EP1999287A1 - Method for continuously annealing and preparing strip of high-strength steel for the purpose of hot-dip galvanizing it - Google Patents
Method for continuously annealing and preparing strip of high-strength steel for the purpose of hot-dip galvanizing itInfo
- Publication number
- EP1999287A1 EP1999287A1 EP07719191A EP07719191A EP1999287A1 EP 1999287 A1 EP1999287 A1 EP 1999287A1 EP 07719191 A EP07719191 A EP 07719191A EP 07719191 A EP07719191 A EP 07719191A EP 1999287 A1 EP1999287 A1 EP 1999287A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- heating
- strip
- section
- atmosphere
- cooling
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000010959 steel Substances 0.000 title claims abstract description 32
- 238000000137 annealing Methods 0.000 title claims abstract description 21
- 238000005246 galvanizing Methods 0.000 title description 9
- 238000010438 heat treatment Methods 0.000 claims abstract description 45
- 239000012298 atmosphere Substances 0.000 claims abstract description 40
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000001301 oxygen Substances 0.000 claims abstract description 28
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 28
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 27
- 238000001816 cooling Methods 0.000 claims abstract description 23
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 23
- 239000001257 hydrogen Substances 0.000 claims abstract description 22
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 20
- 230000001590 oxidative effect Effects 0.000 claims abstract description 19
- 230000009467 reduction Effects 0.000 claims abstract description 13
- 229910001338 liquidmetal Inorganic materials 0.000 claims abstract description 7
- 238000003618 dip coating Methods 0.000 claims abstract description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 19
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 16
- 239000011701 zinc Substances 0.000 claims description 16
- 229910052725 zinc Inorganic materials 0.000 claims description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- 230000008569 process Effects 0.000 claims description 11
- 238000012423 maintenance Methods 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 10
- 239000007789 gas Substances 0.000 claims description 9
- 239000011261 inert gas Substances 0.000 claims description 9
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 239000011248 coating agent Substances 0.000 claims description 7
- 238000000576 coating method Methods 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 5
- 238000005244 galvannealing Methods 0.000 claims description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 230000005855 radiation Effects 0.000 claims description 4
- 238000000926 separation method Methods 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 239000008246 gaseous mixture Substances 0.000 claims description 2
- 230000006698 induction Effects 0.000 claims description 2
- 238000002347 injection Methods 0.000 claims description 2
- 239000007924 injection Substances 0.000 claims description 2
- 238000011144 upstream manufacturing Methods 0.000 claims description 2
- 239000007800 oxidant agent Substances 0.000 claims 1
- 238000005275 alloying Methods 0.000 description 8
- 230000003647 oxidation Effects 0.000 description 8
- 238000007254 oxidation reaction Methods 0.000 description 8
- 238000007654 immersion Methods 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 229910052782 aluminium Inorganic materials 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 4
- 229910052710 silicon Inorganic materials 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910001297 Zn alloy Inorganic materials 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 235000014066 European mistletoe Nutrition 0.000 description 1
- 208000036119 Frailty Diseases 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 235000012300 Rhipsalis cassutha Nutrition 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 241000221012 Viscum Species 0.000 description 1
- 206010003549 asthenia Diseases 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 239000010731 rolling oil Substances 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
- C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
- C23C2/0222—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating in a reactive atmosphere, e.g. oxidising or reducing atmosphere
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
- C23C2/022—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by heating
- C23C2/0224—Two or more thermal pretreatments
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
- C23C2/36—Elongated material
- C23C2/40—Plates; Strips
Definitions
- the present invention relates to a new annealing process and continuous preparation of a high-strength steel strip for its coating by hot quenching in a bath of liquid metal, preferably a galvanization or a. so-called "galvannealing" treatment.
- the technical field considered here is that of galvanization by continuous scrolling in a coating bath composed of zinc or zinc alloy strips of steel. heavily loaded with alloying elements, especially HSS steels (high strength steels).
- HSS steels high strength steels.
- These special steels known to be difficult to galvanize are, for example, steels which may contain levels of alloying elements (aluminum, manganese, silicon, chromium, etc.) up to .
- the water vapor is generated here by the reduction of the iron oxide, always present on the cold-rolled sheet, by the hydrogen contained in the atmosphere of the annealing furnaces. [0004] Therefore, it has been sought to eliminate the selective oxidation in external mode or to make it migrate inside the steel, at 1 or 2 ⁇ m under the outer layer of the surface, to make it possible to present the zinc liquid a layer of substantially pure metal iron, regardless of the alloy composition and promoting the attachment of zinc coating or zinc alloy.
- pre-deposition of iron or nickel for example JP-A-04 280925, JP-A-2005/105399.
- an annealing installation and preparation of a steel strip for galvanizing typically comprises, in the direction of progression of the strip:
- a first (pre) heating section heating the strip to a temperature allowing the formation of an oxide film of adequate thickness (about 50 nanometers) for its subsequent reduction;
- this section is under an oxidizing atmosphere by adding air or oxygen, for example in the form of an air / fuel mixture gas in the case of a direct flame furnace or air alone in le case of a radiant furnace;
- a second annealing section separated from the heating section by a conventional airlock, where the strip is kept at the high annealing temperature and which is under an inert atmosphere at overpressure, to prevent the entry of gases from the heating section;
- a third reduction section also separated from the second section by a conventional airlock, under an atmosphere slightly depressed with respect thereto but at a slight overpressure with respect to the ambient; this section is intended to finish the annealing cycle
- the oxide layer created in the first section is ideally reduced completely by a hydrogen / inert gas atmosphere with a very low dew point.
- the present invention aims to provide a solution that makes it possible to overcome the disadvantages of the state of the art.
- the invention aims to provide a method of annealing and preparation for galvanizing high strength steels which is more economical, the latter being carried out with or without accompanying heat treatment galvannealing type.
- the invention also aims to allow a preparation of high strength steels for galvanizing, which are free of brittleness defects.
- the invention aims to provide a confined atmosphere annealing process free of added hydrogen.
- An additional object of the invention is to prevent the selective oxidation of alloying elements in the outermost layer of the surface of the strip during the total oxidation step during continuous annealing. previous cooling and immersion in the zinc bath.
- the present invention relates to a method of continuous annealing and preparation of a high strength steel strip for hot dip coating in a bath of molten metal.
- said steel strip is treated in at least two sections, comprising successively, considering the direction of progression of the strip: a so-called heating and holding section, in which a heating of the strip is achieved; strip followed by maintaining at a given annealing temperature under an oxidizing atmosphere comprising an air (or oxygen) / non-oxidizing or inert gas mixture, in order to form on the surface of the strip a thin oxide film of which the thickness, preferably between 0.02 and 0.
- a so-called cooling and transfer section in which, before it is transferred to the coating bath, at least the annealed strip is cooled and undergoes a complete reduction in iron metal of the iron oxide present in the oxide layer; formed in the heating and holding section, under a reducing atmosphere comprising a mixture of low hydrogen content and inert gas, the said two sections being separated from each other by a conventional airlock; characterized in that the oxidizing atmosphere is at least partially separated from the reducing atmosphere by maintaining a controlled oxygen content in the heating and holding section between 50 and 1000 ppm and in that maintains a controlled hydrogen content in the cooling section and transfer to a value of less than 4% and preferably less than 0.5%.
- the controlled oxygen content is maintained in the heating and holding section between 50 and 400 ppm.
- the separation of the oxidizing atmosphere from the reducing atmosphere is carried out by an overpressure of the oxidizing atmosphere, so that the oxygen entrained by the strip in the cooling zone and transfer through the airlock, following this overpressure, react completely with the hydrogen contained in the cooling atmosphere by forming steam.
- the hydrogen is allowed to react, present in the cooling and transfer section, entrained in the hot gas stream directed upstream, with oxygen from the heating and holding section to form water vapor.
- the cooling and transfer section is maintained in overpressure with respect to the heating and holding section.
- the control of the oxygen content of the oxide layer formed in the heating and holding section is obtained either by modifying the gaseous mixture containing combustion air supplying the flame heating means. direct, or by controlled injection of the mixture air (or oxygen) / inert gas in the case of radiation heating or induction.
- the non-oxidizing or inert gas is nitrogen or argon.
- the liquid metal is zinc or one of its alloys.
- the heating zone and maintenance is devoid of reducing atmosphere.
- the hot dip coating process is a galvanization or a galvannealing treatment.
- the atmosphere both in the heating and holding section and in the cooling and transfer section has a dew point less than or equal to -10 0 C, preferably -20 0 C.
- the strip is heated to a temperature between -10 0 C, preferably -20 0 C.
- the band is then cooled down to a maximum of ⁇
- An economical method proposed according to the invention, aims at carrying out the annealing step preparatory to galvanizing, without the addition of hydrogen, gas which is ten times more expensive than a more common gas such as nitrogen and which is also causing serious fragility defects of resistance steels.
- the invention aims to obtain a perfect galvanization for all grades of steel resistance. To avoid oxidation of the alloy elements at the extreme surface, it is proposed to inject an air / nitrogen mixture into the oven during the entire cycle of (pre-) heating and holding the sheet at high temperature.
- This method therefore does not require atmospheric separation throughout the heating / maintenance portion as is the case in other processes (eg JP-A-2003/342645) where reactive zones in depression are included at this part of the. oven.
- the oxygen contained in the air / nitrogen mixture will have the effect of creating in the annealing section two simultaneous and competitive reactions:
- the alloying elements also contribute to the reduction of iron oxide when they migrate to the steel / iron oxide interface.
- the air / nitrogen atmosphere of the heating / holding portion will have to be separated and partially isolated from the non-oxidizing atmosphere of the cooling and transfer stages of the strip into the zinc bath.
- the oxidizing atmosphere will preferably be maintained at an excess pressure relative to the non-oxidizing atmosphere such that the oxygen entrained by the sheet reacts completely with the hydrogen contained in the atmosphere of the cooling.
- a steel containing, for example, 1.2% of aluminum will for example be heated and annealed to a temperature of 800 ° C. in an atmosphere containing 100 ppm of oxygen in nitrogen.
- the sheet is cooled to 500 ° C. at a speed of 50 ° C./s in an atmosphere containing 4% of hydrogen and 0.1% of water vapor. which corresponds to a dew point of -2O 0 C.
- This sheet is then introduced at the temperature of 470 0 C in a zinc bath, containing 0.2% of aluminum, which is maintained at 46O 0 C. After immersion of 3 seconds, the coating is wrung out so as to keep a zinc layer of 8 ⁇ m. Such a zinc deposit is then perfectly wetting and has adhesion qualities comparable to that obtained for ordinary low-carbon steel.
- Another way to proceed is to allow the usual flow to establish from the zinc bath to the heating section and to leave the very low hydrogen content ( ⁇ 0.5%), contained in the transfer section. / cooling, react with the oxygen of the heating / holding portion to form water vapor.
- An additional supply of oxygen, at the exit of the holding section, can be made to neutralize the entry of hydrogen, the contents used being always located very far from the dangerous, that is to say, explosive ( 4% H 2 in air).
- a high hydrogen content is indeed not necessary in the cooling section because the carbon steel will be sufficient to reduce the thin layer of iron oxide created in the heating / holding part and the metal iron thus prepared will ensure good wettability by the zinc during the immersion of the sheet in the bath.
- this method should provide for controlling the oxygen content in the oven within the range of between 50 and 1000 ppm.
- a content that is too low will not make it possible to produce a layer of iron oxide sufficiently impervious to the diffusion of the alloying elements towards the extreme surface, and a content that is too high in oxygen will produce a layer of iron oxide that is too thick. , which can not be reduced during the cooling and transfer steps to the zinc bath.
- This oxygen content will preferably be in the range of 50 to 400 ppm.
- the invention has a number of advantages, including the fact that: - that hydrogen addition is much lower than in the state of the art, or even zero, in the zone of maintenance-heating, which constitutes an important economy of exploitation and guarantees the obtaining of high strength steel with fewer frailty defects;
- the gaseous atmosphere used is less fragile for the equipment (for example the radiant tubes), in particular following the reduction of the content thereof in hydrogen.
Abstract
The present application relates to a method for continuously annealing and preparing a strip of high-strength steel for the purpose of hot-dip coating it in a bath of liquid metal, in which said steel strip is treated in at least two sections, comprising in succession, when considering the direction of advance of the strip: a section called the heating and holding section, in which the strip is heated and then held at a given annealing temperature in an oxidizing atmosphere; and a section called the cooling and transfer section, in which the annealed strip at least is cooled and undergoes complete reduction, in a reducing atmosphere, of the iron oxide present in the oxide layer formed in the previous section, in such a way that the oxidizing atmosphere is separated from the reducing atmosphere, a controlled oxygen content is maintained in the heating and holding section between 50 and 1000 ppm, and a controlled hydrogen content is maintained in the cooling and transfer section at a value of less than 4% and preferably less than 0.5%.
Description
PROCEDE DE RECUIT ET PREPARATION EN CONTINU D7UNE BAM)E EN ACIER A HAUTE RESISTANCE EN VUE DE SA GALVANISATION AUSTRESS AND PREPARATION PROCESS FOR CONTINUOUSLY 7 A BAM) E HIGH STRENGTH STEEL FOR IN ITS GALVANIZING
TREMPEQUENCH
Objet de l'inventionObject of the invention
[0001] La présente invention se rapporte à un nouveau procédé de recuit et préparation en continu d'une bande en acier à haute résistance en vue de son revêtement au trempé à chaud dans un bain de métal liquide, de préférence une galvanisation ou un . traitement dit de « galvannealing ». [0002] Le domaine technique considéré ici est celui de la galvanisation par défilement continu, dans un bain de revêtement composé de zinc ou d'alliage de zinc, de bandes d'aciers . fortement chargés en éléments d'alliage, plus particulièrement d'aciers HSS (high strength steels) . Ces aciers spéciaux réputés difficiles à galvaniser sont par exemple des aciers pouvant contenir des teneurs en éléments d'alliage (aluminium, manganèse, silicium, chrome, etc.) allant jusqu'à.2 % ou au-delà, des "aciers inoxydables, « dual phase », TRIP, TWIP- (jusqu'à 25 % Mn et 3 % Al), etc. Ces bandes d'acier sont en général destinées à une découpe et mise en forme ultérieure par emboutissage, pliage, etc., en vue d'applications par exemple dans le secteur de l'automobile ou de la construction.
Etat de la techniqueThe present invention relates to a new annealing process and continuous preparation of a high-strength steel strip for its coating by hot quenching in a bath of liquid metal, preferably a galvanization or a. so-called "galvannealing" treatment. The technical field considered here is that of galvanization by continuous scrolling in a coating bath composed of zinc or zinc alloy strips of steel. heavily loaded with alloying elements, especially HSS steels (high strength steels). These special steels known to be difficult to galvanize are, for example, steels which may contain levels of alloying elements (aluminum, manganese, silicon, chromium, etc.) up to . 2% or above, " stainless steels," dual phase ", TRIP, TWIP- (up to 25% Mn and 3% Al), etc. These steel strips are generally intended for cutting and placing in subsequent form by stamping, folding, etc., for applications for example in the automotive or construction sector. State of the art
[0003] II est bien connu que certains aciers ne répondent pas bien à la galvanisation ou au traitement de galvannealing, compte tenu de leur rëactivité superficielle spécifique. Le pouvoir de galvanisation dépend essentiellement de la bonne élimination des résidus d'huile de laminage et de la prévention d'une oxydation superficielle excessive avant immersion dans le bain de métal liquide. Ainsi, un manque de mouillabilité du zinc liquide sur des nuances d'aciers fortement chargées en éléments d'alliage peut être rencontré au cours du procédé de galvanisation en continu. Cette diminution de mouillage du zinc s'explique par la présence d'une couche d'oxydes sélectifs dans la couche externe de la surface de la bande (« extrême surface ») . Ces oxydes sélectifs sont créés par la ségrégation des éléments d'alliage et leur oxydation par la vapeur d'eau, au cours du recuit continu précédent l'immersion dans le bain de zinc. La vapeur d'eau est générée à cet endroit par la réduction de l'oxyde de fer, toujours présent sur la tôle laminée à froid, par l'hydrogène contenu dans l'atmosphère des fours de recuit. [0004] Dès lors, on a cherché à supprimer l'oxydation sélective en mode externe ou à la faire migrer à l'intérieur de l'acier, à 1 ou 2 μm sous la couche externe de la surface, pour permettre de présenter au zinc liquide une couche de fer métallique pratiquement pur, indépendamment de la composition d'alliage et favorisant l'accrochage du revêtement de zinc ou d'alliage de zinc. Ce résultat peut être obtenu par différents procédés : - augmentation du point de rosée pendant le maintien a haute température (par exemple JP-A-2005/068493) , de manière à faire basculer l'oxydation sélective des éléments d'alliage du mode externe au mode interne ;
- oxydation totale du fer pendant l'étape de chauffe, en augmentant par exemple le rapport air/gaz combustible dans les brûleurs du four à flammes directes, puis réduction en fer métallique pendant le maintien à haute température par l'hydrogène (par exemple JP-A-It is well known that some steels do not respond well to galvanizing or galvannealing treatment, given their specific surface reactivity. The galvanizing power essentially depends on the proper removal of the rolling oil residues and the prevention of excessive surface oxidation prior to immersion in the liquid metal bath. Thus, a lack of wettability of liquid zinc on steel grades heavily loaded with alloying elements can be encountered during the continuous galvanizing process. This decrease in zinc wetting is explained by the presence of a layer of selective oxides in the outer layer of the surface of the strip ("extreme surface"). These selective oxides are created by the segregation of the alloying elements and their oxidation by water vapor, during the continuous annealing prior to immersion in the zinc bath. The water vapor is generated here by the reduction of the iron oxide, always present on the cold-rolled sheet, by the hydrogen contained in the atmosphere of the annealing furnaces. [0004] Therefore, it has been sought to eliminate the selective oxidation in external mode or to make it migrate inside the steel, at 1 or 2 μm under the outer layer of the surface, to make it possible to present the zinc liquid a layer of substantially pure metal iron, regardless of the alloy composition and promoting the attachment of zinc coating or zinc alloy. This result can be obtained by various processes: - increase of the dew point during the maintenance at high temperature (for example JP-A-2005/068493), so as to switch the selective oxidation of the alloy elements of the external mode internal mode; total oxidation of the iron during the heating step, for example by increasing the air / fuel gas ratio in the burners of the direct flame furnace, then reduction in metallic iron during the maintenance at high temperature by hydrogen (for example JP -AT-
2005/023348, JP-A-07 034210, etc.) ou réduction par le2005/023348, JP-A-07 034210, etc.) or reduction by the
• carbone libre de l'acier gui diffuse, le cas échéant, au travers de la couche d'oxyde et échange de l'oxygène à la surface de celle-ci (voir par exemple BE-A-I 014 997) ;• free carbon steel mistletoe diffuses, if necessary, through the oxide layer and exchange of oxygen on the surface thereof (see for example BE-A-I 014 997);
- pré-dépôt de fer ou de nickel (par exemple JP-A- 04 280925, JP-A-2005/105399) .pre-deposition of iron or nickel (for example JP-A-04 280925, JP-A-2005/105399).
[0005] Ces procédés imposent généralement de travailler en atmosphère réductrice pour l'acier pendant la phase de maintien a haute température, nécessitant un 'bas point de rosée et une teneur élevée en hydrogène (jusqu'à 75 % du gaz d'atmosphère) qui est un gaz coûteux. Ils permettent tous d'améliorer la « galvanisabilité » des aciers de haute résistance avec une efficacité significative mais cependant insuffisante, surtout dans le cas de certains aciers contenant par exemple des teneurs importantes en silicium (environ 1,5 % en poids). Par ailleurs, les procédés nécessitant un pré-dépôt présentent des coûts très élevés. [0006] Selon un exemple de procédé déjà connu dans l'état de l'art, une installation de recuit et préparation d'une bande d'acier pour la galvanisation comprend typiquement, dans le sens de progression de la bande :These processes generally require working in a reducing atmosphere for the steel during the high temperature maintenance phase, requiring a low dew point and a high hydrogen content (up to 75% of the atmosphere gas). which is an expensive gas. They all make it possible to improve the "galvanizability" of high strength steels with a significant but insufficient efficiency, especially in the case of certain steels containing, for example, significant silicon contents (approximately 1.5% by weight). Moreover, the processes requiring a pre-deposit have very high costs. According to an example of a method already known in the state of the art, an annealing installation and preparation of a steel strip for galvanizing typically comprises, in the direction of progression of the strip:
- une première section de (pré) chauffage assurant le chauffage de la bande jusqu'à une température permettant la formation d'un film d'oxyde d'épaisseur adéquate (environ 50 nanomètres) pour sa réduction ultérieure ; cette section se trouve sous une atmosphère rendue oxydante par adjonction d'air ou d'oxygène, par exemple
sous la forme d'un' mélange air/gaz combustible dans le cas d'un four à flamme directe ou d'air seul dans le- cas d'un four radiant ;a first (pre) heating section heating the strip to a temperature allowing the formation of an oxide film of adequate thickness (about 50 nanometers) for its subsequent reduction; this section is under an oxidizing atmosphere by adding air or oxygen, for example in the form of an air / fuel mixture gas in the case of a direct flame furnace or air alone in le case of a radiant furnace;
- une deuxième section de recuit, séparée de la section de chauffage par un sas conventionnel, où la bande est maintenue à la haute température de recuit et qui se trouve sous une atmosphère inerte en surpression, pour y empêcher l'entrée des gaz de la section de chauffe ;a second annealing section, separated from the heating section by a conventional airlock, where the strip is kept at the high annealing temperature and which is under an inert atmosphere at overpressure, to prevent the entry of gases from the heating section;
- une troisième section de réduction, également séparée de la deuxième section par un sas conventionnel, sous une atmosphère en légère dépression par rapport à celle-ci mais en légère surpression par rapport à l'ambiante ; cette section est destinée à terminer le cycle de recuita third reduction section, also separated from the second section by a conventional airlock, under an atmosphere slightly depressed with respect thereto but at a slight overpressure with respect to the ambient; this section is intended to finish the annealing cycle
(fin de la période de maintien) , à refroidir la bande et éventuellement à effectuer un survieillissement avant de la transférer dans le bain de métal liquide via une trompe d'immersion ; dans cette zone, la couche d'oxyde créée dans la première section est idéalement réduite complètement par une atmosphère hydrogène/gaz inerte à très bas point de rosée.(end of the holding period), to cool the band and possibly to carry out a survival before transferring it into the bath of liquid metal via an immersion tube; in this zone, the oxide layer created in the first section is ideally reduced completely by a hydrogen / inert gas atmosphere with a very low dew point.
[0007] Bien entendu, on connaît aussi des fours de recuit plus simples ou plus complexes, comprenant typiquement entre une et quatre sections distinctes, pour réaliser les fonctions respectives de (pré-) chauffe, maintien, refroidissement, survieillissement, etc.Of course, there are also known simpler or more complex annealing furnaces, typically comprising between one and four distinct sections, to perform the respective functions of (pre-) heating, maintenance, cooling, over-aging, etc.
Buts de 1 ' inventionAims of the invention
[0008] La présente invention vise à fournir une solution qui permette de s'affranchir des .inconvénients de l'état de la technique.The present invention aims to provide a solution that makes it possible to overcome the disadvantages of the state of the art.
[0009] En particulier, l'invention vise à fournir un procédé de recuit et préparation en vue d'une galvanisation d'aciers de haute résistance qui soit plus économique,
cette dernière étant effectuée avec ou sans traitement thermique d'accompagnement de type galvannealing. [0010] L'invention a encore pour but de permettre une préparation d'aciers de haute résistance pour la galvanisation, qui soient exempts de défauts de fragilité. [0011] En particulier, l'invention a pour but de fournir un procédé de recuit sous atmosphère confinée exempte d'hydrogène ajouté. [0012] Un but complémentaire de l'invention est d'empêcher l'oxydation sélective d'éléments d'alliage dans la couche la plus externe de la surface de la bande au cours de l'étape d'oxydation totale lors du recuit continu précédent le refroidissement et l'immersion dans le bain de zinc .In particular, the invention aims to provide a method of annealing and preparation for galvanizing high strength steels which is more economical, the latter being carried out with or without accompanying heat treatment galvannealing type. The invention also aims to allow a preparation of high strength steels for galvanizing, which are free of brittleness defects. In particular, the invention aims to provide a confined atmosphere annealing process free of added hydrogen. An additional object of the invention is to prevent the selective oxidation of alloying elements in the outermost layer of the surface of the strip during the total oxidation step during continuous annealing. previous cooling and immersion in the zinc bath.
Principaux éléments caractéristiques de l'invention [0013] La présente invention se rapporte à un procédé de recuit et de préparation en continu d'une bande en acier de haute résistance, en vue de son revêtement au trempé à chaud dans un bain de métal liquide, selon lequel on traite ladite bande d'acier dans au moins deux sections, comprenant successivement, si l'on considère le sens de progression de la bande : - une section dite de chauffe et de maintien, dans laquelle est réalisé un chauffage de la bande suivi d'un maintien à une température donnée de recuit sous une atmosphère oxydante comprenant un mélange air (ou oxygène) /gaz non oxydant ou inerte, en vue de former sur la surface de la bande un fin film d'oxyde dont l'épaisseur, comprise de préférence entre 0,02 et 0., 2 μm, est contrôlée, ledit chauffage de la bande étant • effectué soit par flamme directe, soit par rayonnement ;
- une .section dite de refroidissement et de transfert, dans laquelle, avant son transfert au bain de revêtement, la bande recuite au moins est refroidie et subit une réduction complète en fer métallique de l'oxyde de fer présent dans la couche d'oxyde formée dans la section de chauffe et de maintien, sous une atmosphère réductrice comprenant un mélange à basse teneur en hydrogène et gaz inerte, les deux dites sections étant séparées l'une de l'autre par un sas conventionnel ; caractérisé en ce qu'on sépare au moins partiellement l'atmosphère oxydante de l'atmosphère réductrice, en ce qu'on maintient une teneur en oxygène contrôlée dans la section de chauffe et de maintien entre 50 et 1000 ppm et en ce qu'on maintient une teneur en hydrogène contrôlée dans la section de refroidissement et transfert à une valeur inférieure à 4 % et de préférence inférieure à 0,5 %.Main Features of the Invention [0013] The present invention relates to a method of continuous annealing and preparation of a high strength steel strip for hot dip coating in a bath of molten metal. according to which said steel strip is treated in at least two sections, comprising successively, considering the direction of progression of the strip: a so-called heating and holding section, in which a heating of the strip is achieved; strip followed by maintaining at a given annealing temperature under an oxidizing atmosphere comprising an air (or oxygen) / non-oxidizing or inert gas mixture, in order to form on the surface of the strip a thin oxide film of which the thickness, preferably between 0.02 and 0. 2 microns, is controlled, said heating of the strip being performed • either by direct flame or by radiation; a so-called cooling and transfer section, in which, before it is transferred to the coating bath, at least the annealed strip is cooled and undergoes a complete reduction in iron metal of the iron oxide present in the oxide layer; formed in the heating and holding section, under a reducing atmosphere comprising a mixture of low hydrogen content and inert gas, the said two sections being separated from each other by a conventional airlock; characterized in that the oxidizing atmosphere is at least partially separated from the reducing atmosphere by maintaining a controlled oxygen content in the heating and holding section between 50 and 1000 ppm and in that maintains a controlled hydrogen content in the cooling section and transfer to a value of less than 4% and preferably less than 0.5%.
[0014] II faut entendre par réduction complète de l'oxyde de fer, une réduction de celui-ci à au moins 98 %. [0015] Avantageusement, on maintient la teneur en oxygène contrôlée dans la section de chauffe et de maintien entre 50 et 400 ppm.It is meant by complete reduction of iron oxide, a reduction thereof to at least 98%. Advantageously, the controlled oxygen content is maintained in the heating and holding section between 50 and 400 ppm.
[0016] Selon une première modalité préférée de réalisation de l'invention, la séparation de l'atmosphère oxydante de l'atmosphère réductrice est réalisée par une surpression .de l'atmosphère oxydante, pour que l'oxygène entraîné par la bande dans la zone de refroidissement et transfert à travers le sas, suite à cette surpression, réagisse complètement avec l'hydrogène contenu dans l'atmosphère de refroidissement en formant de la vapeur d' eau.According to a first preferred embodiment of the invention, the separation of the oxidizing atmosphere from the reducing atmosphere is carried out by an overpressure of the oxidizing atmosphere, so that the oxygen entrained by the strip in the cooling zone and transfer through the airlock, following this overpressure, react completely with the hydrogen contained in the cooling atmosphere by forming steam.
[0017] Selon une deuxième modalité préférée de réalisation de l'invention, on laisse réagir l'hydrogène,
présent dans la section de refroidissement et transfert, entraîné dans le flux gazeux chaud dirigé vers l'amont, avec l'oxygène provenant de la section de chauffe et de maintien pour former de la vapeur d'eau. Dans ce cas, la section de refroidissement et transfert est maintenue en surpression par rapport à la section de chauffe et maintien. Comme le gaz en surpression ne peut s'échapper vers le bain de métal liquide, il remonte en effet vers la zone de chauffe et maintien. [0018] Selon l'invention, le contrôle du contenu en oxygène de la couche d'oxyde formée dans la section de chauffe et de maintien est obtenu soit par modification du mélange gazeux contenant de l'air comburant alimentant des moyens de chauffage par flamme directe, soit par injection contrôlée du mélange air (ou oxygène) /gaz inerte dans le cas d'un chauffage par rayonnement ou induction. [0019] De préférence, le gaz non oxydant ou inerte est l'azote ou l'argon. [0020] Avantageusement, le métal liquide est le zinc ou un de ses alliages.According to a second preferred embodiment of the invention, the hydrogen is allowed to react, present in the cooling and transfer section, entrained in the hot gas stream directed upstream, with oxygen from the heating and holding section to form water vapor. In this case, the cooling and transfer section is maintained in overpressure with respect to the heating and holding section. As the gas under pressure can not escape to the bath of liquid metal, it goes back to the heating and maintenance zone. According to the invention, the control of the oxygen content of the oxide layer formed in the heating and holding section is obtained either by modifying the gaseous mixture containing combustion air supplying the flame heating means. direct, or by controlled injection of the mixture air (or oxygen) / inert gas in the case of radiation heating or induction. [0019] Preferably, the non-oxidizing or inert gas is nitrogen or argon. [0020] Advantageously, the liquid metal is zinc or one of its alloys.
[0021] Toujours avantageusement, la zone de chauffe et maintien est dépourvue d'atmosphère réductrice. [0022] De préférence, le procédé de revêtement au trempé à chaud est une galvanisation ou un traitement de galvannealing .Still advantageously, the heating zone and maintenance is devoid of reducing atmosphere. Preferably, the hot dip coating process is a galvanization or a galvannealing treatment.
[0023] Toujours selon l'invention, l'atmosphère tant dans la section de chauffe et de maintien que dans la section de refroidissement et de transfert a un point de rosée inférieur ou égal à -100C, de préférence à -200C. [0024] Selon une modalité opérationnelle préférée, l'on chauffe la bande à une température comprise entreStill according to the invention, the atmosphere both in the heating and holding section and in the cooling and transfer section has a dew point less than or equal to -10 0 C, preferably -20 0 C. [0024] According to a preferred operational mode, the strip is heated to a temperature between
65O0C et 12000C, en ce compris la température de maintien.65O 0 C and 1200 0 C, including the holding temperature.
[0025] Selon une autre modalité opérationnelle préférée, l'on refroidit ensuite la bande jusqu'à une
δAccording to another preferred operational mode, the band is then cooled down to a maximum of δ
température supérieure à 450°C, avec une vitesse de refroidissement comprise entre 10 et 100°C/s.temperature above 450 ° C, with a cooling rate between 10 and 100 ° C / s.
Description d'une forme d'exécution préférée de l'invention [0026] Un procédé économique, proposé selon l'invention, vise à réaliser l'étape de recuit préparatoire à la galvanisation, sans ajout d'hydrogène, gaz qui est dix fois plus cher qu'un gaz plus commun tel que l'azote et qui est cause en outre de graves défauts de fragilité des aciers de résistance.DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION An economical method, proposed according to the invention, aims at carrying out the annealing step preparatory to galvanizing, without the addition of hydrogen, gas which is ten times more expensive than a more common gas such as nitrogen and which is also causing serious fragility defects of resistance steels.
[0027] L'invention vise à obtenir une galvanisation parfaite pour toutes les nuances d'acier de résistance. Pour éviter l'oxydation des éléments d'alliage en extrême surface, il est proposé d'injecter un mélange air/azote dans le four pendant tout le cycle de (pré-) chauffage et de maintien de la tôle à haute température.The invention aims to obtain a perfect galvanization for all grades of steel resistance. To avoid oxidation of the alloy elements at the extreme surface, it is proposed to inject an air / nitrogen mixture into the oven during the entire cycle of (pre-) heating and holding the sheet at high temperature.
[0028] Ce procédé ne nécessite donc pas de séparation d'atmosphère dans toute la partie chauffe/maintien comme cela est le cas dans d'autres procédés (par exemple JP-A-2003/342645) où des zones réactives en dépression sont incluses au niveau de cette partie du. four.This method therefore does not require atmospheric separation throughout the heating / maintenance portion as is the case in other processes (eg JP-A-2003/342645) where reactive zones in depression are included at this part of the. oven.
[0029] L'oxygène contenu dans le mélange air/azote aura pour effet de créer dans la section de recuit deux réactions simultanées et compétitives :The oxygen contained in the air / nitrogen mixture will have the effect of creating in the annealing section two simultaneous and competitive reactions:
- l'oxydation du fer par l'oxygène en extrême surface avec croissance de l'oxyde de fer par diffusion de fer en surface. Ainsi, tant qu'une fine couche d'oxyde de fer subsiste en surface de la tôle, les éléments d'alliage, à l'exception du manganèse, sont bloqués à l'interface acier/oxyde de fer ;the oxidation of iron by oxygen at the extreme surface with growth of iron oxide by diffusion of iron at the surface. Thus, as long as a thin layer of iron oxide remains on the surface of the sheet, the alloying elements, with the exception of manganese, are blocked at the steel / iron oxide interface;
- la réduction subséquente de l'oxyde de fer par diffusion du carbone libre vers l'interface acier/oxyde de fer.
[0030] Les éléments d'alliage participent également à la réduction de l'oxyde de fer lorsqu'ils migrent à l'interface acier/oxyde de fer.the subsequent reduction of the iron oxide by diffusion of the free carbon towards the steel / iron oxide interface. The alloying elements also contribute to the reduction of iron oxide when they migrate to the steel / iron oxide interface.
[0031] L'atmosphère air/azote de la partie chauffe/maintien devra toutefois être séparée et partiellement isolée de l'atmosphère non oxydante des étapes de refroidissement et de transfert de la bande jusque dans le bain de zinc. Pour ce faire, l'atmosphère oxydante sera, de préférence, maintenue en surpression par rapport à l'atmosphère non oxydante de telle manière que l'oxygène entraîné par la tôle réagisse complètement avec l'hydrogène contenu dans l'atmosphère de la section de refroidissement . [0032] Dans une telle configuration, un acier contenant entre autres 1,2 % d'aluminium sera par exemple chauffé et recuit jusqu'à une température de 8000C dans une atmosphère contenant 100 ppm d'oxygène dans de l'azote. A la fin du maintien qui dure une minute, la tôle est refroidie jusqu'à 5000C à une vitesse de 50°C/s dans une atmosphère contenant 4 % d'hydrogène et 0,1 % de vapeur d'eau, ce qui correspond à un point de rosée de -2O0C.However, the air / nitrogen atmosphere of the heating / holding portion will have to be separated and partially isolated from the non-oxidizing atmosphere of the cooling and transfer stages of the strip into the zinc bath. For this purpose, the oxidizing atmosphere will preferably be maintained at an excess pressure relative to the non-oxidizing atmosphere such that the oxygen entrained by the sheet reacts completely with the hydrogen contained in the atmosphere of the cooling. In such a configuration, a steel containing, for example, 1.2% of aluminum will for example be heated and annealed to a temperature of 800 ° C. in an atmosphere containing 100 ppm of oxygen in nitrogen. At the end of the hold which lasts one minute, the sheet is cooled to 500 ° C. at a speed of 50 ° C./s in an atmosphere containing 4% of hydrogen and 0.1% of water vapor. which corresponds to a dew point of -2O 0 C.
Cette tôle est ensuite introduite à la température de 4700C dans un bain de zinc, contenant 0,2 % d'aluminium, qui est maintenu à 46O0C. Après une immersion de 3 secondes, le revêtement est essoré de manière à garder une couche de zinc de 8 μm. Un tel dépôt de zinc est alors parfaitement mouillant et présente des qualités d'adhérence comparables à celle obtenue pour un acier à bas carbone ordinaire.This sheet is then introduced at the temperature of 470 0 C in a zinc bath, containing 0.2% of aluminum, which is maintained at 46O 0 C. After immersion of 3 seconds, the coating is wrung out so as to keep a zinc layer of 8 μm. Such a zinc deposit is then perfectly wetting and has adhesion qualities comparable to that obtained for ordinary low-carbon steel.
[0033] Pour citer un autre exemple, le même procédé pourra être appliqué sur un acier contenant entre autresTo cite another example, the same process can be applied to a steel containing inter alia
1,5 % de silicium. Dans ce cas toutefois, il faudra augmenter la teneur en oxygène pendant d'étape de chauffe / maintien à 300 ppm pour obtenir un résultat comparable. Cette augmentation de la teneur en oxygène est nécessaire
car le silicium freine la diffusion du fer en assurant une barrière d'oxyde de silicium à l'interface acier / oxyde de fer.1.5% silicon. In this case, however, it will be necessary to increase the oxygen content during the heating / holding step to 300 ppm to obtain a comparable result. This increase in oxygen content is necessary because silicon slows the diffusion of iron by providing a silicon oxide barrier at the steel / iron oxide interface.
[0034] Une autre manière de procéder est de laisser le flux habituel s'établir depuis le bain de zinc vers la section de chauffe et de laisser la très faible teneur en hydrogène (<0,5 %) , contenue dans la section de transfert/refroidissement, réagir avec l'oxygène de la partie chauffe/maintien pour former de la vapeur d'eau. Un apport supplémentaire en oxygène, à la sortie de la section de maintien, pourra être fait pour neutraliser l'entrée d'hydrogène, les teneurs mises en œuvre étant toujours situées très loin du domaine dangereux, c'est-à-dire explosif (4 % H2 dans l'air) . [0035] Une teneur élevée en hydrogêne n'est en effet pas nécessaire dans la section de refroidissement car le carbone de l'acier sera suffisant pour réduire la fine couche d'oxyde de fer créée dans la partie chauffe/maintien et le fer métallique ainsi préparé assurera une bonne mouillabilité par le zinc lors de l'immersion de la tôle dans le bain.Another way to proceed is to allow the usual flow to establish from the zinc bath to the heating section and to leave the very low hydrogen content (<0.5%), contained in the transfer section. / cooling, react with the oxygen of the heating / holding portion to form water vapor. An additional supply of oxygen, at the exit of the holding section, can be made to neutralize the entry of hydrogen, the contents used being always located very far from the dangerous, that is to say, explosive ( 4% H 2 in air). A high hydrogen content is indeed not necessary in the cooling section because the carbon steel will be sufficient to reduce the thin layer of iron oxide created in the heating / holding part and the metal iron thus prepared will ensure good wettability by the zinc during the immersion of the sheet in the bath.
[0036] Pour être efficace, ce procédé devra prévoir de contrôler la teneur en oxygène dans le four à l'intérieur de l'intervalle compris entre 50 et 1000 ppm. En effet une teneur trop faible ne permettra pas de réaliser une couche d'oxyde de fer suffisamment étanche à la diffusion des éléments d'alliage vers l'extrême surface et une teneur trop élevée en oxygène produira une couche d'oxyde de fer trop épaisse, qui ne pourra pas être réduite au cours des étapes de refroidissement et de transfert vers le bain de zinc. Cette teneur en oxygène sera de préférence située dans une fourchette de 50 à 400 ppm.To be effective, this method should provide for controlling the oxygen content in the oven within the range of between 50 and 1000 ppm. In fact, a content that is too low will not make it possible to produce a layer of iron oxide sufficiently impervious to the diffusion of the alloying elements towards the extreme surface, and a content that is too high in oxygen will produce a layer of iron oxide that is too thick. , which can not be reduced during the cooling and transfer steps to the zinc bath. This oxygen content will preferably be in the range of 50 to 400 ppm.
[0037] L'invention présente un certain nombre d'avantages, dont notamment le fait :
— qu'on procède à un ajout d'hydrogène beaucoup plus faible que dans l'état de la technique, voire nul, dans la zone de chauffe-maintien, ce qui constitue une importante économie d'exploitation et garantit l'obtention d'acier de haute résistance présentant moins de défauts de fragilité ;The invention has a number of advantages, including the fact that: - that hydrogen addition is much lower than in the state of the art, or even zero, in the zone of maintenance-heating, which constitutes an important economy of exploitation and guarantees the obtaining of high strength steel with fewer frailty defects;
- qu'on ne sépare plus la section de chauffe de la section de maintien à la température de recuit, ce qui permet d'économiser un sas ainsi que d'éviter éventuellement un dédoublement des équipements de contrôle de l'atmosphère gazeuse ;- It no longer separates the heating section of the holding section at the annealing temperature, which saves an airlock and possibly avoid duplication of gaseous atmosphere control equipment;
— que ce procédé est beaucoup plus efficace que les procédés connus dans l'état de la technique, du point de vue de l'adhérence du revêtement ou de la mouillabilité de la bande ;That this method is much more effective than the processes known in the state of the art, from the point of view of the adhesion of the coating or the wettability of the strip;
- que l'atmosphère gazeuse utilisée est moins fragilisante pour l'équipement (par exemple les tubes radiants), notamment suite à la réduction de la teneur de celle-ci en hydrogène .
the gaseous atmosphere used is less fragile for the equipment (for example the radiant tubes), in particular following the reduction of the content thereof in hydrogen.
Claims
1. Procédé de recuit et de préparation en continu d'une bande en acier de haute résistance, en vue de son revêtement au trempé à chaud dans un bain de métal liquide, selon lequel on traite ladite bande d'acier dans au moins deux sections, comprenant successivement, si l'on considère le sens de progression de la bande :A method of continuously annealing and preparing a high strength steel strip for hot dip coating in a bath of molten metal, wherein said steel strip is treated in at least two sections , comprising successively, if we consider the direction of progression of the band:
- une section dite de chauffe et de maintien, dans laquelle est réalisé un chauffage de la bande suivi d'un maintien à une température donnée de recuit sous une atmosphère oxydante comprenant un mélange air (ou oxygène) /gaz non oxydant ou inerte, en vue de former sur la surface de la bande un fin film d'oxyde dont l'épaisseur, comprise de préférence entre 0,02 et 0,2 μm, est contrôlée, ledit chauffage de la bande étant effectué soit par flamme directe, soit par rayonnement ;a so-called heating and holding section, in which heating of the strip is carried out followed by maintenance at a given annealing temperature under an oxidizing atmosphere comprising an air (or oxygen) / non-oxidizing or inert gas mixture, to form on the surface of the strip a thin oxide film whose thickness, preferably between 0.02 and 0.2 μm, is controlled, said heating of the strip being carried out either by direct flame or by radiation;
- une section dite de refroidissement et de transfert, dans laquelle, avant son transfert au bain de revêtement, la bande recuite au moins est refroidie et subit une réduction complète en fer métallique de l'oxyde de fer présent dans la couche d'oxyde formée dans la section de chauffe et de maintien, sous une atmosphère réductrice comprenant un mélange à basse teneur en hydrogène et gaz inerte, les deux dites sections étant séparées l'une de l'autre par un sas conventionnel ; caractérisé en ce qu'on sépare au moins partiellement l'atmosphère oxydante de l'atmosphère réductrice, en ce qu'on maintient une teneur en oxygène contrôlée dans la section de chauffe et de maintien entre 50 et 1000 ppm et en ce qu'on maintient une teneur en hydrogène contrôlée dans la section de refroidissement et transfert à une valeur inférieure à 4 % et de préférence inférieure à 0,5 %.a so-called cooling and transfer section, in which, before it is transferred to the coating bath, the at least one annealed strip is cooled and undergoes a complete reduction in metallic iron of the iron oxide present in the formed oxide layer; in the heating and holding section, under a reducing atmosphere comprising a mixture of low hydrogen content and inert gas, the said two sections being separated from each other by a conventional airlock; characterized in that the oxidizing atmosphere is at least partially separated from the reducing atmosphere by maintaining a controlled oxygen content in the heating and holding section between 50 and 1000 ppm and in that maintains a controlled hydrogen content in the cooling section and transfer to a less than 4% and preferably less than 0.5%.
2. Procédé selon la revendication 1, caractérisé en ce qu'on maintient la teneur en oxygène contrôlée dans la section de chauffe et de maintien entre 50 et 400 ppm.2. Method according to claim 1, characterized in that maintains the controlled oxygen content in the heating section and maintenance between 50 and 400 ppm.
3. Procédé selon la revendication 1 ou 2, caractérisé en ce que la séparation de l'atmosphère oxydante de l'atmosphère réductrice est réalisée par une surpression de l'atmosphère oxydante, pour que l'oxygène entraîné par la bande à travers le sas réagisse complètement avec l'hydrogène contenu dans l'atmosphère de refroidissement en formant de la vapeur d'eau.3. Method according to claim 1 or 2, characterized in that the separation of the oxidizing atmosphere from the reducing atmosphere is performed by an overpressure of the oxidizing atmosphere, so that the oxygen entrained by the band through the airlock react completely with the hydrogen contained in the cooling atmosphere by forming water vapor.
4. Procédé selon la revendication 1 ou 2, caractérisé en ce qu'on laisse réagir l'hydrogène, présent dans la section de refroidissement et transfert qui est en surpression par rapport à la section de chauffe et de maintien, entraîné dans le flux gazeux chaud dirigé vers l'amont, avec l'oxygène provenant de la section de chauffe et de maintien pour former de la vapeur d'eau.4. Method according to claim 1 or 2, characterized in that hydrogen is allowed to react, present in the cooling and transfer section which is overpressure with respect to the heating and holding section, entrained in the gas stream hot directed upstream, with oxygen from the heating and holding section to form water vapor.
5. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que le contrôle du contenu en oxygène de la couche d'oxyde formée dans la section de chauffe et de maintien est obtenu soit par modification du mélange gazeux contenant de l'air comburant alimentant des moyens de chauffage par flamme directe, soit par injection contrôlée du mélange air (ou oxygène) /gaz inerte dans le cas d'un chauffage par rayonnement ou induction. 5. Method according to any one of the preceding claims, characterized in that the control of the oxygen content of the oxide layer formed in the heating and holding section is obtained either by modifying the gaseous mixture containing air oxidant supplying direct flame heating means, or by controlled injection of the mixture air (or oxygen) / inert gas in the case of radiation heating or induction.
6. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que le gaz non oxydant ou inerte est l'azote ou l'argon. 6. Method according to any one of the preceding claims, characterized in that the non-oxidizing or inert gas is nitrogen or argon.
7. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que le métal liquide est le zinc ou un de ses alliages.7. Method according to any one of the preceding claims, characterized in that the liquid metal is zinc or one of its alloys.
8. Procédé selon la revendication 1, caractérisé en ce que la zone de chauffe et maintien est dépourvue d'atmosphère réductrice.8. Method according to claim 1, characterized in that the heating and maintenance zone is devoid of reducing atmosphere.
9. Procédé selon la revendication 1, caractérisé en ce que le procédé de revêtement au trempé à chaud est une galvanisation ou un traitement de galvannealing .9. The method of claim 1, characterized in that the hot dip coating process is a galvanization or a galvannealing treatment.
10. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que l'atmosphère dans la section de chauffe et de maintien et dans la section de refroidissement et de transfert a un point de rosée inférieur ou égal à -100C, de préférence à - 2O0C.10. Method according to any one of the preceding claims, characterized in that the atmosphere in the heating and holding section and in the cooling and transfer section has a dew point less than or equal to -10 0 C, preferably at -20 ° C.
11. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que l'on chauffe la bande à une température comprise entre 6500C et 12000C, en ce compris la température de maintien.11. Method according to any one of the preceding claims, characterized in that the strip is heated to a temperature between 650 0 C and 1200 0 C, including the holding temperature.
12. Procédé selon la revendication 15, caractérisé en ce que l'on refroidit ensuite la bande jusqu'à une température supérieure à 4500C, avec une vitesse de refroidissement comprise entre 10 et 100°C/s. 12. The method of claim 15, characterized in that the band is then cooled to a temperature above 450 0 C, with a cooling rate of between 10 and 100 ° C / s.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PL07719191T PL1999287T3 (en) | 2006-03-29 | 2007-03-13 | Method for continuously annealing and preparing strip of high-strength steel for the purpose of hot-dip galvanizing it |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE2006/0201A BE1017086A3 (en) | 2006-03-29 | 2006-03-29 | PROCESS FOR THE RECLAIMING AND CONTINUOUS PREPARATION OF A HIGH STRENGTH STEEL BAND FOR ITS GALVANIZATION AT TEMPERATURE. |
| PCT/BE2007/000026 WO2007109865A1 (en) | 2006-03-29 | 2007-03-13 | Method for continuously annealing and preparing strip of high-strength steel for the purpose of hot-dip galvanizing it |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP1999287A1 true EP1999287A1 (en) | 2008-12-10 |
| EP1999287B1 EP1999287B1 (en) | 2009-08-19 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP07719191A Not-in-force EP1999287B1 (en) | 2006-03-29 | 2007-03-13 | Method for continuously annealing and preparing strip of high-strength steel for the purpose of hot-dip galvanizing it |
Country Status (18)
| Country | Link |
|---|---|
| US (1) | US8409667B2 (en) |
| EP (1) | EP1999287B1 (en) |
| JP (1) | JP5140660B2 (en) |
| KR (1) | KR101406789B1 (en) |
| CN (1) | CN101466860B (en) |
| AT (1) | ATE440156T1 (en) |
| AU (1) | AU2007231473B2 (en) |
| BE (1) | BE1017086A3 (en) |
| BR (1) | BRPI0709419A2 (en) |
| CA (1) | CA2644459C (en) |
| DE (1) | DE602007002064D1 (en) |
| ES (1) | ES2331634T3 (en) |
| MX (1) | MX2008012494A (en) |
| PL (1) | PL1999287T3 (en) |
| RU (1) | RU2426815C2 (en) |
| UA (1) | UA92079C2 (en) |
| WO (1) | WO2007109865A1 (en) |
| ZA (1) | ZA200808424B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10400315B2 (en) | 2013-07-04 | 2019-09-03 | ArcelorMittal Investigación y Desarrollo, S.L. | Cold rolled steel sheet and vehicle |
Families Citing this family (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8465806B2 (en) | 2007-05-02 | 2013-06-18 | Tata Steel Ijmuiden B.V. | Method for hot dip galvanizing of AHSS or UHSS strip material, and such material |
| FR2920439B1 (en) * | 2007-09-03 | 2009-11-13 | Siemens Vai Metals Tech Sas | METHOD AND DEVICE FOR THE CONTROLLED OXIDATION / REDUCTION OF THE SURFACE OF A CONTINUOUSLY STRAY STEEL BAND IN A RADIANT TUBE OVEN FOR ITS GALVANIZATION |
| JP2010018874A (en) * | 2008-07-14 | 2010-01-28 | Kobe Steel Ltd | Hot-dip galvannealed steel sheet and production method thereof |
| CN101812578B (en) * | 2009-02-25 | 2012-05-23 | 宝山钢铁股份有限公司 | Flexible strip processing line suitable for producing various high-strength steel |
| DE102009018577B3 (en) | 2009-04-23 | 2010-07-29 | Thyssenkrupp Steel Europe Ag | A process for hot dip coating a 2-35 wt.% Mn-containing flat steel product and flat steel product |
| CN102121089A (en) * | 2011-01-28 | 2011-07-13 | 浙江永丰钢业有限公司 | Reduction annealing and heat plating process of band steel continuous heat plating rare earth aluminium zinc alloy |
| DE102011102659A1 (en) * | 2011-05-27 | 2012-11-29 | ThermProTEC Asia UG (haftungsbeschränkt) | Method and device for pre-oxidizing metal strips |
| DE102011051731B4 (en) * | 2011-07-11 | 2013-01-24 | Thyssenkrupp Steel Europe Ag | Process for the preparation of a flat steel product provided by hot dip coating with a metallic protective layer |
| KR101360734B1 (en) * | 2011-12-28 | 2014-02-10 | 주식회사 포스코 | Galvanized steel sheet having excellent coatibility and coating adhesion and method for manufacturing the same |
| KR101657862B1 (en) * | 2012-04-17 | 2016-09-19 | 제이에프이 스틸 가부시키가이샤 | Method for producing alloyed hot-dip galvanized steel sheet having excellent adhesion to plating and excellent sliding properties |
| JP5655955B2 (en) * | 2012-06-13 | 2015-01-21 | Ｊｆｅスチール株式会社 | Steel strip continuous annealing method, steel strip continuous annealing device, hot dip galvanized steel strip manufacturing method and hot dip galvanized steel strip manufacturing device |
| DE102013105378B3 (en) * | 2013-05-24 | 2014-08-28 | Thyssenkrupp Steel Europe Ag | Process for the preparation of a hot-dip coated flat steel product and continuous furnace for a hot-dip coating machine |
| CN103726003B (en) * | 2013-12-20 | 2015-10-28 | 东北大学 | Pickling hot galvanizing method exempted from by a kind of hot rolled strip based on scale reduction |
| WO2016156125A1 (en) * | 2015-04-02 | 2016-10-06 | Cockerill Maintenance & Ingénierie S.A. | Method and device for reaction control |
| WO2017182833A1 (en) * | 2016-04-19 | 2017-10-26 | Arcelormittal | Method for producing a metallic coated steel sheet |
| CN106119477B (en) * | 2016-08-25 | 2018-07-10 | 华冠新型材料股份有限公司 | For the reducing atmosphere method for building up and continuous annealing process of continuous annealing process |
| CN106435105B (en) * | 2016-12-01 | 2017-12-26 | 浙江东南金属薄板有限公司 | A kind of preparation method of galvanizing coil of strip |
| CN107164624B (en) * | 2017-04-10 | 2020-02-21 | 首钢集团有限公司 | Method for controlling pockmark defects on surface of phosphorus-containing cold-rolled high-strength steel |
| CN107254572B (en) * | 2017-06-01 | 2019-07-02 | 首钢集团有限公司 | A kind of cold-reduced silicon manganese dual-phase steel surface point defects controlling method |
| WO2019171157A1 (en) * | 2018-03-09 | 2019-09-12 | Arcelormittal | A manufacturing process of press hardened parts with high productivity |
| FR3095452A1 (en) * | 2019-04-29 | 2020-10-30 | Fives Stein | Dual Purpose Metal Strip Continuous Processing Line |
| CN111850263B (en) * | 2020-06-22 | 2022-07-26 | 鞍钢蒂森克虏伯汽车钢有限公司 | Production method for improving aging resistance of continuous hot-dip galvanizing baking hardened steel plate |
| CN111850262B (en) * | 2020-06-22 | 2022-07-26 | 鞍钢蒂森克虏伯汽车钢有限公司 | Production method of ultra-low carbon baking hardening continuous hot-dip galvanized steel sheet |
| CN112143992A (en) * | 2020-10-23 | 2020-12-29 | 杭州创力科技服务有限公司 | Temperature-variable oxidation-reduction integrated pretreatment process and treatment device thereof |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3966351A (en) * | 1974-05-15 | 1976-06-29 | Robert Stanley Sproule | Drag reduction system in shrouded turbo machine |
| US3925579A (en) * | 1974-05-24 | 1975-12-09 | Armco Steel Corp | Method of coating low alloy steels |
| JP3255765B2 (en) * | 1993-07-14 | 2002-02-12 | 川崎製鉄株式会社 | Method for producing high-strength hot-dip or alloyed hot-dip galvanized steel sheet |
| US6398884B1 (en) * | 1999-02-25 | 2002-06-04 | Kawasaki Steel Corporation | Methods of producing steel plate, hot-dip steel plate and alloyed hot-dip steel plate |
| BE1014997A3 (en) * | 2001-03-28 | 2004-08-03 | Ct Rech Metallurgiques Asbl | Continuous annealing of steel strip prior to galvanising using direct flame preheating to form an oxide film followed by full annealing and reduction stages to mature this oxide film |
| JP4168667B2 (en) | 2002-05-30 | 2008-10-22 | Ｊｆｅスチール株式会社 | In-line annealing furnace for continuous hot dip galvanizing |
| JP2004280925A (en) | 2003-03-14 | 2004-10-07 | Shinano Kenshi Co Ltd | Optical disk device |
| JP4415579B2 (en) | 2003-06-30 | 2010-02-17 | Ｊｆｅスチール株式会社 | Method for producing hot-dip galvanized steel sheet |
| JP4321181B2 (en) | 2003-08-25 | 2009-08-26 | Ｊｆｅスチール株式会社 | Method for forming an overcoat insulating film containing no chromium |
| JP4140962B2 (en) | 2003-10-02 | 2008-08-27 | 日新製鋼株式会社 | Manufacturing method of low yield ratio type high strength galvannealed steel sheet |
| JP4254823B2 (en) * | 2006-08-30 | 2009-04-15 | カシオ計算機株式会社 | Reaction apparatus and electronic equipment |
| WO2008136870A2 (en) * | 2006-12-18 | 2008-11-13 | University Of Pittsburgh - Of The Commonwealth System Of Higher Education | Fiber optic gas sensor |
-
2006
- 2006-03-29 BE BE2006/0201A patent/BE1017086A3/en not_active IP Right Cessation
-
2007
- 2007-03-13 CN CN2007800112062A patent/CN101466860B/en not_active Expired - Fee Related
- 2007-03-13 ES ES07719191T patent/ES2331634T3/en active Active
- 2007-03-13 AU AU2007231473A patent/AU2007231473B2/en not_active Ceased
- 2007-03-13 MX MX2008012494A patent/MX2008012494A/en active IP Right Grant
- 2007-03-13 DE DE602007002064T patent/DE602007002064D1/en active Active
- 2007-03-13 PL PL07719191T patent/PL1999287T3/en unknown
- 2007-03-13 AT AT07719191T patent/ATE440156T1/en active
- 2007-03-13 JP JP2009501786A patent/JP5140660B2/en not_active Expired - Fee Related
- 2007-03-13 CA CA2644459A patent/CA2644459C/en not_active Expired - Fee Related
- 2007-03-13 KR KR1020087026118A patent/KR101406789B1/en not_active IP Right Cessation
- 2007-03-13 RU RU2008142434/02A patent/RU2426815C2/en not_active IP Right Cessation
- 2007-03-13 WO PCT/BE2007/000026 patent/WO2007109865A1/en active Application Filing
- 2007-03-13 EP EP07719191A patent/EP1999287B1/en not_active Not-in-force
- 2007-03-13 BR BRPI0709419-1A patent/BRPI0709419A2/en not_active Application Discontinuation
- 2007-03-13 UA UAA200812701A patent/UA92079C2/en unknown
- 2007-03-13 US US12/295,084 patent/US8409667B2/en not_active Expired - Fee Related
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Non-Patent Citations (1)
| Title |
|---|
| See references of WO2007109865A1 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10400315B2 (en) | 2013-07-04 | 2019-09-03 | ArcelorMittal Investigación y Desarrollo, S.L. | Cold rolled steel sheet and vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| EP1999287B1 (en) | 2009-08-19 |
| UA92079C2 (en) | 2010-09-27 |
| RU2426815C2 (en) | 2011-08-20 |
| BRPI0709419A2 (en) | 2011-07-12 |
| ATE440156T1 (en) | 2009-09-15 |
| BE1017086A3 (en) | 2008-02-05 |
| US8409667B2 (en) | 2013-04-02 |
| CA2644459A1 (en) | 2007-10-04 |
| KR101406789B1 (en) | 2014-06-12 |
| AU2007231473A1 (en) | 2007-10-04 |
| ES2331634T3 (en) | 2010-01-11 |
| US20100062163A1 (en) | 2010-03-11 |
| KR20080111507A (en) | 2008-12-23 |
| CA2644459C (en) | 2013-11-12 |
| PL1999287T3 (en) | 2010-01-29 |
| AU2007231473B2 (en) | 2010-12-02 |
| WO2007109865A1 (en) | 2007-10-04 |
| MX2008012494A (en) | 2008-12-12 |
| ZA200808424B (en) | 2009-12-30 |
| RU2008142434A (en) | 2010-05-10 |
| JP2009531538A (en) | 2009-09-03 |
| CN101466860B (en) | 2013-05-22 |
| CN101466860A (en) | 2009-06-24 |
| JP5140660B2 (en) | 2013-02-06 |
| DE602007002064D1 (en) | 2009-10-01 |
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