-strength cold-rolled steel sheet is required to have an excellent workability.
  • Japanese Patent Laid-Open Publication No. 63-317648 discloses a cold-rolled steel sheet in which Ti, Nb and B are added to a low-carbon steel for the purpose of improving press-workability and spot-weldability. It has also been proposed to add strengthening elements such as P and Mn to the above-mentioned steel system. For instance, Japanese Patent Publication No.
  • 61-11294 discloses a method of producing a high-strength steel sheet having a superior workability in which a steel enriched with P is continuously annealed after a cold rolling.
  • Japanese patent Publication No. 1-28817 discloses a method in which a steel enriched with P and Mn is continuously annealed to form a high-strength cold-rolled steel sheet.
  • An object of the present invention is to provide a method of producing, from a low-carbon steel having an extremely small carbon content, a high-strength cold-rolled steel sheet suitable for working, and more particularly a steel sheet having a superior workability, specifically a Lankford value ( r ⁇ ) of 1.8 or greater, a tensile strength T.S.) of 40 kgf/mm 2 or greater, an elongation (El) of 40 % or greater, and a truncated-cone height of 40 mm or greater in the conical cup test.
  • a method of producing a high-strength cold-rolled steel sheet suitable for working comprising the steps of:
  • Fig. 1 is a graph which shows the relationship between rolling reductions and various characteristics of the steel sheet.
  • a high-strength cold-rolled steel sheet having a superior workability specifically a Lankford value ( r ⁇ ) of 1.8 or greater, a tensile strength T.S.) of 40 kgf/mm 2 or greater, an elongation (El) of 40 % or greater and a truncated-cone height of 40 mm or greater, can be obtained by selecting the strain-imparting condition in the cold rolling of a very-low-carbon steel which is rich in P and small in oxygen content.
  • the present invention is based upon the above-described discovery. A description will be given first of the reason why the condition is posed that the sum of the rolling reductions of passes which meet the condition of T ⁇ ⁇ ⁇ 50,000°C S -1 between the sheet temperature (T °C) and the strain rate ⁇ (S -1 ) is 50 % or greater.
  • Three types of continuous-cast steel slabs A,B and C having the compositions shown in Table 1 were prepared by a converter.
  • Each slab was heated to 1250°C and rough-rolled at a rolling reduction of 88 %, followed by a hot finish-rolling at a rolling reduction of 88 % (hot-rolling finish temperature : 880°C, coiling temperature: 500°C) so as to be formed into a hot coil of 4.0 mm thick. Then, an ordinary cold rolling was effected at a rolling reduction of 82.5 % so that the steel was formed into a sheet 0.7 mm thick. Subsequently, a continuous annealing was conducted at 810°C followed by a temper rolling at a rolling reduction of 0.8 %, thereby producing a rolled steel sheet.
  • the cold rolling was conducted while varying the sheet temperature within the range of 30°C to 300°C, while varying the reduction rate, i.e,, the strain rate ⁇ within the range between 10 S -1 to 2,000 S -1 .
  • the sheet temperature was controlled by varying the initial sheet temperature for the cold rolling and the flow rate of the cooling water.
  • the Lankford value (r), elongation, tensile strength and truncated-cone height were measured for each of the sample steel sheets.
  • the truncated-cone height which is an index indicative of the workability approximating that in actual working was measured by a conical cup test conducted under the following conditions:
  • Fig. 1 shows the relationship between these measured values and the sum of the rolling reductions of the passes which meet the condition of the product of the cold rolling sheet temperature and the strain rate being not smaller than 50,000°C S -1 .
  • the low-oxygen steel material A rich in P exhibited a tensile strength (T.S.) which is smaller than that of the steel B which has a small P content.
  • T.S. tensile strength
  • the truncated-cone height indicative of the workability approximating that of actual working is remarkably improved to a value approximating that of the steel B which has a large tensile strength, while the elongation(El) and the Lankford value ( r ⁇ ) increase only slightly.
  • the steel C which is rich both in P and C does not show remarkable improvement in the properties indicative of the workability such as the Lankford value ( r ⁇ ), elongation (El) and the truncated-cone height.
  • the sum of the rolling reductions of passes which meet the condition of the product of the sheet temperature and the strain rate being 50,000 °C S -1 or greater is generally around 30 %.
  • suitable measures such as an increase in the rolling speed, control of flow rate of cooling water, or elevation of the initial cold rolling temperature through a continuous change from the preceding step, which is usually pickling.
  • the segregation zone does not produce any substantial unfavorable effect on the elongation Lankford value ( r ⁇ ) which is measured in tensile test. In the actual use of the material, however, the segregation zone reduces the uniformity of the steel sheet in the thicknesswise direction and, hence, is considered to cause a reduction in the workability.
  • the cold rolling conducted under the specified condition produces a working effect which serves to break the segregation zone, so that the uniformity of the structure in the thicknesswise direction of the steel sheet is improved so as to improve the workability as confirmed through the conical cup test which simulates the actual condition of use.
  • the oxygen content in the steel is large, however, the large quantity of the inclusions impedes the cold-rolling straining of P in the segregation zone so as to reduce the effect of improving the workability.
  • C serves, when added to the steel material together with Ti, to strengthens the steel without impairing workability.
  • the upper limit of C content,therefore is determined to be 0.02 wt%.
  • the C content is preferably below 0.006 wt%.
  • the steel making process and a subsequent hot rolling can be carried out in the same manner as the known process, except that the oxygen content is reduced by the method described above.
  • a material having satisfactory properties can be obtained when the coiling temperature of the steel after the hot rolling falls within the range of ordinary process, e.g., between 400°C and 700°C.
  • the coiling temperature is comparatively low, e.g., 550°C or less, in order to avoid any deterioration in pickling property caused by the thickening of scale and to prevent excessive softening of the product.
  • the cold rolling may be conducted by using an ordinary cold rolling mill, provided that the aforementioned cold rolling condition is met. Namely, it is necessary that the sum of the rolling reductions of passes which meets the condition of the product of the sheet temperature and the strain rate being not smaller than 50,000 °C S -1 is 50 % or greater. There is no restriction in the total rolling reduction, i.e.,the sum of the reductions of all passes employed, provided that the above-described condition is met.
  • the cold rolling sheet temperature has to be not higher than 300°C because a cold rolling at higher temperature causes concentration of shear deformation to the surface region of the steel sheet, making it difficult to work the central segregation zone.
  • the steel having the described composition When the steel having the described composition is annealed by batch-type box annealing method, the steel tends to become brittle due to grain boundary segregation of P due to high P content, particularly when the cooling rate is small.
  • a continuous annealing method which enables rapid heating and cooling.
  • the annealing temperature may be not lower than recrystallization temperature but not higher than A 3 transformation temperature, as in the case of ordinary steel annealing process.
  • the temper rolling subsequent to the annealing may be effected under ordinary steel tempering condition with a rolling reduction corresponding to the sheet thickness (mm), for the purpose of, for example, obtaining optimum shape of the sheet.
  • Ten types of steels including 7 types meeting the composition condition of the invention and 3 types as reference examples, were prepared in a converter and were continuously cast into slabs. Each slab was hot-rolled to form a hot coil of 3,0 mm thick and cold-rolled to a thickness of 0.72 mm. Subsequently, a continuous annealing was conducted under ordinary condition. Then, the steel sheets other than the type No. 3 were subjected to a temper rolling with a rolling reduction of 0.7 %, whereby 10 types of steel sheets including one which has not been subjected to temper rolling were prepared.
  • the roll used in the cold rolling had a diameter of 600 mm.
  • the cold rolling speed was 1500 to 2500 m/min at the outlet side of the cold rolling stand.
  • each of type Nos. 1 and 2 were subjected to three different production conditions with different cold-rolling and continuous annealing conditions,so that three samples were produced for each of the steel type Nos. 1 and 2. Similarly, two samples were prepared from the steel type No. 1 through different production conditions. Only one sample was prepared for each of the remainder steel types.
  • Table 3 shows the hot-rolling and continuous annealing conditions
  • Table 4 shows the cold rolling conditions
  • Table 5 shows the result of examination of the properties of the cold-rolled sample steel sheets.
  • Sample No. 3 was subjected to a galvannealing instead of the continuous annealing.
  • This galvannealed steel sheet also showed excellent workability as in the cases of other samples meeting the conditions of the invention.
  • Sample No. 6 was cold-rolled at a cold-rolling sheet temperature exceeding 300°C, although the sum of the rolling reductions of the passes having the product of the sheet temperature and the strain rate exceeding 50,000°C S -1 was greater than 50 %. Consequently, this sample showed a too small workability which was 20 mm in terms of truncated-cone height.
  • a method has been established by the present invention which enables production of a high-strength cold-rolled steel sheet having superior workability by processing a low-oxygen low-carbon steel rich in P under specific cold-rolling conditions.
  • the cold-rolled steel sheet produced by the method of the invention is suitable for use as a material of products which are produced through press-forming, bulging, deep-drawing and other plastic works.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)

Claims (4)

  1. Verfahren zum Herstellen eines hochfesten, kaltgewalzten, bearbeitbaren Stahlblechs mit den folgenden Schritten:
    Vorbereiten eines Stahls mit nicht mehr als 0,02 Gew.-% C, nicht mehr als 1,0 Gew.-% Si, nicht mehr als 2,0 Gew.-% Mn und nicht weniger als 0,01 Gew.-%, aber nicht mehr als 0,10 Gew.-% Ti, wobei der Gehalt an Ti, C und N derart bestimmt wird, daß die Bedingung Ti > (48/12) C Gew.-% + (48/14) N Gew.-% erfüllt ist, der Stahl außerdem nicht weniger als 0,0010 Gew.-%, aber nicht mehr als 0,0100 Gew.-% Nb, nicht weniger als 0,0002 Gew.-%, aber nicht mehr als 0,0020 Gew.-% B, nicht weniger als 0,03 Gew.-%, aber nicht mehr als 0,20 Gew.-% P, nicht mehr als 0,03 Gew.-% S, nicht weniger als 0,010 Gew.-%, aber nicht mehr als 0,100 Gew.-% Al, nicht mehr als 0,008 Gew.-% N, nicht mehr als 0,0045 Gew.-% O und als Rest Fe und die zugehörigen Verunreinigungen enthält;
    Gießen des Stahls in üblicher Weise mit nachfolgendem Warmwalzen;
    Kaltwalzen des warmgewalzten Stahls bei einer Blechtemperatur von nicht mehr als 300 °C unter der Bedingung, daß die Summe der Durchläufe der Höhenabnahme beim Walzen, die die folgende Bedingungen zwischen der Blechtemperatur (T °C) und der Umformgeschwindigung ε̇ (s-1): T x ε ̇ ≥ 50 000 °C s -1
    Figure imgb0017
     erfüllt, 50 % oder mehr ist und
    kontinuierliches Glühen des kaltgewalzten Stahls.
  2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß der Gehalt an P nicht weniger als 0,04 Gew.-% und nicht mehr als 0,15 Gew.-% und der Gehalt an O nicht mehr als 0,0040 Gew.-% beträgt.
  3. Verfahren nach Anspruch 1, gekennzeichnet durch ein hochfestes, kaltgewalztes Stahlblech mit einem Lankford-Wert ( r ¯
    Figure imgb0018
    ) von 1,8 und mehr, einer Zugefestigkeit (T.S.) von 40 kgf/mm2 oder mehr, einer Dehnung (Eℓ) von 40 % oder mehr und einer Kegelsenkhöhe im Kegelbechertest von 40 mm und mehr.
  4. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß anstelle des kontinuierlichen Glühens ein galvanisches Glühen durchgeführt wird.
EP91106841A 1990-06-20 1991-04-26 Verfahren zum Herstellen bearbeitbarer, hochfester, kaltgewalzter Stahlbleche Expired - Lifetime EP0462380B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP159856/90 1990-06-20
JP2159856A JPH0756051B2 (ja) 1990-06-20 1990-06-20 加工用高張力冷延鋼板の製造方法

Publications (3)

Publication Number Publication Date
EP0462380A2 EP0462380A2 (de) 1991-12-27
EP0462380A3 EP0462380A3 (en) 1993-10-06
EP0462380B1 true EP0462380B1 (de) 1996-11-13

Family

ID=15702727

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91106841A Expired - Lifetime EP0462380B1 (de) 1990-06-20 1991-04-26 Verfahren zum Herstellen bearbeitbarer, hochfester, kaltgewalzter Stahlbleche

Country Status (6)

Country Link
EP (1) EP0462380B1 (de)
JP (1) JPH0756051B2 (de)
KR (1) KR930004809B1 (de)
AU (1) AU632228B2 (de)
CA (1) CA2041403C (de)
DE (1) DE69123088T2 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2742769B1 (fr) * 1995-12-20 1998-01-16 Lorraine Laminage Acier lamine a froid presentant une bonne aptitude au soudage et au brasage
DE19915633A1 (de) * 1999-04-07 2000-10-12 Volkswagen Ag Schwenklager
KR100729125B1 (ko) * 2005-12-28 2007-06-14 현대하이스코 주식회사 소성 변형비가 우수한 고강도 냉연강판 및 그 제조 방법

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5819442A (ja) * 1981-07-27 1983-02-04 Nippon Kokan Kk <Nkk> 連続焼鈍による加工用高強度冷延鋼板の製造方法
JPS5884923A (ja) * 1981-11-16 1983-05-21 Nippon Steel Corp 高磁束密度低鉄損一方向性電磁鋼板の圧延方法
JPS6045689B2 (ja) * 1982-02-19 1985-10-11 川崎製鉄株式会社 プレス成形性にすぐれた冷延鋼板の製造方法
JPS59193221A (ja) * 1983-04-15 1984-11-01 Nippon Steel Corp 極めて優れた二次加工性を有する超深絞り用冷延鋼板の製造方法
DE3672853D1 (de) * 1985-03-06 1990-08-30 Kawasaki Steel Co Herstellung von verformbaren duennen stahlblechen mit ausgezeichneter widerstandsfaehigkeit gegen rillenbildung.
JPS61276927A (ja) * 1985-05-31 1986-12-06 Kawasaki Steel Corp 深絞り性の良好な冷延鋼板の製造方法
JPS6386819A (ja) * 1986-09-30 1988-04-18 Kawasaki Steel Corp 深絞り用冷延鋼板の製造方法
US4889566A (en) * 1987-06-18 1989-12-26 Kawasaki Steel Corporation Method for producing cold rolled steel sheets having improved spot weldability

Also Published As

Publication number Publication date
EP0462380A2 (de) 1991-12-27
DE69123088T2 (de) 1997-03-06
CA2041403C (en) 1997-04-22
EP0462380A3 (en) 1993-10-06
JPH0452230A (ja) 1992-02-20
JPH0756051B2 (ja) 1995-06-14
KR920000957A (ko) 1992-01-29
DE69123088D1 (de) 1996-12-19
KR930004809B1 (ko) 1993-06-08
AU7597191A (en) 1992-01-02
AU632228B2 (en) 1992-12-17
CA2041403A1 (en) 1991-12-21

Similar Documents

Publication Publication Date Title
EP0152665B1 (de) Kaltgewalzter Dual-Phasen-Stahl mit sehr guter Tiefziehfähigkeit und Herstellungsverfahren
EP0120976B1 (de) Herstellungsverfahren kaltgewalzten stahls zum tiefziehen
EP0048761B1 (de) Hochfestes, kaltgewalztes stahlblech sowie hochfestes, verzinktes stahlblech mit jeweils ausgezeichneter verformbarkeit und verfahren zur herstellung derselben
EP0731182B1 (de) Verfahren zum Herstellen von Stahlblechern geeignet zur Dosenherstellung
US4376661A (en) Method of producing dual phase structure cold rolled steel sheet
JP2001234282A (ja) 温間プレス成形性に優れた高張力熱延鋼板およびその製造方法
EP0064552B1 (de) Dünnes stahlblech zum tiefziehen mit vorzüglichen aushärtungseigenschaften nach dem lackieren und verfahren zu seiner herstellung
US4961793A (en) High-strength cold-rolled steel sheet having high r value and process for manufacturing the same
US5279683A (en) Method of producing high-strength cold-rolled steel sheet suitable for working
JP3864663B2 (ja) 高強度薄鋼板の製造方法
EP0462380B1 (de) Verfahren zum Herstellen bearbeitbarer, hochfester, kaltgewalzter Stahlbleche
EP0539962A1 (de) Verfahren zum Herstellen von kaltgewalzsten Stahlblechern mit hoher Beständigkeit gegen Versprödung durch Kaltbearbeitung und mit niedriger ebener Anisotropie
US5460665A (en) Method of manufacturing a low-alloy ultra-low-carbon cold anisotropy rolled steel sheet exhibiting an excellent resistance to fabrication embrittlement and small internal anisotropy
RU2815949C1 (ru) Способ получения горячекатаных листов из низколегированной стали
JP2001098327A (ja) 延性、加工性および耐リジング性に優れたフェライト系ステンレス鋼板の製造方法
JP3043901B2 (ja) 深絞り性に優れた高強度冷延鋼板及び亜鉛めっき鋼板の製造方法
KR940008064B1 (ko) 고가공용 열연강판의 제조방법
JPH03150316A (ja) 深絞り用冷延鋼板の製造方法
JPS6314817A (ja) 曲げ特性の優れた高強度薄鋼板の製造方法
JPH062069A (ja) 深絞り性に優れた高強度冷延鋼板及び溶融亜鉛めっき鋼板
CA1216499A (en) Method of producing cold rolled steel sheets for deep drawing
JPH05230541A (ja) 深絞り性に優れた高強度冷延鋼板及び亜鉛めっき鋼板の製造方法
JPH0784619B2 (ja) 深絞り性と耐２次加工脆性に優れた冷延鋼板の製造方法
JPS6352087B2 (de)
JPH05230539A (ja) 深絞り性に優れた高張力冷延鋼板の製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): BE DE ES FR GB IT NL

17P Request for examination filed

Effective date: 19920811

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): BE DE ES FR GB IT NL

17Q First examination report despatched

Effective date: 19950714

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE ES FR GB IT NL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRE;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.SCRIBED TIME-LIMIT

Effective date: 19961113

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19961113

REF Corresponds to:

Ref document number: 69123088

Country of ref document: DE

Date of ref document: 19961219

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20030429

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20030619

Year of fee payment: 13

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040430

BERE Be: lapsed

Owner name: *KAWASAKI STEEL CORP.

Effective date: 20040430

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20041101

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20041101

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20100325

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20100521

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20100430

Year of fee payment: 20

REG Reference to a national code

Ref country code: DE

Ref legal event code: R071

Ref document number: 69123088

Country of ref document: DE

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20110425

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20110425

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20110426