EP0613958A1 - Equipment for continuously annealing steel strips - Google Patents
Equipment for continuously annealing steel strips Download PDFInfo
- Publication number
- EP0613958A1 EP0613958A1 EP93910337A EP93910337A EP0613958A1 EP 0613958 A1 EP0613958 A1 EP 0613958A1 EP 93910337 A EP93910337 A EP 93910337A EP 93910337 A EP93910337 A EP 93910337A EP 0613958 A1 EP0613958 A1 EP 0613958A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- steel strip
- rolls
- roll
- bridle
- hearth
- 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.)
- Granted
Links
Images
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
- C21D9/54—Furnaces for treating strips or wire
- C21D9/56—Continuous furnaces for strip or wire
- C21D9/562—Details
- C21D9/563—Rolls; Drums; Roll arrangements
-
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
Definitions
- the higher the tension of a steel strip in the furnace in an apparatus for continuous annealing the better from the viewpoint of preventing walk or fluttering on one hand, and the lower the tension, the better from the viewpoint of preventing heat buckle.
- Fig. 2 is a diagram illustrating the general relation between the winding angles and tensions of a steel strip around bridle rolls.
- Fig. 3 is a diagram showing actual measurements of relations between the surface pressure and coefficient of friction of bridle rolls and hearth rolls as basic data for the present invention.
- roll diameters D will be 350 mm or less.
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)
Abstract
Description
- The present invention relates to an apparatus for continuously annealing a steel strip after cold rolling, wherein the term "steel strip" refers to steel products ultimately applicable to production of cans, steel furniture, automobiles, etc. after continuous annealing, and, if necessary, tin plating, zinc plating, etc.
- Generally, the higher the tension of a steel strip in the furnace in an apparatus for continuous annealing, the better from the viewpoint of preventing walk or fluttering on one hand, and the lower the tension, the better from the viewpoint of preventing heat buckle.
- To satisfy such contracting requirements, it is an ordinary operating practice to decrease the tension of steel strip in a heating furnace or a soaking furnace where the steel strip is at a high temperature and increase the tension in a cooling furnace or an overaging furnace where the steel strip is at a relative low temperature.
- Such tension distribution can be obtained by finely adjusting and controlling a hearth roll speed, and when it is desired to change the tension radically at a position in the furnace, it is an ordinary practice to provide a bridle roll in the furnace.
- Fig. 1 shows one example of that practice, where sets of
hearth rolls 3 are so arranged in the individual furnaces as to guide a steel strip 1 into the individual furnaces from the inlet side to the outlet side and a set ofbridle rolls 2 is arranged just before a rapid cooling furnace 6 in which the steel strip 1 that has passed through aheating furnace 4 and asoaking pit 5 is to be exposed to a gas jet stream of a high speed, and the tension of the steel strip 1 becomes largest after passing through the set ofbridle rolls 2. Then, the steel strip 1 passes through the successive quenching furnace 6, an overagingfurnace 7 and a final cooling furnace 8 under the largest tension. - A set of
bridle rolls 2 and sets ofhearth rolls 3 provided for these purposes must surely restrict the steel strip 1 so as to prevent any slip. Actually, the bridle rolls 2 andhearth rolls 3 have often slipped, particularly when the thickness of steel strip becomes smaller, and have failed to perform their proper functions. - An object of the present invention is to solve these problems and to provide an apparatus for continuously annealing a steel strip, capable of performing functions of bridle rolls and heath rolls so satisfactorily as to attain the stable operation of the apparatus for annealing.
- To solve the above-mentioned problems, the present invention provides apparatuses given in the following items (1) to (5):
- (1) An apparatus for continuously annealing a steel strip, which comprises furnaces and sets of rolls so arranged in the furnaces as to guide a steel strip fed into the furnaces from the inlet side to the outlet side, at least one roll of the sets of rolls having such a diameter D as to make a surface pressure p defined by the following equation (I) 10 kPa (kilopascal) or more:
wherein the unit tension of the steel strip at the inlet side to the roll is σ1, the unit tension at the outlet side to the roll is σ2, the thickness of the steel strip is h and the diameter of the roll is D. - (2) An apparatus as described in the above-mentioned item (1), wherein at least one roll of the sets of rolls is a bridle roll.
- (3) An apparatus as described in the above-mentioned item (1), wherein at least one roll of the sets of rolls is a hearth roll.
- (4) An apparatus for continuously annealing a steel strip, which comprises furnaces and sets of rolls so arranged in the furnaces as to guide a steel strip fed into the furnaces from the inlet side to the outlet side, at least one roll of the sets of rolls being a bridle roll having such a diameter D as to make a surface pressure p defined by the following equation (I) 10 kPa (kilopascal) or more:
wherein the unit tension of the steel strip at the inlet side to the each bridle roll is σ1, the unit tension at the outlet side to the each bridle roll is σ2, the thickness of the steel strip is h and the diameter of the bridle roll is D. - (5) An apparatus for continuously annealing a steel strip, which comprises furnaces and sets of rolls so arranged in the furnaces as to guide a steel strip fed into the furnaces from the inlet side to the outlet side, at least one roll of the sets of rolls being a hearth roll having such a diameter D as to make a surface pressure p defined by the following equation (I) 10 kPa (kilopascal) or more:
wherein the unit tension of the steel strip at the inlet side to the hearth roll is σ1, the unit tension at the outlet side to the hearth roll is σ2, the thickness of the steel strip is h and the diameter of the hearth roll is D. - A maximum tension T2 that cannot generate any slip technologically can be given by the following equation (II):
wherein the tension at the inlet side tobridle rolls 2 is T1, the tension at the outlet side is T2, winding angles of a steel strip 1 aroundbridle rolls - In other words, the tension ratio T2/T1 depends solely upon parameter µϑ and is independent on the absolute values of the tensions. However, the actual bridle rolls in the apparatus are liable to undergo slip when the absolute values of the tensions become smaller even in the same tension ratios. That is, it seems that the coefficient of friction µ is susceptible to tensions.
- Number of the bridle rolls is not limited, and only one bridle roll will do. Number of the bridle rolls can be determined from ϑ derived by inverse operation of the equation (II).
- As a result of measuring the coefficient of friction at slip generation limits of hearth rolls and bridle rolls having different diameters in an actual apparatus for continuous annealing, it has been found that the coefficient of friction is a function of surface pressure p given by the following equation (III).
wherein the diameter of a bridle roll is D and the width of a steel strip is W, as shown in Fig. 3. - An important fact is, as is apparent from Fig. 3, that the critical point of the coefficient of friction is at a surface pressure p of about 10 kPa (the surface pressure at this critical point will be hereinafter called a critical surface pressure pc).
- In a region whose surface pressure is at or above pc, the bridle rolls and the hearth rolls are in a state of normally restricting a steel strip, whereas in a region whose surface pressure is below pc they are in a slip state, that is, the friction is in a state of kinetic friction. In order to make the bridle rolls and hearth rolls normally function, their diameters must be so set that the surface pressure can be at or above pc.
- Generally, the object of hearth rolls is to convey a steel strip without changing tensions on the steel strip. The present inventor has found that the friction is in a state of kinetic friction below a surface pressure of 10 kPa, as is apparent from Fig. 3, and a slip occurs even due a slight difference in the tension between the inlet side and the outlet side to a hearth roll. The slip phenomenon, which appears even if there is no substantial difference in the tension, seems surprising, but since the control unit to motors driving the hearth rolls generally has no means for detecting a true travelling speed of steel strip, and the roll peripheral speed is thus controlled to an instructed value (same as the peripheral speed of a bridle roll), and thus such a phenomenon seems to appear. Furthermore, the roll peripheral speed is not controlled as instructed, because the hearth roll diameter thermally expanded in furnaces at an elevated temperature cannot be detected exactly, and thus this fact also promotes appearance of such a phenomenon. The slip presence leads to generation of defects on the steel strip, or buildups (fixation of iron component in the form of small spherical projections that also lead to defects of steel strip) on the surface of hearth roll due to continued slip. These problems can be solved by selecting appropriate roll diameters so as to give a critical surface pressure or more according to the present invention.
-
- Fig. 1 is a schematic side view showing an arrangement of bridle rolls and hearth rolls in the furnaces according to the present invention.
- Fig. 2 is a diagram illustrating the general relation between the winding angles and tensions of a steel strip around bridle rolls.
- Fig. 3 is a diagram showing actual measurements of relations between the surface pressure and coefficient of friction of bridle rolls and hearth rolls as basic data for the present invention.
- Examples are given below.
- One design example of bridle rolls based on the above-mentioned findings will be given below.
- Under the following conditions, i.e. unit tension of a steel strip at the inlet side to the bridle roll σ1 = 0.7 kg/mm², unit tension at the outlet side σ2 = 1.2 kg/mm², thickness of steel strip h = 0.25 mm, number of rolls = 3, winding angle of steel strip around the respective rolls = 180° and tension ratio at the respective rolls is constant (= σ2/σ1 = 1.2), a critical surface pressure pc = 10 kPa is inserted into the equation (IV) to obtain D1, D2 and D3. The results are D1 = 390 mm, D2 = 460 mm and D3 = 550 mm.
- Actual differences in the roll diameter give a complicatedness to their manufacturing and maintenance, and all roll diameters are set to constant 390 mm or less in view of safety.
- Data shown in Fig. 3 relate to smoothly finished bridle rolls and hearth rolls, each made of steel, and are those obtained at a line speed of 350 to 600 mpm.
- One design example of hearth rolls based on the above-mentioned findings will be given below.
- Tensions of a steel strip at the inlet side and the outlet side to the hearth rolls are generally constant (σ1 = σ2), and the equation (IV) can be applied to the hearth rolls as conditions for preventing slip occurrence in the same manner as in the case of bridle rolls.
- Under conditions of σ1 = σ2 = 0.7 kg/mm² and thickness of steel strip h = 0.25 mm, roll diameters D will be 350 mm or less.
- When the surface finishing roughness of bridle rolls or hearth rolls or the line speed considerably differs, there would be a possibility for a change in the critical surface pressure pc defined by Fig. 3, but there is no change in the basic concept of setting the bridle roll diameter or the hearth roll diameter to give the critical surface pressure or more.
- The concept of selecting roll diameters so that the surface pressure p can be at least such a critical value as not to cause any slip can be applied not only to the bridle rolls, but also to all the hearth rolls, as mentioned above.
- When the hearth roll diameter cannot be reduced due to the dimensional limit of the apparatus, as in a heating furnace provided with radiant tubes, care must be paid to the design and adjustment of the hearth roll control system so as not to give a driving force in excess of the necessary torque to the conveying of a steel strip by the hearth rolls. For example, speed instructions common to the furnaces must be limited so as not to cause an error in the speed over a predetermined value (a few mpm). It is also another technical knowledge suggested by the present invention to give an appropriate suspending characteristic, etc.
- As described above, bridle rolls and hearth rolls arranged in the apparatus for continuous annealing can give a sure tension-amplifying action to a steel strip as their proper function according to the present invention, thereby attaining a high level, stable operation in the apparatus for continuously annealing the steel strip, and also preventing serious defects such as occurrence of defects (flaws) due to a slip between the steel strip and the rolls.
Claims (5)
- An apparatus for continuously annealing steel strip, which comprises furnaces and sets of rolls so arranged in the furnaces as to guide a steel strip fed into the furnaces from the inlet side to the outlet side, at least one roll of the sets of rolls having such a diameter D as to make a surface pressure p defined by the following equation (I) 10 kPa (kilopascal) or more:
wherein the unit tension of the steel strip at the inlet side to the roll is σ1, the unit tension at the outlet side to the roll is σ2, the thickness of the steel strip is h and the diameter of the roll is D. - An apparatus according to Claim 1, wherein at least one roll of the sets of rolls is a bridle roll.
- An apparatus according to Claim 1, wherein at least one roll of the sets of rolls is a hearth roll.
- An apparatus for continuously annealing a steel strip, which comprises furnaces and sets of rolls so arranged in the furnaces as to guide a steel strip fed into the furnaces from the inlet side to the outlet side, at least one roll of the sets of rolls being a bridle roll having such a diameter D as to make a surface pressure p defined by the following equation (I) 10 kPa (kilopascal) or more:
wherein the unit tension of the steel strip at the inlet side to the bridle roll is σ1, the unit tension at the outlet side to the bridle roll is σ2, the thickness of the steel strip is h and the diameter of the bridle roll is D. - An apparatus for continuously annealing a steel strip, which comprises furnaces and sets of rolls so arranged in the furnaces as to guide a steel strip fed into the furnaces from the inlet side to the outlet side, at least one roll of the sets of rolls being a hearth roll having such a diameter D as to make a surface pressure p defined by the following equation (I) 10 kPa (kilopascal) or more:
wherein the unit tension of the steel strip at the inlet side to the hearth roll is σ1, the unit tension at the outlet side to the hearth roll is σ2, the thickness of the steel strip is h and the diameter of the hearth roll is D.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15624392 | 1992-05-25 | ||
JP15624392 | 1992-05-25 | ||
JP156243/92 | 1992-05-25 | ||
PCT/JP1993/000633 WO1993024664A1 (en) | 1992-05-25 | 1993-05-13 | Equipment for continuously annealing steel strips |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0613958A1 true EP0613958A1 (en) | 1994-09-07 |
EP0613958A4 EP0613958A4 (en) | 1996-10-23 |
EP0613958B1 EP0613958B1 (en) | 2000-08-23 |
Family
ID=15623509
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP93910337A Expired - Lifetime EP0613958B1 (en) | 1992-05-25 | 1993-05-13 | Process for continuously annealing steel strip |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0613958B1 (en) |
JP (1) | JP3203581B2 (en) |
KR (1) | KR960006583B1 (en) |
CN (1) | CN1028880C (en) |
DE (1) | DE69329272T2 (en) |
WO (1) | WO1993024664A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2762579B1 (en) | 2011-09-30 | 2017-08-16 | Nippon Steel & Sumitomo Metal Corporation | High-strength hot-dip galvanized steel sheet and process for producing same |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4495553B2 (en) * | 2004-09-10 | 2010-07-07 | 新日本製鐵株式会社 | Steel sheet fluttering suppression method |
KR101654158B1 (en) * | 2013-07-15 | 2016-09-09 | 주식회사 포스코 | Apparatus for heating slow cooling section in continuous annealing furnace |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4296919A (en) * | 1980-08-13 | 1981-10-27 | Nippon Steel Corporation | Apparatus for continuously producing a high strength dual-phase steel strip or sheet |
USRE30933E (en) * | 1969-12-30 | 1982-05-18 | Nippon Steel Corporation | Apparatus for continuous treatment of low-carbon cold-rolled steel sheet having excellent cold working properties |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5943979B2 (en) * | 1979-10-31 | 1984-10-25 | 川崎製鉄株式会社 | Furnace tension control method |
JPS607693B2 (en) * | 1979-10-31 | 1985-02-26 | 川崎製鉄株式会社 | Continuous annealing method for steel strip |
JPS56163224A (en) * | 1980-05-16 | 1981-12-15 | Nippon Steel Corp | Tension controller for metalllic strip |
JPH03173721A (en) * | 1989-11-30 | 1991-07-29 | Toshiba Corp | Device for controlling strip tension in continuous heat treatment furnace |
-
1993
- 1993-05-13 DE DE69329272T patent/DE69329272T2/en not_active Expired - Lifetime
- 1993-05-13 EP EP93910337A patent/EP0613958B1/en not_active Expired - Lifetime
- 1993-05-13 WO PCT/JP1993/000633 patent/WO1993024664A1/en active IP Right Grant
- 1993-05-13 JP JP50038594A patent/JP3203581B2/en not_active Expired - Lifetime
- 1993-05-13 KR KR1019930703730A patent/KR960006583B1/en not_active IP Right Cessation
- 1993-05-24 CN CN93106243A patent/CN1028880C/en not_active Expired - Lifetime
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USRE30933E (en) * | 1969-12-30 | 1982-05-18 | Nippon Steel Corporation | Apparatus for continuous treatment of low-carbon cold-rolled steel sheet having excellent cold working properties |
US4296919A (en) * | 1980-08-13 | 1981-10-27 | Nippon Steel Corporation | Apparatus for continuously producing a high strength dual-phase steel strip or sheet |
Non-Patent Citations (1)
Title |
---|
See also references of WO9324664A1 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2762579B1 (en) | 2011-09-30 | 2017-08-16 | Nippon Steel & Sumitomo Metal Corporation | High-strength hot-dip galvanized steel sheet and process for producing same |
US10351936B2 (en) | 2011-09-30 | 2019-07-16 | Nippon Steel & Sumitomo Metal Corporation | High-strength hot-dip galvanized steel sheet and process for producing the same |
Also Published As
Publication number | Publication date |
---|---|
KR960006583B1 (en) | 1996-05-20 |
DE69329272T2 (en) | 2001-02-08 |
DE69329272D1 (en) | 2000-09-28 |
CN1080661A (en) | 1994-01-12 |
EP0613958A4 (en) | 1996-10-23 |
JP3203581B2 (en) | 2001-08-27 |
KR940701456A (en) | 1994-05-28 |
CN1028880C (en) | 1995-06-14 |
EP0613958B1 (en) | 2000-08-23 |
WO1993024664A1 (en) | 1993-12-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4375283A (en) | Method of controlling tensions in continuous annealing furnace and system therefor | |
EP0155753B1 (en) | Cooling apparatus for strip metal | |
US5497817A (en) | Method for continuously annealing steel strip | |
EP0613958A1 (en) | Equipment for continuously annealing steel strips | |
US4145901A (en) | Rolling mill | |
EP0280259B1 (en) | Method and system for suppressing fluctuation of width in hot rolled strip or sheet metal | |
JP3927536B2 (en) | Transfer control method in continuous hot rolling line | |
JPH093553A (en) | Method for controlling tension in heat treatment furnace | |
JP3298465B2 (en) | Prevention method of sheet warpage in hot rolling | |
JPH0234496Y2 (en) | ||
EP0161861B1 (en) | Continuous annealing method and apparatus for cold rolled steel strips | |
JP3629127B2 (en) | Equipment for continuous annealing of strips | |
JP2003253343A (en) | Process for continuously heat treating metal strip | |
EP0108328A1 (en) | Continuous annealing apparatus | |
JP2004001031A (en) | Method for cold-rolling metal plate | |
JPH06228660A (en) | Method for controlling crown of hearth roll | |
JPS6386820A (en) | Tension control method for metallic strip in continuous annealing furnace | |
JP2022049156A (en) | Tempering rolling facility, and manufacturing method of metal plate | |
JPH06108161A (en) | Method for continuously annealing metal strip | |
JP2789819B2 (en) | Method of preventing drawing of steel strip in continuous annealing furnace | |
JPS61179819A (en) | Cooling method of metallic strip | |
JP2005271025A (en) | Cold-rolling method | |
JP2921420B2 (en) | Combustion control method in continuous annealing furnace | |
JPH0559178B2 (en) | ||
JPH04285129A (en) | Method for preventing heat buckle |
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: 19940224 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB IT |
|
A4 | Supplementary search report drawn up and despatched |
Effective date: 19960902 |
|
AK | Designated contracting states |
Kind code of ref document: A4 Designated state(s): DE FR GB IT |
|
17Q | First examination report despatched |
Effective date: 19981124 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
RTI1 | Title (correction) |
Free format text: PROCESS FOE CONTINUOUSLY ANNEALING STEEL STRIP |
|
RTI1 | Title (correction) |
Free format text: PROCESS FOR CONTINUOUSLY ANNEALING STEEL STRIP |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
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): DE FR GB IT |
|
ITF | It: translation for a ep patent filed |
Owner name: SOCIETA' ITALIANA BREVETTI S.P.A. |
|
REF | Corresponds to: |
Ref document number: 69329272 Country of ref document: DE Date of ref document: 20000928 |
|
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: DE Payment date: 20120510 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: 20120608 Year of fee payment: 20 Ref country code: GB Payment date: 20120509 Year of fee payment: 20 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20120516 Year of fee payment: 20 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 69329272 Country of ref document: DE Representative=s name: VOSSIUS & PARTNER, DE Effective date: 20130227 Ref country code: DE Ref legal event code: R081 Ref document number: 69329272 Country of ref document: DE Owner name: NIPPON STEEL & SUMITOMO METAL CORPORATION, JP Free format text: FORMER OWNER: NIPPON STEEL CORP., TOKIO/TOKYO, JP Effective date: 20130227 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R071 Ref document number: 69329272 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: PE20 Expiry date: 20130512 |
|
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: 20130512 Ref country code: DE Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20130514 |