EP0032583B1 - Verfahren zur kontinuierlichen Wärmebehandlung eines kaltgewalzten Stahlbandes - Google Patents

Verfahren zur kontinuierlichen Wärmebehandlung eines kaltgewalzten Stahlbandes Download PDF

Info

Publication number
EP0032583B1
EP0032583B1 EP80108148A EP80108148A EP0032583B1 EP 0032583 B1 EP0032583 B1 EP 0032583B1 EP 80108148 A EP80108148 A EP 80108148A EP 80108148 A EP80108148 A EP 80108148A EP 0032583 B1 EP0032583 B1 EP 0032583B1
Authority
EP
European Patent Office
Prior art keywords
steel strip
temperature
cooling
overaging
process according
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
Application number
EP80108148A
Other languages
English (en)
French (fr)
Other versions
EP0032583A1 (de
Inventor
Hajime Nitto
Hiromitsu Naito
Takao Saito
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.)
Nippon Steel Corp
Original Assignee
Nippon 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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=26491070&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0032583(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from JP16682679A external-priority patent/JPS5933171B2/ja
Priority claimed from JP16682779A external-priority patent/JPS5933172B2/ja
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Publication of EP0032583A1 publication Critical patent/EP0032583A1/de
Application granted granted Critical
Publication of EP0032583B1 publication Critical patent/EP0032583B1/de
Expired legal-status Critical Current

Links

Classifications

    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length

Definitions

  • the present invention relates to a process for continuously annealing a cold rolled steel strip. More particularly, the present invention relates to a process for continuously annealing a cold rolled steel strip, which process is capable of completing the annealing operation within a short time and; also, capable of obtaining a cold rolled steel strip having an excellent workability, especially formability, and an excellent surface quality, at a low cost.
  • the continuous annealing method can exhibit an extremely high efficiency in comparison with the conventional batch type annealing method. However, it is strongly desired to increase the efficiency of the continuous annealing method to such an extent that the continuous annealing operation is completed within a few minutes.
  • the heating and cooling operations result in the formation of a considerably large thickness of the oxide layer, and this large thickness causes the time necessary for completing the elimination of the oxide layer to be undesirably long.
  • the sheet surface is coarsened due to the pickling for removing the oxide layer.
  • the elimination of the oxide layer from the steel strip is carried out during the reheating overaging operation at a relatively low temperature. Therefore, in order to effectively attain the elimination of the oxide layer, the reducing operation should be carried out by using a strictly controlled reducing atmosphere having a special concentration of hydrogen and dew point. Also, in the processes (1) and (2), in order to overage the steel strip after the rapid cooling, it is necessary to reheat the steel strip to an overaging temperature thereof.
  • the combustion air ratio is adopted as a parameter of the combustion condition in the direct fired furnace.
  • the oxidation tendency of the sheet surface is dependent upon the combustion air ratio.
  • DE-B 2 133 411 discloses a continuous cooling treatment for an annealed steel strip by application of quenching water which is jetted with high pressure in sheet form onto the strip, the cooling rate of latter being in the range of from 500°C/s to 2000°C/s. This quenching with water is very rapid, and it is difficult to obtain controlled moderate cooling rates. According to DE-B 2 133 411 1 the quenching is carried out until a temperature of about 100°C is reached. For the following shelfing treatment the strip has to be reheated until the desired temperature in the range of from 400°C to 500°C is reached.
  • DE-B 2 165 049 discloses a method of quench hardening a metal plate, comprising spraying a water fog onto a hot metal plate, said fog being generated by means of special fog nozzles in which water and pressurized air are mixed. Separate jet nozzles for gas and liquid respectively are used.
  • the present invention involves a concept of combining the following:
  • the process without the overaging step of the present invention can be applied to cold-rolled non- aging low carbon steel strips, for example, cold-rolled, extremely low carbon aluminium killed steel strips, and cold-rolled non- or retarded-aging extremely low carbon steel strips containing a small amount of Ti, Nb, V or B, which are capable of forming carbonitrides.
  • the process of the present invention can be applied to various cold-rolled low carbon steel strips which include the usual type of cold-rolled low carbon steel strips having a drawing quality and a deep drawing quality, for example, bodies of automobiles, high tensile strength cold-rolled low carbon steel strips and other types of cold-rolled low carbon steel strips suitable for various surface-treating processes, for example, metal plating and coating processes. Since, there is no necessity of overaging in the non- or retarded-aging steels, the steel strips are directly pickled after cooling, so as to remove the oxide layer.
  • the primary cooling operation is followed by an overaging operation.
  • the overaging operation is usually applied to them.
  • the cooling operation must be terminated when the temperature of the steel strip reaches a level near an overaging temperature of the steel strip, the cooled steel strip may be overaged and, then, the overaged steel strip may be additionally cooled to a desired temperature.
  • the peripheral surface of the cold-rolled steel strip may be cleaned to remove grease or rolling oil therefrom by a conventional surface-cleaning method. Otherwise, the process of the present invention may be applied to the cold rolled steel strip without surface-cleaning- it.
  • radiation heating means such as a radiant-tube heating and other appropriate heating means, are employed for heating the steel strip to a temperature within the range of from the recrystallization temperature to the Ac 3 point of the steel strip and also for holding the steel strip within the temperature range of from the recyrstallization temperature to the A C3 point over a period of at least 10 seconds, preferably from 10 to 60 seconds in a non-oxidizing or reducing atmosphere.
  • the present invention is characterized as compared with the prior arts in the combination use of the radiation heating furnace for heating steel strip to and holding it within the requisite annealing temperature range, cooling the steel strip by spraying a specifically generated cooling medium consisting of a mixture of an inert gas and a liquid, a pickling removal of the oxide layer formed by the cooling and overaging without reheating, if overaging is necessary.
  • the holding temperature depends on the composition and the other properties of the steel strip, as well as the objective properties of the final product.
  • the holding temperature is not always constant but may be varied in the direction of the holding zone so as to adapt the heat cycle for recrystallization and growth of crystal grains.
  • the heating rate is lower than that of the direct fired heating, but the surface deterioration due to the direct contact of flame with the sheet surface is prevented.
  • the pickling time in the final step is shortened as compared with that of steel strips heated in the direct fired furnace, and also a surface quality problem involved in the pickling is mitigated.
  • the non-oxidizing or reducing atmosphere inert to the steel is employed for the furnace atmosphere and is maintained during the heating and holding zones, the oxidation of the sheet surface in these zones is prevented.
  • the pickling at the final step is carried out at an extent sufficient to remove only a thin oxide layer formed at this cooling step or the primary cooling step.
  • the fact that no oxide layer is formed during the heating step advantageously leads to the prevention of the oxide pick up on the hearth rollers.
  • the reducing atmosphere preferably comprises a mixture of 4% by volume or more of hydrogen gas, with the balance consisting of nitrogen gas, and preferably exhibits a dew point of 10°C or less.
  • the steel strip which is subjected to the holding in a radiation heating furnace, is then rapidly cooled at a cooling rate from 10 to 300°C/second which is preferable from the view points of the metallurgical properties of the annealed steel strip.
  • the steel strip may be directly rapid-cooled from the holding temperature, or may be slow-cooled from the holding temperature to a temperature of preferably 600°C at the lowest and then rapid-cooled, if necessary.
  • the rapid cooling must start at a temperature between the above holding temperature and 600°C from the view points of shortening the overaging time period.
  • gas-liquid cooling medium means a fluid which is produced through such a process that a high speed inert gas stream and a liquid stream of a predetermined pressure are injected from their respective nozzles as jet streams and these streams are then mixed with each other by intersecting with each other so that the liquid (e.g., water) reduces itself to fine particles mixed in the gas in the form of a mist, or in a form almost equivalent to spray.
  • the liquid is preferably water and the gas is selected from inert gases, such as nitrogen gas, and mixtures of nitrogen and hydrogen.
  • the gas-liquid cooled medium consists of a mixture of nitrogen gas with water.
  • the overaging operation is carried out for the purpose of precipitating carbon in the steel matrix which has been super-saturated with a solid solution carbon.
  • the overaging operation is preferably carried out in a temperature range of from 300 to 550°C, more preferably, from 350 to 450°C, for 3 minutes or less, more preferably 2 minutes or less. It is not always necessary that the steel strip be maintained at a constant temperature throughout the overaging operation. That is, the overaging temperature in an initial stage of the overaging operation may be higher than that in a final stage of the overaging operation.
  • the temperature profile from the entry to withdrawal ends of the overaging equipment may be gradual or may decrease stepwise,
  • the peripheral surface portion of the steel strip cannot be prevented from oxidation. That is, the resultant layer of oxides causes the appearance of the steel strip surface to be unsatisfactory, and the surface property of the steel strip to be unsuitable to the surface treatments. Therefore, it is necessary to eliminate the layer of oxides from the peripheral surface of the steel strip.
  • the elimination of the oxide layer is effected by any conventional pickling methods effective for eliminating various oxides.
  • the oxide layer can be removed by treating the peripheral surface of the steel strip with, for example, an acid aqueous solution of an inorganic acid, such as hydrochloric acid, sulfuric acid or phosphoric acid, or an organic acid, such as formic acid or oxalic acid.
  • the treatment may be effected by immersing the steel strip in an acid aqueous solution, by spraying the acid aqueous solution onto a peripheral surface of the steel strip, or by subjecting the steel strip to an electrolytic pickling with an acid aqueous solution.
  • the oxide layer formed in the cooling and , optionally, overaging operations is very thin. Therefore, the oxide layer can be readily eliminated by the above-mentioned methods.
  • the pickled steel strip is rinsed with water.
  • the rinsed steel strip be neutralized with a diluted alkali aqueous solution. This neutralization is effective for preventing rust and discoloration of the peripheral surface of the steel strip.
  • the cold rolled steel strip for example, to be used for producing an automobile body, is coated before the working process.
  • the surface of steel strip is treated with zinc phosphate.
  • the quality of the zinc phosphate film formed on the surface of the steel strip can be improved by applying the following treatment to the steel strip after the pickling operation.
  • an aqueous suspension containing water-insoluble phosphate for example, Zn,(P0 4 ) 21 is sprayed onto the surface of the pickled steel strip, or a thin film of Ni, Zn or Mn is flash-coated on the pickled steel strip surface by means of electroplating. Thereafter, as a precoating operation the surface of steel strip is treated with the zinc phosphate.
  • the above-mentioned surface pre-treatment is effective for promoting the formation of crystal nuclei of the zinc phosphate and for providing a dense film of the zinc phosphate. Therefore, the above-mentioned surface pre-treatment is very effective for enhancing the bonding strength of the zinc phosphate layer to the coating layer and for increasing the resistance of the coating layer to corrosion.
  • the process of the present invention can exhibit the following advantages.
  • 0.8 mm thick cold rolled steel strips were processed under the conditions given in Table 1.
  • the oxide film thickness in the comparative examples 1 and 2 was determined by preliminary experiments, in which the steel strips were heated under the same condition as in these examples by a direct fired furnace followed by a rapid cooling means of blowing nitrogen gas on the strips in the next zone. Samples were cut from the strips and pickled in a 5% hydrochloric acid aqueous solution. The weight decrease of samples due to pickling was reduced to the thickness of the oxide layer of FeO.
  • the 0.8 mm thick cold rolled steel strips were processed under the conditions given in Table 2.
  • the oxide layer thickness was determined by the same procedure as described above.

Landscapes

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

Claims (11)

1. Verfahren zum kontinuierlichen Glühen eines kaltgewalzten Stahlbandes, das die Schritte umfaßt:
Einführen eines kaltgewalzten Stahlbandes in wenigstens einen Strahlungswärme -Ofen, in dem das genannte Stahlband auf eine Temperatur im Bereich von der Rekristallisationstemperatur bis zu dem AC3-Punkt des genannten Stahlbandes aufgeheizt und innerhalb des genannten Temperaturbereichs für einen Zeitraum von wenigstens 10 Sek. gehalten wird, wobei eine nicht-oxidierende oder reduzierende Atmosphäre in den Erhitzungs- und Halte-Zonen des genannten wenigstens einen Strahlungswärme-Ofens aufrechterhalten wird,
Abkühlen des genannten Stahlbandes durch Aufsprühen eines Kühlmediums, das aus einer Mischung eines Inertgases mit einer Flüssigkeit besteht, wobei dieses Kühlmedium durch Ausblasen eines Hochgeschwindigkeitsgasstroms und eines Flüssigkeitsstroms eines vorgegebenen Drucks aus ihren entsprechenden Düsen in Form von Düsenstrahlen sowie Vermischen dieser Strahlen miteinander durch deren Überkreuzung erzeugt wird und
Beizen des genannten Stahlbandes.
2. Verfahren zum kontinuierlichen Glühen eines kaltgewalzten Stahlbandes, das die Schritte umfaßt:
Einführen eines kaltgewalzten Stahlbandes in wenigstens einen Strahlungswärme-Ofen, in dem das genannte Stahlband auf eine Temperatur im Bereich von der Rekristallisations-Temperatur bis zum AC3-Punkt des genannten Stahlbandes aufgeheizt und innerhalb dieses Temperaturbereichs über einen Zeitraum von wenigstens 10 Sek. gehalten wird, wobei eine nicht-oxidierende oder reduzierende Atmosphäre in den Erhitzungs- und Halte-Zonen des genannten wenigstens einen Strahlungswärme-Ofens aufrechferhalten wird,
Abkühlen des genannten Stahlbandes durch Aufsprühen eines Kühlmediums, das aus einer Mischung eines Inertgases mit einer Flüssigkeit besteht, wobei dieses Kühlmedium durch Ausblasen eines Hochgeschwindigkeits-Gasstroms und eines Flüssigkeitsstroms eines vorgegebenen Drucks aus ihren entsprechenden Düsen in Form von Düsenstrahlen sowie das Vermischen dieser Strahlen durch deren Überkreuzen erzeugt wird,
wobei das genannte Kühlen innerhalb eines Primärkühlungs-Temperaturbereichs von mindestens 600°C bis zu einer Temperatur in der Nähe einer (Jbervergütungs-Behandlungstemperatur durchgeführt wird,
Übervergüten des genannten primärgekühlten Stahlbandes,
Sekundärkühlen des genannten übervergüteten Stahlbandes und
Beizen des genannten seKundärgeKühlten Stahlbandes,
3. Verfahren nach Anspruch 1 oder 2, bei dem die Kühlgeschwindigkeit unter Verwendung des genannten Kühlmediums im Bereich von 10 bis 300°C/s liegt.
4. Verfahren nach Anspruch 1 oder 2, bei dem die genannte Flüssigkeit Wasser ist.
5. Verfahren nach Anspruch 1 oder 2, bei dem das genannte Inertgas Stickstoff ist.
6. Verfahren nach Anspruch 1 oder 2, bei dem die Haltezeit im Bereich von 10 bis 60 Sek. liegt und eine nicht-oxidierende oder reduzierende Atmosphäre in den Erhitzungs- und Halte-Zonen des genannten wenigstens einen Strahlungswärme-Ofens aufrechterhalten wird.
7. Verfahren nach Anspruch 2, bei dem die genannte Übervergütungs-Behandlung innerhalb eines Temperaturbereichs von 300 bis 550°C für 3 Min. oder weniger durchgeführt wird.
8. Verfahren nach Anspruch 2, bei dem die genannte Übervergütungs-Behandlung innerhalb eines Temperaturbereichs von 350°C bis 450°C durchgeführt wird.
9. Verfahren nach Anspruch 1 oder 2, bei dem das genannte Beizen mit einer wäßrigen Lösung durchgeführt wird, die wenigstens eine Säure enthält, die aus der Gruppe ausgewählt ist, die aus Salzsäure, Schwefelsäure, Phosphorsäure, Ameisensäure und Oxalsäure besteht.
10. Verfahren nach Anspruch 1 oder 2, bei dem der genannte Beizschritt das Neutralisieren des säuregereinigten Stahlbandes umfaßt.
11. Verfahren nach Anspruch 2, bei dem eine Übervergütungs-Temperatur in einer Anfangsstufe der Übervergütungs-Behandlung höher ist als die in einer Endstufe der Übervergütungs-Behandlung.
EP80108148A 1979-12-24 1980-12-22 Verfahren zur kontinuierlichen Wärmebehandlung eines kaltgewalzten Stahlbandes Expired EP0032583B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP166827/79 1979-12-24
JP16682679A JPS5933171B2 (ja) 1979-12-24 1979-12-24 冷延鋼板の連続焼鈍方法
JP166826/79 1979-12-24
JP16682779A JPS5933172B2 (ja) 1979-12-24 1979-12-24 冷延鋼板の連続焼鈍処理方法

Publications (2)

Publication Number Publication Date
EP0032583A1 EP0032583A1 (de) 1981-07-29
EP0032583B1 true EP0032583B1 (de) 1984-08-01

Family

ID=26491070

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80108148A Expired EP0032583B1 (de) 1979-12-24 1980-12-22 Verfahren zur kontinuierlichen Wärmebehandlung eines kaltgewalzten Stahlbandes

Country Status (4)

Country Link
EP (1) EP0032583B1 (de)
BR (1) BR8008511A (de)
CA (1) CA1152870A (de)
DE (1) DE3068827D1 (de)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5767134A (en) * 1980-10-09 1982-04-23 Nippon Steel Corp Method and installation for continuous annealing method of cold-rolled steel strip
DE3580055D1 (de) * 1984-04-05 1990-11-15 Stein Heurtey Entfettungsverfahren fuer kaltgewalztes stahlband.
FR2562563B1 (fr) * 1984-04-05 1988-09-23 Stein Heurtey Procede de degraissage d'une bande metallique laminee a froid
CN112111638B (zh) * 2020-09-27 2022-05-24 攀钢集团研究院有限公司 低碳冷轧钢板的分级生产方法
CN112593051B (zh) * 2020-12-07 2022-01-25 山东钢铁集团日照有限公司 一种预防氧化铁皮生成的退火炉快速点炉升温的方法
CN115058582A (zh) * 2022-07-14 2022-09-16 上海曙佳科技发展有限公司 一种连退炉炉内可视化及工件温度管理方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2165049B2 (de) * 1970-12-28 1973-11-15 Nippon Kokan K.K., Tokio Verfahren und Vorrichtung zum Abschrecken

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4923727B1 (de) * 1969-12-16 1974-06-18
JPS535607B2 (de) * 1973-01-11 1978-03-01

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2165049B2 (de) * 1970-12-28 1973-11-15 Nippon Kokan K.K., Tokio Verfahren und Vorrichtung zum Abschrecken

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Patents Abstracts of Japan Vol. 4, No. 22, 23 February 1980, page 128C74 *
Patents Abstracts of Japan, Vol. 1, No. 64, 22 June 1977, page 995C77 *

Also Published As

Publication number Publication date
CA1152870A (en) 1983-08-30
EP0032583A1 (de) 1981-07-29
BR8008511A (pt) 1981-07-21
DE3068827D1 (en) 1984-09-06

Similar Documents

Publication Publication Date Title
CA1137394A (en) Process for continuously annealing a cold-rolled low carbon steel strip
EP0032583B1 (de) Verfahren zur kontinuierlichen Wärmebehandlung eines kaltgewalzten Stahlbandes
KR101543876B1 (ko) 도금 밀착성이 우수한 고강도 Zn-Al-Mg 합금용융아연도금강판 제조방법
US4981531A (en) Process for producing cold rolled steel sheets having excellent press formability and ageing property
JPS5884929A (ja) 非時効性で塗装焼付硬化性の優れた深絞り用冷延鋼板の製造法
JPH02285057A (ja) 溶融亜鉛めっき用鋼板の連続焼鈍方法
JPS6345322A (ja) ホ−ロ−用鋼板の製造方法
JPS6356291B2 (de)
JPS5818973B2 (ja) プレス成形性の優れた高張力冷延鋼板の製造方法
KR850000579B1 (ko) 냉간 압연강 스트립(strip)의 연속 어니일링 방법
JP3020846B2 (ja) 高張力溶融亜鉛めっき鋼板の製造方法
EP0434849B1 (de) Verfahren zur herstellung von stahlblechen zur emaillierung mit verbesserter emailhaftung
GB2066290A (en) Processes for producing high strength cold rolled steel sheets
US3420718A (en) Process for the production of very low carbon-containing cold-rolled steel strips
RU2040556C1 (ru) Способ производства полос из малоуглеродистой горячекатаной стали
CN115612816B (zh) 含硼钢制备复相钢、热成形用钢镀层板的方法
US4294632A (en) Method for overaging of hot dip metal coated steel material
JPS5933172B2 (ja) 冷延鋼板の連続焼鈍処理方法
JPH10317121A (ja) 塗装下地用溶融亜鉛めっき鋼板の製造方法
KR850000348B1 (ko) 냉간 압연된 저탄소 강스트립을 연속적으로 아닐링하는 공정
JPS5933171B2 (ja) 冷延鋼板の連続焼鈍方法
SU1303623A1 (ru) Способ производства тонкой высокопрочной стальной полосы,с покрытием из железоцинкового сплава
JPS5842250B2 (ja) 冷延鋼板の連続焼鈍処理法
JPH0459984B2 (de)
JPH01180916A (ja) 密着性および耐泡性の優れたほうろう用鋼板の製造方法

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

17P Request for examination filed

Effective date: 19801222

AK Designated contracting states

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

ITF It: translation for a ep patent filed

Owner name: STUDIO TORTA SOCIETA' SEMPLICE

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

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

REF Corresponds to:

Ref document number: 3068827

Country of ref document: DE

Date of ref document: 19840906

ET Fr: translation filed
PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: THYSSEN STAHL AG

Effective date: 19850502

NLR1 Nl: opposition has been filed with the epo

Opponent name: THYSSEN STAHL AG

PLBN Opposition rejected

Free format text: ORIGINAL CODE: 0009273

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

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 19871004

NLR2 Nl: decision of opposition
ITTA It: last paid annual fee
EAL Se: european patent in force in sweden

Ref document number: 80108148.0

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

Ref country code: GB

Payment date: 19951213

Year of fee payment: 16

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

Ref country code: SE

Payment date: 19951215

Year of fee payment: 16

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

Ref country code: NL

Payment date: 19951230

Year of fee payment: 16

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

Ref country code: BE

Payment date: 19960130

Year of fee payment: 16

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

Ref country code: GB

Effective date: 19961222

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

Ref country code: SE

Effective date: 19961223

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

Ref country code: BE

Effective date: 19961231

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

Ref country code: DE

Payment date: 19961231

Year of fee payment: 17

BERE Be: lapsed

Owner name: NIPPON STEEL CORP.

Effective date: 19961231

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

Ref country code: NL

Effective date: 19970701

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19961222

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

Effective date: 19970701

EUG Se: european patent has lapsed

Ref document number: 80108148.0

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 NON-PAYMENT OF DUE FEES

Effective date: 19980901

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

Ref country code: FR

Payment date: 19991208

Year of fee payment: 20