EP3019637B1 - Sheet made of aluminum alloy for the structure of a motor vehicle body - Google Patents

Sheet made of aluminum alloy for the structure of a motor vehicle body Download PDF

Info

Publication number
EP3019637B1
EP3019637B1 EP14758586.3A EP14758586A EP3019637B1 EP 3019637 B1 EP3019637 B1 EP 3019637B1 EP 14758586 A EP14758586 A EP 14758586A EP 3019637 B1 EP3019637 B1 EP 3019637B1
Authority
EP
European Patent Office
Prior art keywords
sheet
use according
hours
temperature
equal
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.)
Active
Application number
EP14758586.3A
Other languages
German (de)
French (fr)
Other versions
EP3019637A1 (en
Inventor
Gilles Guiglionda
Hervé Ribes
Dominique Daniel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Constellium Neuf Brisach SAS
Original Assignee
Constellium Neuf Brisach SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Constellium Neuf Brisach SAS filed Critical Constellium Neuf Brisach SAS
Priority to EP17162984.3A priority Critical patent/EP3199655A3/en
Priority to DE14758586.3T priority patent/DE14758586T1/en
Publication of EP3019637A1 publication Critical patent/EP3019637A1/en
Application granted granted Critical
Publication of EP3019637B1 publication Critical patent/EP3019637B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/047—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with magnesium as the next major constituent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
    • B22D11/003—Aluminium alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/041—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds for vertical casting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D21/00—Casting non-ferrous metals or metallic compounds so far as their metallurgical properties are of importance for the casting procedure; Selection of compositions therefor
    • B22D21/002—Castings of light metals
    • B22D21/007—Castings of light metals with low melting point, e.g. Al 659 degrees C, Mg 650 degrees C
    • 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
    • C21D1/26—Methods of annealing
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/02—Alloys based on aluminium with silicon as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/06—Alloys based on aluminium with magnesium as the next major constituent
    • C22C21/08—Alloys based on aluminium with magnesium as the next major constituent with silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/043—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with silicon as the next major constituent

Definitions

  • the invention relates to the field of aluminum alloy sheets for the manufacture of bodywork parts or automotive structure also called "white box". More specifically, the invention relates to the use of such sheets having excellent formability in stamping, thus making it possible to produce pieces of complex geometry or requiring deep stampings such as for example a door liner or a load floor.
  • the sheets used according to the invention are particularly suitable for the production of complex parts dimensioned in rigidity. They also have excellent resistance to filiform corrosion.
  • Aluminum alloys are increasingly used in the automotive industry to reduce the weight of vehicles and thus reduce fuel consumption and greenhouse gas emissions.
  • the aluminum alloy sheets are used in particular for the manufacture of many parts of the "white box” among which are distinguished body skin parts (or outer body panels) such as the front wings, roofs or pavilions, skins hood, trunk or door, and lining parts or body structure components such as door linings, hood, or load floors (cockpit and trunk). If many pieces of skin are already made of aluminum alloy sheets, the transposition of steel to aluminum lining parts or structure with complex geometries is more difficult because of the poorer formability in stamping of aluminum alloys compared to that of steels.
  • alloys of the Al-Mg-Si type have been retained so far. , that is alloys of the AA6xxx series. Indeed, alloys AA6016, AA6016A, AA6005A, AA6014, for Europe, and alloys AA6111 and AA6022 in the United States, are the most used for this type of applications, in thicknesses of the order of 1mm, mainly because of their relatively good formability in stamping and crimping in the "hardened” T4, their high hardening during the baking of paints and their excellent surface appearance after shaping.
  • alloys of the AA5xxx (Al-Mg) series with a limited magnesium content are, to date, the most used, mainly because they offer a good compromise between formability in the annealed state or state O, mechanical properties after shaping, thermal stability and resistance to corrosion in service.
  • the most commonly used alloys are AA5182, AA5754, and AA5454.
  • JPH036348 discloses an aluminum alloy sheet used for stamped part of bodywork or bodywork structure also called "white box", composition (% by weight): 0.4-1.5% Mg, 0.3-1.5% Si, 0.05- 1.0% Cu, 0.03-1.0% Mn, 0.02-0.5% Ag or / and 0.05-1.0% Fe or / and 0.03-0.3% Cr or / and 0.005-0.1% Ti or / and 0.05-0.2% Zr, remainder aluminum , and the method of manufacturing this part comprises: casting, homogenization at 480-600 ° C, hot rolling, cold rolling, reheating, rapid annealing, work hardening, chemical etching, stamping.
  • the tensile elongation drops to around 25% as soon as the elastic limit Rp 0.2 exceeds the value of substantially 50 MPa.
  • the elongation A 50 rupture of the AA3003 type alloy which is nevertheless known for its good ductility associated with a yield strength R p0.2 of 40 MPa, has its elongation at 50 drop to substantially 25% when magnesium is added to increase the yield strength R p0.2 up to 70 MPa, as appears for alloy AA3004.
  • the aim of the invention is to obtain this compromise of ductility and of optimum yield strength, by proposing an aluminum alloy sheet for automotive structure components, also known as a "white box", having a significantly improved formability that is stable over time. and better than the state of the art, and allowing the realization by conventional embossing at room temperature of automotive parts of complex geometry unrealizable from the aluminum alloy sheets currently used in the field of automotive construction.
  • This sheet must also have a minimum of mechanical strength, but also a very good resistance to corrosion and especially filiform corrosion.
  • the subject of the invention is the use of an aluminum alloy sheet for the manufacture of a stamped part of a bodywork or bodywork structure, also called a "blank body", characterized in that said sheet has a limit of elasticity Rp 0.2 greater than or equal to 60 MPa and an axial tensile elongation A 80 greater than or equal to 34%.
  • said sheet has a hole expansion ratio, known to those skilled in the art under the name HER (Hole Expansion Ratio), greater than 50, or even greater than or equal to 55.
  • its composition is as follows (% by weight): Si: 0.15 - 0.50; Fe: 0.3 - 0.7; Cu: 0.05 - 0.10; Mn: 1.0 - 1.5 or even 1.0 - 1.2 and better 1.1 - 1.2; other elements ⁇ 0.05 each and ⁇ 0.15 in total, remains aluminum.
  • the Fe content is at least 0.3%.
  • the preferred Si content is from 0.15 to 0.30%.
  • the method of manufacturing said sheet comprises the following steps: Vertical continuous or semi-continuous casting of a plate and scalping said plate, Homogenization at a temperature of at least 600 ° C for at least 5 hours, preferably at least 6 hours, followed by controlled cooling to a temperature of 550 to 450 ° C, typically 490 ° C, at least 7 hours, preferably at least 9 hours, then cooling to room temperature in at least 24 hours with, advantageously, controlled slow cooling to substantially 150 ° C in at least 15 hours, preferably at least 15 hours. 16 hours.
  • the chemical etching is carried out, after alkaline degreasing, in an acid medium with a loss of mass of the sheet of at least 0.2 g / m 2 and per face.
  • the invention also encompasses a stamped part of bodywork or body structure manufactured by stamping from a sheet having at least one of the above characteristics. It is chosen, for example, in the group comprising interior panels or door liners, cabin floor, boot floor, spare wheel housing or cockpit side.
  • the invention is based on the finding made by the applicant that it was entirely possible to use, for stamped body panels or bodywork structure also called “white box", sheets having excellent ductility, especially due to an elongation at break of 80 greater than or equal to typically 34%, and a sufficient mechanical strength, in particular because of a yield strength Rp 0.2 greater than or equal to typically 60 MPa, as well as very good resistance to filiform corrosion.
  • Such use has never been used in the automobile because the skilled person wrongly thought that the level of mechanical characteristics was insufficient.
  • this combination is perfectly suitable for parts dimensioned in rigidity, which is the case for most of the stamped bodywork sheets or bodywork structure also called “white box”.
  • Such use has the advantage of excellent formability, especially in stamping, allowing the realization of automotive parts of complex geometry not feasible with aluminum alloys commonly used in the automotive industry. It also allows the conversion of aluminum steel with very little modification of the shape of the tools designed for forming steels other than those related to taking into account the greater thickness of the sheet metal. aluminum alloy used.
  • Fe a minimum content of 0.3%, and better still 0.5%, substantially reduces the solubility of manganese in solid solution, which makes it possible to obtain a sensitivity to the rate of positive deformation, delays the rupture during the deformation after necking, and thus improves ductility and formability.
  • Iron is also necessary for the formation of a high density of intermetallic particles guaranteeing good "hardenability" during shaping. Beyond a content of 0.7%, too many intermetallic particles are created with a detrimental effect on the ductility and resistance to filiform corrosion.
  • Cu at a minimum content of 0.05%, its presence in solid solution makes it possible to obtain higher mechanical characteristics without significant degradation of the formability. Above 0.1%, the sensitivity to the strain rate and thus the formability are substantially degraded. In addition, copper has a negative influence on the corrosion resistance.
  • Mn a minimum content of 1.0% is necessary to obtain the required level of mechanical characteristics and to form sufficient precipitates providing a good "hardenability". Above 1.5%, too much is present in solid solution, which is not conducive to formability.
  • the range of the most advantageous content is 1.0 to 1.2 or even 1.1 to 1.2%.
  • Mg its content is limited to that of an impurity (less than 0.05%).
  • An addition of magnesium could increase the mechanical characteristics by solid solution but would very strongly decrease the sensitivity to the speed of deformation and thus the ductility.
  • Zn in the same way, its content is limited to that of an impurity (less than 0.05% or even 0.01%) because, like magnesium, remaining in solid solution, it would also decrease the sensitivity to the speed of deformation and thus the formability.
  • impurity less than 0.05% or even 0.01%
  • the manufacture of the sheets for use according to the invention mainly comprises the casting, typically vertical semi-continuous plates followed by their scalping.
  • the strip or sheet for use according to the invention is then subjected to work hardening with a permanent deformation rate of between 1 and 10%, and preferably between 1 and 5%.
  • This work-hardening can be obtained for example by rolling with a low reduction of the "skin pass" type, or by planing under tension in tension, or between rollers.
  • This work hardening has the effect of significantly increasing the mechanical strength, including the elastic limit, without significant impact on the elongation at break or ductility.
  • a chemical etching is implemented. It aims to eliminate the mechanically disturbed area resulting from rolling, on the surface of the sheet, known as the MDL (Mechanically Disturbed Layer) or layer of Beilby.
  • the thickness of this disturbed layer depends on the rolling conditions and the reduction in thickness experienced by the sheet; the stripping must therefore be adapted according to these parameters. It is preferably chosen, in this case, so that the loss of mass of the sheet in question is at least 0.2 g / m 2 and per side, better still 0.3 g / m 2 even 0.4 g / m 2 .
  • the examples below show very good results obtained for a value of 0.5 g / m 2 which can therefore be an optimal minimum.
  • the sheet or strip is subjected to a series of treatments comprising at least one etching step and a series of rinses. The purpose of the latter is to remove the chemical residues left at the outlet of the pickling bath or baths.
  • Table 1 summarizes the chemical compositions in percentages by weight (% by weight) of the alloys used during the tests. They are identified by A, A1, A2, B under the abbreviated name "Compo. In Table 2.
  • the next hot rolling step is first carried out on a reversible rolling mill up to a thickness of about 40 mm and then on a hot tandem rolling mill with 4 stands up to a thickness of 3.2 mm.
  • This hot-rolling step is preceded for the case 1 to 6 of a reheating which makes it possible to bring the temperature of the foundry plate from the ambient temperature to the rolling start temperature of 500 ° C. in 9 hours. .
  • This hot rolling step is followed by a cold rolling step which makes it possible to obtain sheets 1.15 mm thick.
  • a final annealing then allows a recrystallization of the alloys so as to obtain a state O.
  • This annealing was carried out in passage furnace for the cases 1 to 4 and 6 to 8 and consisted bringing the metal to a temperature of 410 ° C in about 10 seconds and then cooling it.
  • the recrystallization annealing was carried out in a static oven and consisted in bringing the metal to a temperature of 350 ° C. in 6 hours.
  • a chemical etching of the mechanically disturbed layer resulting from the rolling was also carried out in a reel on a continuous line.
  • the sheet has undergone a series of surface treatments including, after an alkaline degreasing and rinsing, a stripping step with sulfuric and hydrofluoric acids.
  • the attack rate measured by loss of mass on a sample immersed in the pickling bath, was 1.2 g / m 2 per face in 1 minute.
  • the pickling was carried out by spraying on the strip followed by triple rinsing.
  • the loss of mass at the end of the treatment was 0.5 g / m 2 per face for cases 2 to 5.
  • the stripping was less extensive and the mass loss was 0.10 g / m2.
  • Case 7 corresponding to a sheet having not undergone a homogenization of the type of that described in this invention, has a value of elongation at rupture at 80 lower and lower than 34% although the value of Rp 0.2 only 55 MPa.
  • Case 8 corresponding to a sheet of composition outside the invention, has a much smaller elongation A 80 .
  • hole expansion tests were carried out on a sheet according to the invention in comparison with sheet alloys AA5182 type O and AA6016 state T4.
  • the test consists in stamping with a flat-bottomed punch of diameter 202 mm (see figure 1 ) a blank having in its center a circular hole of diameter 100 mm. Stamping is done on blanked side. Blocking of the blank between the die and the blank holder is ensured by means of a retaining ring and a pressure of 13 MPa exerted by the blank clamp.
  • the circular hole of 100 mm diameter is made in the center of a circular blank of 350 mm diameter by water jet cutting.
  • the speed of movement of the punch is 40 mm / min.
  • the movement of the punch stops when the force on the punch falls by 100 daN / 0.2 s, which corresponds to the beginning of a crack from the edge of the hole.
  • the test is finished.
  • the LDH parameter is widely used for the evaluation of the drawability of sheets with a thickness of 0.5 to 2 mm. He has been the subject of many publications, including that of R. Thompson, "The LDH test to evaluate sheet metal formability - Final Report of the LDH Committee of the North American Deep Drawing Research Group," SAE conference, Detroit, 1993, SAE Paper No. 930815. This is a trial of stamping a blank blocked at the periphery by a ring. The blanking pressure is controlled to prevent slippage in the rod. The blank, dimensions 120 x 160 mm, is biased in a mode close to the plane strain. The punch used is hemispherical. The figure 2 specifies the dimensions of the tools used to perform this test.
  • the lubrication between the punch and the plate is ensured by graphited grease (Shell HDM2 grease).
  • the speed of descent of the punch is 50 mm / min.
  • the value called LDH is the value of the displacement of the punch at break, the limit depth of the stamping. It actually corresponds to the average of three tests, giving a 95% confidence interval on the 0.2 mm measurement.
  • Table 2 shows the LDH parameter values obtained on test pieces of 120 x 160 mm cut from the aforementioned sheets and for which the dimension of 160 mm was positioned parallel to the rolling direction.
  • the filiform corrosion resistance was evaluated and compared to that of AA6016-T4 alloy sheets usually used in the field of automobile bodywork.
  • specimens coated with a cataphoresis layer are used. These painted specimens are then scratched, placed in a corrosive atmosphere to initiate corrosion, then exposed to controlled conditions of temperature and humidity favoring filiform corrosion according to standard NF EN 3665. After an exposure time of 1000 hours in climatic chamber at 40 ⁇ 2 ° C and 82 ⁇ 3% humidity, the degree of filiform corrosion is assessed according to standard NF EN 3665 method 3.
  • the degreasing is carried out by immersing for 10 minutes in a "Almeco” bath with a concentration of 18 to 40 g / l and 65 ° C.
  • "metal" is about 0.3 g / m 2 or about 110 nm.
  • the phosphating treatment is carried out by immersion according to the Chemetall instruction manual "Die Phosphatierung als Vor anger vor der Lacktechnik”("Phosphating as pretreatment for painting"). During this step the etching of the metal is about 0.9 g / m 2 or about 330 nm.
  • the phosphate-free conversion treatment by hydrolysis and condensation of polysiloxanes, or Oxsilan®, is carried out by dipping in a bath of Oxsilan® MM0705A at 25 g / l with a withdrawal rate of 25 cm / min, which corresponds to a deposit of about 4 mg Si / m 2 . During this step the metal is not attacked.
  • the cataphoresis product used is CathoGuard® 800 from BASF, an epoxy-based lacquer.
  • the thickness of the targeted cataphoresis layer is 23 microns; it is obtained by a deposit of 2 minutes in a bath at 30 ° C with a voltage of 260 V, followed by baking for 15 minutes at 175 ° C.
  • case 8 all the cases tested, with the exception of case 8, have good resistance to filiform corrosion if the cataphoresis is preceded by a degreasing and phosphating (surface treatment 2).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Metal Rolling (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
  • Body Structure For Vehicles (AREA)
  • ing And Chemical Polishing (AREA)
  • Automobile Manufacture Line, Endless Track Vehicle, Trailer (AREA)
  • Manufacturing & Machinery (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)

Description

Domaine de l'inventionField of the invention

L'invention concerne le domaine des tôles en alliage d'aluminium destinées à la fabrication de pièces de carrosserie ou de structure automobile encore appelée « caisse en blanc ».
Plus précisément, l'invention porte sur l'utilisation de telles tôles possédant une excellente formabilité en emboutissage, permettant ainsi de réaliser des pièces de géométrie complexe ou nécessitant des emboutis profonds comme par exemple une doublure de porte ou un plancher de charge. Les tôles utilisées selon l'invention sont particulièrement adaptées à la réalisation de pièces complexes dimensionnées en rigidité.
Elles présentent par ailleurs une excellente résistance à la corrosion filiforme.The invention relates to the field of aluminum alloy sheets for the manufacture of bodywork parts or automotive structure also called "white box".
More specifically, the invention relates to the use of such sheets having excellent formability in stamping, thus making it possible to produce pieces of complex geometry or requiring deep stampings such as for example a door liner or a load floor. The sheets used according to the invention are particularly suitable for the production of complex parts dimensioned in rigidity.
They also have excellent resistance to filiform corrosion.

Etat de la techniqueState of the art

En préambule, tous les alliages d'aluminium dont il est question dans ce qui suit sont désignés, sauf indication contraire, selon les désignations définies par l'« Aluminum Association » dans les « Registration Record Series » qu'elle publie régulièrement.
Toutes les indications concernant la composition chimique des alliages sont exprimées comme un pourcentage en poids basé sur le poids total de l'alliage.
Les définitions des états métallurgiques sont indiquées dans la norme européenne EN 515.
Les caractéristiques mécaniques statiques en traction, en d'autres termes la résistance à la rupture Rm, la limite d'élasticité conventionnelle à 0,2 % d'allongement Rp0,2, et l'allongement à la rupture A%, sont déterminées par un essai de traction selon la norme NF EN ISO 6892-1.In the preamble, all the aluminum alloys referred to below are designated, unless otherwise indicated, in the terms defined by the "Aluminum Association" in the "Registration Record Series" which it publishes regularly.
All indications regarding the chemical composition of the alloys are expressed as a percentage by weight based on the total weight of the alloy.
The definitions of the metallurgical states are given in the European standard EN 515.
The static mechanical characteristics in tension, in other words the tensile strength R m , the conventional yield stress at 0.2% elongation Rp 0.2, and the elongation at break A% are determined by a tensile test according to standard NF EN ISO 6892-1.

Les alliages d'aluminium sont utilisés de manière croissante dans la construction automobile pour réduire le poids des véhicules et ainsi diminuer la consommation de carburant et les rejets de gaz à effets de serre.
Les tôles en alliage d'aluminium sont utilisées notamment pour la fabrication de nombreuses pièces de la « caisse en blanc » parmi lesquelles on distingue les pièces de peau de carrosserie (ou panneaux extérieurs de carrosserie) comme les ailes avant, toits ou pavillons, peaux de capot, de coffre ou de porte, et les pièces de doublure ou composants de structure de caisse comme par exemple les doublures de porte, de capot, ou les planchers de charge (habitacle et coffre).
Si de nombreuses pièces de peau sont déjà réalisées en tôles d'alliages d'aluminium, la transposition de l'acier à l'aluminium de pièces de doublure ou de structure présentant des géométries complexes s'avère plus délicate du fait de la moins bonne formabilité en emboutissage des alliages d'aluminium comparée à celle des aciers. Un des facteurs limitant l'aptitude à l'emboutissage profond, notamment dans le cas des tôles en alliage d'aluminium, est le phénomène de fissuration à partir des bords de tôle.
En effet, pour les grandes pièces automobiles de géométrie complexe, en particulier comportant des zones nécessitant des emboutis profonds, il est courant de réaliser des flans de forme munis de découpes plus ou moins circulaires à l'intérieur du flan pour faciliter l'écoulement de la matière depuis l'intérieur du flan vers les coins ou les murs profonds. Lors de l'emboutissage, ces découpes intérieures se voient sollicitées en expansion et peuvent être à l'origine d'une rupture prématurée, pour des niveaux de déformation bien en dessous du niveau donné par la Courbe Limite de Formage (CLF).
Il existe cependant d'ores et déjà des automobiles disposant d'une caisse en blanc constituée majoritairement d'alliages aluminium. Toutefois, dans ces cas là, la conception desdites caisses, et notamment le tracé des pièces en tôles embouties, ont été pensés dès l'origine en prenant en compte la formabilité limitée des alliages d'aluminium.
C'est pourquoi les constructeurs d'automobiles sont fortement demandeurs de tôles en alliages d'aluminium présentent une formabilité en emboutissage nettement améliorée qui faciliterait grandement la transposition à l'aluminium de pièces de géométrie complexe actuellement réalisées en acier. Ces dernières pourraient alors être transposées de l'acier à l'aluminium sans qu'il ne soit nécessaire de reconcevoir complètement le tracé ou le découpage des pièces constitutives.
Les coûts de développement d'une nouvelle conception adaptée à l'aluminium ainsi que ceux associés à la fabrication d'outils d'emboutissage spécifiques pourraient être ainsi fortement réduits.
Tel est le contexte de la présente invention.
Plus précisément, à ce jour, le choix des alliages pour application en peau de carrosserie résulte d'un compromis entre exigences parfois antagonistes telles que : formabilité, résistance mécanique finale après cuisson des peintures, limite d'élasticité lors de la mise en forme, aptitude au sertissage, qualité de surface, aptitude à l'assemblage, résistance à la corrosion, coût, aptitude au recyclage, etc... Face à de telles exigences, ont été retenus à ce jour les alliages du type Al-Mg-Si, c'est-à-dire des alliages de la série AA6xxx.
En effet, les alliages des types AA6016, AA6016A, AA6005A, AA6014, pour ce qui est de l'Europe, et les alliages AA6111 et AA6022 aux Etats-Unis, sont les plus utilisés pour ce type d'applications, dans des épaisseurs de l'ordre de 1mm, principalement du fait de leur relativement bonne formabilité en emboutissage et sertissage à l'état « trempé » T4, de leur important durcissement lors de la cuisson des peintures et de leur excellent aspect de surface après mise en forme.
Pour les pièces de doublure ou de structure de caisse, présentant des géométries bien plus complexes, pour lesquelles la formabilité en emboutissage est prépondérante, les alliages de la série AA5xxx (Al-Mg) à teneur limitée en magnésium (typiquement Mg ≤ 5 %) sont, à ce jour, les plus utilisés, principalement parce qu'ils offrent un bon compromis entre formabilité à l'état recuit ou état O, propriétés mécaniques après mise en forme, stabilité thermique et résistance à la corrosion en service. Les plus couramment utilisés sont les alliages des types AA5182, AA5754, et AA5454.Aluminum alloys are increasingly used in the automotive industry to reduce the weight of vehicles and thus reduce fuel consumption and greenhouse gas emissions.
The aluminum alloy sheets are used in particular for the manufacture of many parts of the "white box" among which are distinguished body skin parts (or outer body panels) such as the front wings, roofs or pavilions, skins hood, trunk or door, and lining parts or body structure components such as door linings, hood, or load floors (cockpit and trunk).
If many pieces of skin are already made of aluminum alloy sheets, the transposition of steel to aluminum lining parts or structure with complex geometries is more difficult because of the poorer formability in stamping of aluminum alloys compared to that of steels. One of the factors limiting the deep drawing ability, especially in the case of aluminum alloy sheets, is the phenomenon of cracking from the edges of sheet metal.
Indeed, for large automotive parts of complex geometry, in particular with areas requiring deep stamping, it is common practice to form blanks with more or less circular cutouts inside the blank to facilitate the flow of the material from the inside of the blank to the corners or the deep walls. During stamping, these internal cuts are stretched and can cause premature failure, for deformation levels well below the level given by the Curve Limit of Formation (CLF).
However, there are already automobiles with a white box consisting mainly of aluminum alloys. However, in these cases, the design of said boxes, including the layout of the stamped sheet parts, were thought from the outset taking into account the limited formability of aluminum alloys.
This is why automobile manufacturers are in great demand of aluminum alloy sheets have a significantly improved stamping formability that would greatly facilitate the conversion to aluminum of complex geometry pieces currently made of steel. These could then be transposed from steel to aluminum without the need to redesign the layout or cutting of the component parts.
The costs of developing a new design adapted to aluminum as well as those associated with the manufacture of specific stamping tools could be greatly reduced.
This is the context of the present invention.
More specifically, to date, the choice of alloys for application in body skin results from a compromise between sometimes conflicting requirements such as: formability, final mechanical strength after baking paints, yield strength during shaping, crimpability, surface quality, ability to assemble, corrosion resistance, cost, recyclability, etc. In the face of such requirements, alloys of the Al-Mg-Si type have been retained so far. , that is alloys of the AA6xxx series.
Indeed, alloys AA6016, AA6016A, AA6005A, AA6014, for Europe, and alloys AA6111 and AA6022 in the United States, are the most used for this type of applications, in thicknesses of the order of 1mm, mainly because of their relatively good formability in stamping and crimping in the "hardened" T4, their high hardening during the baking of paints and their excellent surface appearance after shaping.
For liner or body structure parts with much more complex geometries, for which the stamping formability is predominant, alloys of the AA5xxx (Al-Mg) series with a limited magnesium content (typically Mg ≤ 5%) are, to date, the most used, mainly because they offer a good compromise between formability in the annealed state or state O, mechanical properties after shaping, thermal stability and resistance to corrosion in service. The most commonly used alloys are AA5182, AA5754, and AA5454.

En outre, pour la réalisation en alliage d'aluminium de pièces de géométrie complexe, comme notamment une doublure de portière, non réalisable par emboutissage conventionnel avec les alliages précités, différentes solutions ont été envisagées et/ou mises en oeuvre par le passé :

  • Contourner la difficulté liée à l'emboutissage en réalisant ce type de pièces par moulage et notamment du type « Sous-Pression ». En témoigne le brevet EP 1 305 179 B1 de Nothelfer GmbH sous priorité de 2000.
  • Pratiquer un emboutissage dit « à tiède » pour bénéficier d'une meilleure aptitude à l'emboutissage. Cela consiste à chauffer le flan en alliage d'aluminium, totalement ou localement à une température dite intermédiaire, soit de 150 à 350°C, pour améliorer son comportement sous la presse dont l'outillage peut également être préchauffé. Le brevet EP 1 601 478 B1 de la demanderesse, sous priorité de 2003, repose sur cette solution.
  • Modifier, via sa composition, l'aptitude à l'emboutissage de l'alliage de la série AA5xxx lui-même ; il a été notamment proposé d'augmenter la teneur en magnésium au-delà de 5%. Mais ceci n'est pas neutre en termes de résistance à la corrosion.
  • Utiliser des tôles composites constituées d'une âme en alliage de la série AA5xxx, à teneur en Mg au-delà de 5% pour une meilleure formabilité, et d'une tôle de placage en alliage résistant mieux à la corrosion. Mais la résistance à la corrosion en bords de tôle, dans les zones poinçonnées ou plus généralement où l'âme est exposée, et notamment dans les assemblages, peut alors s'avérer insuffisante.
  • Enfin procéder à un laminage asymétrique afin de créer une texture cristallographique plus favorable a également été proposé. En témoigne la demande JP 2003-305503 de Mitsubishi Aluminium). Mais l'industrialisation de ce type de laminage asymétrique est délicate, requiert des laminoirs spécifiques, peut avoir un impact défavorable sur l'aspect de surface des tôles obtenues, et peut aussi engendrer des surcoûts importants.
In addition, for the realization of aluminum alloy parts of complex geometry, such as a door liner, not achievable by conventional stamping with the aforementioned alloys, various solutions have been considered and / or implemented in the past:
  • Bypass the difficulty related to stamping by performing this type of parts by molding and especially the type "under-pressure". Witness the patent EP 1 305 179 B1 from Nothelfer GmbH under priority 2000.
  • Practice a so-called "warm" stamping to obtain a better stamping ability. This consists of heating the blank of aluminum alloy, totally or locally at a so-called intermediate temperature, ie from 150 to 350 ° C., to improve its behavior under the press, the tooling of which can also be preheated. The patent EP 1 601 478 B1 of the applicant, under priority of 2003, is based on this solution.
  • Modify, through its composition, the drawing ability of the alloy AA5xxx series itself; it has been proposed in particular to increase the magnesium content beyond 5%. But this is not neutral in terms of corrosion resistance.
  • Use composite sheets consisting of an alloy core of the AA5xxx series, with a Mg content above 5% for better formability, and an alloy veneer sheet that is more resistant to corrosion. But the corrosion resistance at the edges of the sheet, in the punched areas or more generally where the core is exposed, and in particular in the assemblies, may then be insufficient.
  • Finally, asymmetrical rolling to create a more favorable crystallographic texture has also been proposed. Witness the demand JP 2003-305503 of Mitsubishi Aluminum). But the industrialization of this type of asymmetric rolling is delicate, requires specific rolling mills, can have an adverse impact on the surface appearance of the sheets obtained, and can also generate significant additional costs.

JPH036348 divulgue une tôle en alliage d'aluminium utilisée pour pièce emboutie de carrosserie ou structure de caisse automobile encore appelée "caisse en blanc ", de composition (% en poids) : 0.4-1.5% Mg, 0.3-1.5% Si, 0.05-1.0% Cu,0.03-1.0% Mn, 0.02-0.5% Ag ou/et 0.05-1.0% Fe ou/et 0.03-0.3% Cr ou/et 0.005-0.1% Ti ou/et 0.05-0.2% Zr, reste aluminium,et la procédé de fabrication de cette pièce comporte: coulée, homogénéisation à 480-600°C, laminage à chaud, laminage à froid, réchauffage, recuit rapide, écrouissage, décapage chimique, emboutissage. Enfin, pour ce qui concerne les alliages, une bonne aptitude à l'emboutissage est en général la combinaison d'une bonne aptitude à l'écrouissage, ou « écrouissabilité », si possible se maintenant jusqu'à des déformations intermédiaires de l'ordre de 20 %, d'une bonne ductilité et, pour les pièces de géométrie complexe comprenant des zones embouties profondément, d'un bon comportement en « expansion de trou ». Hormis pour les alliages de la série AA1xxx (aluminium faiblement allié ou de pureté commerciale) qui présentent une excellente ductilité mais associée à des niveaux de caractéristiques mécaniques très faibles, c'est-à-dire typiquement un allongement en traction uni-axiale de A50 = 43 % associé à une limite d'élasticité conventionnelle Rp0,2 de l'ordre de 28 MPa pour un alliage du type AA1060 à l'état O (selon « Aluminum and Aluminum Alloys - ASM Specialty Handbook, Edited by J.R.Davis (1993), Chapter: Properties of Wrought Aluminum and Aluminum Alloys »), il est difficile d'obtenir une excellente ductilité.
Les alliages dits non trempants, de la série AA3xxx (Al-Mn) ou AA5xxx (Al-Mg) ou AA8xxx (Al-Fe-Si), permettent d'obtenir des limites d'élasticité conventionnelles Rp0,2 plus élevées que celles des alliages de la série AA1xxx mais au détriment de la ductilité. Par ailleurs, pour la plupart d'entre eux, l'allongement en traction chute aux alentours de 25 % dès que la limite d'élasticité Rp0,2 dépasse la valeur de sensiblement 50 MPa.
Ainsi, l'allongement à rupture A50 de l'alliage du type AA3003, qui est néanmoins connu pour sa bonne ductilité associée à une limite d'élasticité Rp0,2 de 40 MPa, voit son allongement A50 chuter à sensiblement 25 % lorsque du magnésium est ajouté pour accroître la limite d'élasticité Rp0,2 jusqu'à 70 MPa, comme cela apparaît pour l'alliage AA3004.JPH036348 discloses an aluminum alloy sheet used for stamped part of bodywork or bodywork structure also called "white box", composition (% by weight): 0.4-1.5% Mg, 0.3-1.5% Si, 0.05- 1.0% Cu, 0.03-1.0% Mn, 0.02-0.5% Ag or / and 0.05-1.0% Fe or / and 0.03-0.3% Cr or / and 0.005-0.1% Ti or / and 0.05-0.2% Zr, remainder aluminum , and the method of manufacturing this part comprises: casting, homogenization at 480-600 ° C, hot rolling, cold rolling, reheating, rapid annealing, work hardening, chemical etching, stamping. Finally, as far as alloys are concerned, a good drawability is in general the combination of good work hardenability, or "work hardenability", if possible up to intermediate deformations of the order 20%, good ductility and, for parts of complex geometry including deeply embossed areas, good behavior in "hole expansion". Except for alloys AA1xxx series (low alloy aluminum or commercial purity) which have excellent ductility but are associated with very low levels of mechanical characteristics, i.e. typically uniaxial tension elongation of A 50 = 43% associated with a conventional yield strength R p0.2 of the order of 28 MPa for an AA1060 type alloy at the O state (according to " Aluminum and Aluminum Alloys - ASM Specialty Handbook, Edited by JRDavis (1993), Chapter: Properties of Wrought Aluminum and Aluminum Alloys It is difficult to obtain excellent ductility.
So-called non-hardening alloys, of the AA3xxx (Al-Mn) or AA5xxx (Al-Mg) or AA8xxx (Al-Fe-Si) series, make it possible to obtain conventional yield strengths R p0.2 which are higher than those alloys AA1xxx series but at the expense of ductility. Moreover, for most of them, the tensile elongation drops to around 25% as soon as the elastic limit Rp 0.2 exceeds the value of substantially 50 MPa.
Thus, the elongation A 50 rupture of the AA3003 type alloy, which is nevertheless known for its good ductility associated with a yield strength R p0.2 of 40 MPa, has its elongation at 50 drop to substantially 25% when magnesium is added to increase the yield strength R p0.2 up to 70 MPa, as appears for alloy AA3004.

Le tableau ci-dessous présente, en illustration des propos ci-dessus, les caractéristiques mécaniques typiques mesurées en traction uni axiale à température ambiante d'après « Aluminum and Aluminum Alloys - ASM Specialty Handbook » édité par J.R.Davis (1993), Chapitre: « Properties of Wrought Aluminum and Aluminum Alloys » . Alliage Rp0,2 (MPa) Rm (MPa) A50 (%) ≥99.99%Al AA1199-O 10 45 50 ≥99.6%Al AA1060-O 28 69 43 ≥99.0%Al-0.12Cu Axa1100-0 34 90 40 AI-0.8Mg AA5005-O 41 124 25 Al-1.2Mn-0.12Cu AA3003-O 42 110 30-40 0.55Mn-0.55Mg AA3105-O 55 115 24 Al-1.4Mg AA5050-O 55 145 24 Al-1.2Mn-1.0Mg AA3004-O 69 180 20-25 Al-2.5Mg-0.25Cr AA5052-O 90 195 25 Al-4.5Mg-0.35Mn AA5182-O 138 276 25 0.8Si-0.6Mg-0.5Mn-0.35Cu AA6009-T4 131 234 24 The table below shows, in illustration of the above, the typical mechanical characteristics measured in axial tension at room temperature according to "Aluminum and Aluminum Alloys - ASM Specialty Handbook" edited by JRDavis (1993), Chapter: "Properties of Wrought Aluminum and Aluminum Alloys" . Alloy Rp0.2 (MPa) Rm (MPa) A 50 (%) Al ≥99.99% AA1199-O 10 45 50 ≥99.6% Al AA1060-O 28 69 43 ≥99.0% Al 0.12Cu Axa1100-0 34 90 40 AI-0.8 mg AA5005-O 41 124 25 Al-1.2Mn 0.12Cu AA3003-O 42 110 30-40 0.55Mn-0.55Mg AA3105-O 55 115 24 Al-1.4Mg AA5050-O 55 145 24 Al-1.2Mn 1.0mg AA3004-O 69 180 20-25 Al-2.5mg 0.25Cr AA5052-O 90 195 25 Al-4.5mg 0.35Mn AA5182-O 138 276 25 0.8Si-0.6mg-0.5Mn-0.35Cu AA6009-T4 131 234 24

Problème poséProblem

L'invention vise à obtenir ce compromis de ductilité et de limite d'élasticité optimal, en proposant une tôle en alliage d'aluminium pour composants de structure automobile encore appelée « caisse en blanc », possédant une formabilité nettement améliorée, stable dans le temps et meilleure que l'état de la technique, et autorisant la réalisation par emboutissage conventionnel à température ambiante de pièces automobiles de géométrie complexe irréalisables à partir des tôles en alliage d'aluminium actuellement utilisées dans le domaine de la construction automobile. Cette tôle doit en outre posséder un minimum de résistance mécanique, mais aussi une très bonne résistance à la corrosion et notamment à la corrosion filiforme.The aim of the invention is to obtain this compromise of ductility and of optimum yield strength, by proposing an aluminum alloy sheet for automotive structure components, also known as a "white box", having a significantly improved formability that is stable over time. and better than the state of the art, and allowing the realization by conventional embossing at room temperature of automotive parts of complex geometry unrealizable from the aluminum alloy sheets currently used in the field of automotive construction. This sheet must also have a minimum of mechanical strength, but also a very good resistance to corrosion and especially filiform corrosion.

Objet de l'inventionObject of the invention

L'invention a pour objet l'utilisation d'une tôle en alliage d'aluminium pour la fabrication d'une pièce emboutie de carrosserie ou structure de caisse automobile encore appelée « caisse en blanc », caractérisée en ce que ladite tôle présente une limite d'élasticité Rp0,2 supérieure ou égale à 60 MPa et un allongement en traction uni axiale A80 supérieur ou égal à 34 %.
Avantageusement, ladite tôle présente un rapport d'expansion de trou, connu de l'homme de métier sous l'appellation HER (Hole Expansion Ratio), supérieur à 50, voire supérieur ou égal à 55.
Selon un mode de réalisation préférentielle, sa composition est la suivante (% en poids) : Si : 0,15 - 0,50 ; Fe : 0,3 - 0,7 ; Cu : 0,05 - 0,10 ; Mn : 1,0 - 1,5 voire 1,0 - 1,2 et mieux 1,1 - 1,2; autres éléments < 0,05 chacun et < 0,15 au total, reste aluminium.
Selon un mode encore plus préférentiel, la teneur en Fe est au minimum de 0.3 %. Selon un autre mode, la teneur en Si préférée est de 0,15 à 0,30 %.The subject of the invention is the use of an aluminum alloy sheet for the manufacture of a stamped part of a bodywork or bodywork structure, also called a "blank body", characterized in that said sheet has a limit of elasticity Rp 0.2 greater than or equal to 60 MPa and an axial tensile elongation A 80 greater than or equal to 34%.
Advantageously, said sheet has a hole expansion ratio, known to those skilled in the art under the name HER (Hole Expansion Ratio), greater than 50, or even greater than or equal to 55.
According to a preferred embodiment, its composition is as follows (% by weight): Si: 0.15 - 0.50; Fe: 0.3 - 0.7; Cu: 0.05 - 0.10; Mn: 1.0 - 1.5 or even 1.0 - 1.2 and better 1.1 - 1.2; other elements <0.05 each and <0.15 in total, remains aluminum.
In an even more preferred mode, the Fe content is at least 0.3%. In another embodiment, the preferred Si content is from 0.15 to 0.30%.

De préférence, le procédé de fabrication de ladite tôle comporte les étapes suivantes : Coulée continue ou semi-continue verticale d'une plaque et scalpage de ladite plaque,
Homogénéisation à une température d'au moins 600°C pendant au moins 5 heures, de préférence au moins 6 heures, suivie d'un refroidissement contrôlé jusqu'à la température de 550 à 450°C, typiquement 490°C, en au moins 7 heures, de préférence au moins 9 heures, puis d'un refroidissement jusqu'à température ambiante en au moins 24 heures avec, avantageusement, un refroidissement lent contrôlé jusqu'à sensiblement 150°C en au moins 15 heures, de préférence au moins 16 heures.
Réchauffage à une température de 480 à 530°C avec une montée à température d'au moins 8 heures, laminage à chaud, refroidissement puis laminage à froid et recuit à une température d'au moins 350°C,
Ecrouissage, typiquement par planage en traction ou entre rouleaux ou par « skin pass », avec un taux compris entre 1 et 10 %,
Décapage chimique de la couche mécaniquement perturbée connue sous l'appellation de MDL (Mechanically Disturbed Layer) ou encore couche de Beilby.
Selon un mode de mise en oeuvre plus préféré, le taux d'écrouissage précité est compris entre 1 et 5 %.
Selon un mode avantageux, le décapage chimique est réalisé, après dégraissage alcalin, en milieu acide avec une perte de masse de la tôle d'au moins 0,2 g/m2 et par face.
Enfin, l'invention englobe également une pièce emboutie de carrosserie ou structure de caisse automobile fabriquée par emboutissage à partir d'une tôle présentant l'une au moins des caractéristiques précitées. Elle est choisie, par exemple, dans le groupe comprenant les panneaux intérieurs ou doublures de portières, plancher d'habitacle, plancher de coffre, logement de roue de secours ou encore côté d'habitacle.Preferably, the method of manufacturing said sheet comprises the following steps: Vertical continuous or semi-continuous casting of a plate and scalping said plate,
Homogenization at a temperature of at least 600 ° C for at least 5 hours, preferably at least 6 hours, followed by controlled cooling to a temperature of 550 to 450 ° C, typically 490 ° C, at least 7 hours, preferably at least 9 hours, then cooling to room temperature in at least 24 hours with, advantageously, controlled slow cooling to substantially 150 ° C in at least 15 hours, preferably at least 15 hours. 16 hours.
Reheating at a temperature of 480 to 530 ° C with a temperature rise of at least 8 hours, hot rolling, cooling then cold rolling and annealing at a temperature of at least 350 ° C,
Wetting, typically by planing in tension or between rollers or by "skin pass", with a rate comprised between 1 and 10%,
Chemical etching of the mechanically disturbed layer known as MDL (Mechanically Disturbed Layer) or Beilby layer.
According to a more preferred embodiment, the above-mentioned work-hardening rate is between 1 and 5%.
According to an advantageous embodiment, the chemical etching is carried out, after alkaline degreasing, in an acid medium with a loss of mass of the sheet of at least 0.2 g / m 2 and per face.
Finally, the invention also encompasses a stamped part of bodywork or body structure manufactured by stamping from a sheet having at least one of the above characteristics. It is chosen, for example, in the group comprising interior panels or door liners, cabin floor, boot floor, spare wheel housing or cockpit side.

Description des figuresDescription of figures

  • La figure 1 représente une coupe schématique de l'outillage utilisé pour mesurer le rapport d'expansion de trou (HER) avec en A le serre flan, en B le poinçon et en C la matrice.The figure 1 is a schematic cross-section of the tooling used to measure the hole expansion ratio (HER) with the blank clamp in A, the punch in B and the matrix in C.
  • La figure 2 précise les dimensions en mm des outils utilisés pour déterminer la valeur du paramètre connu de l'homme du métier sous le nom de LDH (Limit Dome Height) caractéristique de l'aptitude à l'emboutissage du matériau.The figure 2 specifies the dimensions in mm of the tools used to determine the value of the parameter known to those skilled in the art under the name of LDH (Limit Dome Height) characteristic of the drawability of the material.
  • La figure 3 représente une structure de portière de véhicule automobile avec, au premier plan, le panneau intérieur typiquement réalisable à partir d'une tôle selon l'invention.The figure 3 represents a door structure of a motor vehicle with, in the foreground, the inner panel typically achievable from a sheet according to the invention.
Description de l'inventionDescription of the invention

L'invention repose sur la constatation faite par la demanderesse qu'il était tout à fait possible d'utiliser, pour des tôles embouties de carrosserie ou structure de caisse automobile encore appelée « caisse en blanc », des tôles possédant une excellente ductilité, notamment du fait d'un allongement à rupture A80 supérieur ou égal à typiquement 34 %, et une résistance mécanique suffisante, notamment du fait d'une limite d'élasticité Rp0,2 supérieure ou égale à typiquement 60 MPa, ainsi qu'une très bonne résistance à la corrosion filiforme.
Une telle utilisation n'a jamais été retenue dans l'automobile car l'homme de métier pensait à tort que le niveau de caractéristiques mécaniques était insuffisant. La demanderesse a découvert que, au contraire, cette combinaison convenait parfaitement pour des pièces dimensionnées en rigidité, ce qui est le cas de la plupart des tôles embouties de carrosserie ou structure de caisse automobile encore appelée « caisse en blanc ».
Une telle utilisation présente l'avantage d'une excellente formabilité, notamment en emboutissage, autorisant la réalisation de pièces automobiles de géométrie complexe non réalisables avec les alliages d'aluminium couramment utilisés dans l'industrie automobile. Elle autorise également des transpositions de l'acier à l'aluminium moyennant très peu de modifications de forme des outils conçu pour le formage des aciers si ce n'est celles liées à la prise en compte de l'épaisseur plus importante de la tôle en alliage d'aluminium utilisée.The invention is based on the finding made by the applicant that it was entirely possible to use, for stamped body panels or bodywork structure also called "white box", sheets having excellent ductility, especially due to an elongation at break of 80 greater than or equal to typically 34%, and a sufficient mechanical strength, in particular because of a yield strength Rp 0.2 greater than or equal to typically 60 MPa, as well as very good resistance to filiform corrosion.
Such use has never been used in the automobile because the skilled person wrongly thought that the level of mechanical characteristics was insufficient. The plaintiff has discovered that, on the contrary, this combination is perfectly suitable for parts dimensioned in rigidity, which is the case for most of the stamped bodywork sheets or bodywork structure also called "white box".
Such use has the advantage of excellent formability, especially in stamping, allowing the realization of automotive parts of complex geometry not feasible with aluminum alloys commonly used in the automotive industry. It also allows the conversion of aluminum steel with very little modification of the shape of the tools designed for forming steels other than those related to taking into account the greater thickness of the sheet metal. aluminum alloy used.

Une composition typique d'alliage pour la tôle utilisée selon l'invention est la suivante (% en poids) : Si : 0,15 - 0,50 ; Fe : 0,3 - 0,7 et mieux 0,5 - 0,7 ; Cu : 0,05 - 0,10 ; Mn : 1,0 - 1,5 et mieux 1,0 - 1,2 voire 1,1 - 1,2; autres éléments < 0,05 chacun et < 0,15 au total, reste aluminium.
Les plages de concentration imposées aux éléments constitutifs de ce type d'alliage s'expliquent par les raisons suivantes :

  • Si: la présence de silicium, à une teneur minimum de 0,15 %, accélère considérablement la cinétique de précipitation du manganèse sous forme de particules intermétalliques fines et nombreuses avec un effet très favorable sur la formabilité.
Au-delà d'une teneur de 0,50 %, il s'avère néfaste pour la formabilité et a une influence significative sur le type de phases au fer obtenues. La fourchette de teneur la plus avantageuse est de 0,1 à 0,30%.A typical alloy composition for the sheet used according to the invention is as follows (% by weight): Si: 0.15 - 0.50; Fe: 0.3 - 0.7 and better 0.5 - 0.7; Cu: 0.05 - 0.10; Mn: 1.0 - 1.5 and better 1.0 - 1.2 or even 1.1 - 1.2; other elements <0.05 each and <0.15 in total, remains aluminum.
The concentration ranges imposed on the constituent elements of this type of alloy can be explained by the following reasons:
  • If: the presence of silicon, at a minimum content of 0.15%, considerably accelerates the kinetics of precipitation of manganese in the form of fine and numerous intermetallic particles with a very favorable effect on the formability.
Beyond a content of 0.50%, it is detrimental to the formability and has a significant influence on the type of iron phases obtained. The most advantageous range of content is 0.1 to 0.30%.

Fe : une teneur minimum de 0,3 %, et mieux 0,5 %, diminue sensiblement la solubilité du manganèse en solution solide, ce qui permet d'obtenir une sensibilité à la vitesse de déformation positive, retarde la rupture lors de la déformation après striction, et donc améliore la ductilité et la formabilité. Le fer est également nécessaire à la formation d'une forte densité de particules intermétalliques garantissant une bonne « écrouissabilité » au cours de la mise en forme.
Au-delà d'une teneur de 0,7 %, trop de particules intermétalliques sont créées avec un effet néfaste sur la ductilité et la résistance à la corrosion filiforme.Fe: a minimum content of 0.3%, and better still 0.5%, substantially reduces the solubility of manganese in solid solution, which makes it possible to obtain a sensitivity to the rate of positive deformation, delays the rupture during the deformation after necking, and thus improves ductility and formability. Iron is also necessary for the formation of a high density of intermetallic particles guaranteeing good "hardenability" during shaping.
Beyond a content of 0.7%, too many intermetallic particles are created with a detrimental effect on the ductility and resistance to filiform corrosion.

Cu : à une teneur minimum de 0,05 %, sa présence en solution solide permet d'obtenir des caractéristiques mécaniques plus élevées sans dégradation sensible de la formabilité.
Au-delà de 0,1%, la sensibilité à la vitesse de déformation et donc la formabilité sont sensiblement dégradées. De plus le cuivre a une influence négative sur la résistance à la corrosion.Cu: at a minimum content of 0.05%, its presence in solid solution makes it possible to obtain higher mechanical characteristics without significant degradation of the formability.
Above 0.1%, the sensitivity to the strain rate and thus the formability are substantially degraded. In addition, copper has a negative influence on the corrosion resistance.

Mn : une teneur minimum de 1,0 % est nécessaire pour obtenir le niveau de caractéristiques mécaniques requis et former suffisamment de précipités fournissant une bonne « écrouissabilité ».
Au-delà de 1,5 %, une trop forte quantité est présente en solution solide, ce qui n'est pas favorable à la formabilité.
La fourchette de teneur la plus avantageuse est de 1,0 à 1,2 voire 1,1 à 1,2 %.Mn: a minimum content of 1.0% is necessary to obtain the required level of mechanical characteristics and to form sufficient precipitates providing a good "hardenability".
Above 1.5%, too much is present in solid solution, which is not conducive to formability.
The range of the most advantageous content is 1.0 to 1.2 or even 1.1 to 1.2%.

Mg : sa teneur est limitée à celle d'une impureté (moins de 0,05 %). Une addition de magnésium pourrait accroître les caractéristiques mécaniques par effet de solution solide mais ferait très fortement décroitre la sensibilité à la vitesse de déformation et donc la ductilité.Mg: its content is limited to that of an impurity (less than 0.05%). An addition of magnesium could increase the mechanical characteristics by solid solution but would very strongly decrease the sensitivity to the speed of deformation and thus the ductility.

Zn : de la même façon, sa teneur est limitée à celle d'une impureté (moins de 0,05 % voire 0,01%) car, tout comme le magnésium, en restant en solution solide, il ferait également décroitre la sensibilité à la vitesse de déformation et donc la formabilité. Les limitations sont identiques pour ce qui est du chrome.Zn: in the same way, its content is limited to that of an impurity (less than 0.05% or even 0.01%) because, like magnesium, remaining in solid solution, it would also decrease the sensitivity to the speed of deformation and thus the formability. The limitations are the same for chrome.

La fabrication des tôles pour utilisation selon l'invention comporte principalement la coulée, typiquement semi continue verticale des plaques suivie de leur scalpage.The manufacture of the sheets for use according to the invention mainly comprises the casting, typically vertical semi-continuous plates followed by their scalping.

Les plaques subissent ensuite une homogénéisation à une température d'au moins 600°C pendant au moins 5 heures, de préférence au moins 6 heures, suivie d'un refroidissement contrôlé jusqu'à la température de 550 à 450°C, typiquement 490°C, en au moins 7 heures, de préférence au moins 9 heures, puis d'un refroidissement jusqu'à température ambiante en au moins 24 heures avec, avantageusement, un refroidissement lent contrôlé jusqu'à sensiblement 150°C en au moins 15 heures, de préférence au moins 16 heures. Ce type d'homogénéisation du type à bi palier, à refroidissement contrôlé, permet d' « expulser » le manganèse de la solution solide par précipitation avec pour effet l'obtention d'une bonne formabilité grâce à :

  • Une sensibilité à la vitesse de déformation élevée (du fait de la faible teneur en solutés dans la solution solide),
  • Une bonne « écrouissabilité » liée à la présence des particules intermétalliques à base de fer et manganèse Fe + Mn fines et nombreuses,
  • Une taille finale de grains faible, liée à l'absence de précipitation de manganèse concomitante avec la recristallisation lors du recuit final, le tout conduisant à une excellente ductilité.
The plates are then homogenized at a temperature of at least 600 ° C for at least 5 hours, preferably at least 6 hours, followed by controlled cooling to a temperature of 550 to 450 ° C, typically 490 ° C. C, in at least 7 hours, preferably at least 9 hours, then cooling to room temperature in at least 24 hours with, advantageously, controlled slow cooling to substantially 150 ° C in at least 15 hours preferably at least 16 hours. This type of homogenization of the bi-bearing type, with controlled cooling, makes it possible to "expel" the manganese from the solid solution by precipitation with the effect of obtaining a good formability thanks to:
  • Sensitivity to the high rate of deformation (due to the low solute content in the solid solution),
  • Good "hardenability" related to the presence of fine and numerous Fe and Mn iron and manganese intermetallic particles,
  • A small final grain size, related to the absence of concomitant manganese precipitation with recrystallization during the final annealing, all leading to excellent ductility.

Elles subissent ensuite un réchauffage à une température de 480 à 530°C avec une montée à température en au moins 8 h, puis le laminage à chaud, le refroidissement puis le laminage à froid.
Les tôles ou bobines sont alors soumises à un recuit à une température d'au moins 350°C.They are then reheated to a temperature of 480 to 530 ° C with a rise in temperature in at least 8 hours, followed by hot rolling, cooling and then cold rolling.
The sheets or coils are then annealed at a temperature of at least 350 ° C.

La bande ou tôle pou utilisation selon l'invention est ensuite soumise à un écrouissage avec un taux de déformation permanente compris entre 1 et 10 %, et de préférence entre 1 et 5 %. Cet écrouissage peut être obtenu par exemple par un laminage à faible réduction de type « skin pass », ou par planage sous tension en traction, ou entre rouleaux. Cet écrouissage a pour effet d'accroître sensiblement la résistance mécanique, notamment la limite d'élasticité, sans incidence notable sur l'allongement à rupture ni sur la ductilité.The strip or sheet for use according to the invention is then subjected to work hardening with a permanent deformation rate of between 1 and 10%, and preferably between 1 and 5%. This work-hardening can be obtained for example by rolling with a low reduction of the "skin pass" type, or by planing under tension in tension, or between rollers. This work hardening has the effect of significantly increasing the mechanical strength, including the elastic limit, without significant impact on the elongation at break or ductility.

Enfin, un décapage chimique est mis en oeuvre. Il a pour objectif d'éliminer la zone mécaniquement perturbée issue du laminage, en surface de la tôle, et connue sous l'appellation de MDL (Mechanically Disturbed Layer) ou encore couche de Beilby.
L'épaisseur de cette couche perturbée dépend des conditions de laminage et de la réduction d'épaisseur subies par la tôle ; le décapage doit donc être adapté en fonction de ces paramètres.
Il est choisi de préférence, dans le cas présent, de façon à ce que la perte de masse de la tôle en question soit d'au moins 0,2 g/m2 et par face, mieux encore 0,3 g/m2 voire 0,4 g/m2. Les exemples ci après montrent de très bons résultats obtenus pour une valeur de 0,5 g/m2 qui peut donc constituer un minimum optimal.
Il peut être réalisé soit à partir d'une bobine sur une ligne continue de traitements de surface chimiques, par aspersion ou immersion de la bande déroulée, soit sur des flans de tôle découpés, par immersion dans des bains.
En pratique, la tôle ou bande est soumise à une série de traitements comprenant au minimum une étape de décapage et une série de rinçages. Ces derniers ont pour but d'éliminer les résidus de produits chimiques laissés en sortie du ou des bains de décapage.Finally, a chemical etching is implemented. It aims to eliminate the mechanically disturbed area resulting from rolling, on the surface of the sheet, known as the MDL (Mechanically Disturbed Layer) or layer of Beilby.
The thickness of this disturbed layer depends on the rolling conditions and the reduction in thickness experienced by the sheet; the stripping must therefore be adapted according to these parameters.
It is preferably chosen, in this case, so that the loss of mass of the sheet in question is at least 0.2 g / m 2 and per side, better still 0.3 g / m 2 even 0.4 g / m 2 . The examples below show very good results obtained for a value of 0.5 g / m 2 which can therefore be an optimal minimum.
It can be made either from a coil on a continuous line of chemical surface treatments, by spraying or immersing the unwound strip, or on cut sheet blanks, by immersion in baths.
In practice, the sheet or strip is subjected to a series of treatments comprising at least one etching step and a series of rinses. The purpose of the latter is to remove the chemical residues left at the outlet of the pickling bath or baths.

Dans ses détails, l'invention sera mieux comprise à l'aide des exemples ci-après, qui n'ont toutefois pas de caractère limitatif.In its details, the invention will be better understood with the aid of the following examples, which are however not limiting in nature.

ExemplesExamples PréambulePreamble

Le Tableau 1 récapitule les compositions chimiques en pourcentages massiques (% en poids) des alliages utilisés lors des essais. Elles sont repérées par A, A1, A2, B sous l'appellation abrégée « Compo. » au Tableau 2.Table 1 summarizes the chemical compositions in percentages by weight (% by weight) of the alloys used during the tests. They are identified by A, A1, A2, B under the abbreviated name "Compo. In Table 2.

Des plaques de fonderie de ces différents alliages ont été obtenues par coulée semi-continue verticale.
Après scalpage, ces différentes plaques ont subi un traitement thermique d'homogénéisation (repère « Homo. » au Tableau 2).
Comme indiqué au Tableau 2, les plaques des cas 1 à 6 ont subi un traitement d'homogénéisation à 610°C consistant en une montée en température en 16 heures jusqu'à 600°C, un maintien de 8 heures entre 600 et 610°C puis un refroidissement contrôlé jusqu'à 490°C en 9 heures, puis jusqu'à la température ambiante en un jour environ.
Les plaques des cas 7 et 8 ont subi un traitement d'homogénéisation plus court consistant en une montée à 610°C sans maintien suivie d'un refroidissement à 530°C en 5 heures, directement suivie du laminage à chaud.
Les plaques des exemples comparatifs 9 et 10, constitués d'alliages du type AA6016 et AA5182, ont subi des homogénéisations classiques pour ces types d'alliages.Foundry plates of these different alloys were obtained by vertical semi-continuous casting.
After scalping, these different plates have undergone a homogenization heat treatment (reference "Homo" in Table 2).
As shown in Table 2, the plates of cases 1 to 6 were subjected to a homogenization treatment at 610 ° C consisting of a temperature rise in 16 hours up to 600 ° C, a hold of 8 hours between 600 and 610 ° C then controlled cooling to 490 ° C in 9 hours, and then to room temperature in about a day.
The plates of cases 7 and 8 underwent a shorter homogenization treatment consisting of a rise at 610 ° C without holding followed by cooling at 530 ° C in 5 hours, followed directly by hot rolling.
The plates of Comparative Examples 9 and 10, consisting of AA6016 and AA5182 type alloys, have undergone standard homogenizations for these types of alloys.

L'étape suivante de laminage à chaud a lieu d'abord sur un laminoir réversible jusqu'à une épaisseur de l'ordre de 40 mm puis sur un laminoir tandem à chaud à 4 cages jusqu'à une épaisseur de 3.2 mm. Cette étape de laminage à chaud est précédée pour les cas 1 à 6 d'un réchauffage qui permet d'amener la température de la plaque de fonderie de la température ambiante jusqu'à la température de début de laminage de 500°C en 9 heures.The next hot rolling step is first carried out on a reversible rolling mill up to a thickness of about 40 mm and then on a hot tandem rolling mill with 4 stands up to a thickness of 3.2 mm. This hot-rolling step is preceded for the case 1 to 6 of a reheating which makes it possible to bring the temperature of the foundry plate from the ambient temperature to the rolling start temperature of 500 ° C. in 9 hours. .

Cette étape de laminage à chaud est suivie d'une étape de laminage à froid qui permet d'obtenir des tôles de 1.15 mm d'épaisseur.
Pour les cas 1 à 8 et pour le cas 10, un recuit final permet ensuite une recristallisation des alliages de façon à obtenir un état O. Ce recuit a été effectué en four à passage pour les cas 1 à 4 et 6 à 8 et consistait à amener le métal jusqu'à une température de 410°C en environ 10 secondes puis à le refroidir. Pour le cas 5, le recuit de recristallisation a été effectué en four statique et consistait à amener le métal à une température de 350°C en 6 heures. Pour l'exemple comparatif 10, en alliage du type AA5182, le recuit de recristallisation a eu lieu en four à passage et consistait à amener le métal jusqu'à une température de 365°C en 30 secondes environ puis à le refroidir.
Pour l'exemple comparatif 9, en alliage du type AA6016, le laminage à froid a été également suivi d'un traitement thermique en fin de gamme mais celui-ci est différent et consiste en une mise en solution et trempe réalisées en four à passage par élévation de la température du métal jusqu'à 540°C en 30 secondes environ et trempe.This hot rolling step is followed by a cold rolling step which makes it possible to obtain sheets 1.15 mm thick.
For the cases 1 to 8 and for the case 10, a final annealing then allows a recrystallization of the alloys so as to obtain a state O. This annealing was carried out in passage furnace for the cases 1 to 4 and 6 to 8 and consisted bringing the metal to a temperature of 410 ° C in about 10 seconds and then cooling it. For case 5, the recrystallization annealing was carried out in a static oven and consisted in bringing the metal to a temperature of 350 ° C. in 6 hours. For Comparative Example 10, of AA5182 alloy, the recrystallization annealing took place in a pass-through oven and consisted of bring the metal to a temperature of 365 ° C in about 30 seconds and then cool.
For Comparative Example 9, alloy AA6016 type, the cold rolling was also followed by a heat treatment at the end of the range but it is different and consists of a solution and quenching performed in a passage oven by raising the metal temperature up to 540 ° C in about 30 seconds and quenching.

Pour les cas 2 à 6 un décapage chimique de la couche mécaniquement perturbée issue du laminage a également été effectué en bobine sur une ligne continue. La tôle a subi une série de traitements de surface comprenant, après un dégraissage alcalin et un rinçage, une étape de décapage aux acides sulfurique et fluorhydrique. Le taux d'attaque, mesuré par perte de masse sur un échantillon immergé dans le bain de décapage, était de 1.2 g/m2 par face en 1 minute. Dans cet exemple, le décapage a été réalisé par aspersion sur la bande suivi d'un triple rinçage. La perte de masse à l'issue du traitement était de 0.5 g/m2 par face pour les cas 2 à 5. Pour le cas 6, le décapage a été moins poussé et la perte de masse était de 0.10 g/m2.For cases 2 to 6, a chemical etching of the mechanically disturbed layer resulting from the rolling was also carried out in a reel on a continuous line. The sheet has undergone a series of surface treatments including, after an alkaline degreasing and rinsing, a stripping step with sulfuric and hydrofluoric acids. The attack rate, measured by loss of mass on a sample immersed in the pickling bath, was 1.2 g / m 2 per face in 1 minute. In this example, the pickling was carried out by spraying on the strip followed by triple rinsing. The loss of mass at the end of the treatment was 0.5 g / m 2 per face for cases 2 to 5. For case 6, the stripping was less extensive and the mass loss was 0.10 g / m2.

Enfin, pour les cas 2 à 6, la tôle est passée dans une planeuse sous tension , de manière à légèrement déformer plastiquement le matériau entre 1 et 5 % environ. Tableau 1 Composition Si Fe Cu Mn Mg Cr Zn Ti A 0.22 0.63 0.08 1.14 0.003 0.002 0.003 0.012 A1 0.21 0.59 0.08 1.17 0.002 0.002 0.002 0.013 A2 0.20 0.57 0.08 1.14 0.0046 0.001 0.002 0.012 B 0.22 0.42 0.16 1.02 1.19 0.021 0.002 0.008 6016 1.07 0.21 0.09 0.17 0.40 0.042 0.007 0.017 5182 0.12 0.29 0.06 0.32 4.73 0.030 0.008 0.014 Tableau 2 Cas Compo. Homo. Décapage Planage Rp0,2 (MPa) A80 (%) HER LDH (mm) Corrosion filiforme Comparatif 1 A 610°+Refr. contrôlé non non 49 37.5 68 35.7 Mauvais Invention 2 A 610°+Refr. contrôlé oui oui 70 37.3 63 34.7 Bon Invention 3 A 610°+Refr. contrôlé oui oui 81 35.2 57 34.0 Bon Invention 4 A 610°+Refr. contrôlé oui oui 84 35.6 56 33.0 Bon Invention 5 A1 610°+Refr. contrôlé oui oui 61 37.0 67 34.6 Bon Comparatif 6 A 610°+Refr. contrôlé partiel oui 94 32.8 50 31.3 Mauvais Comparatif 7 A2 610°C non non 55 29.2 45 28.4 Mauvais Comparatif 8 B 610°C non non 67 22.0 40 26.0 Mauvais Comparatif 9 6016-T4 - - - 112 24.0 39 26.2 Mauvais Comparatif 10 5182-O - - - 146 24.2 35 33.9 - Finally, for cases 2 to 6, the sheet is passed through a tensioning machine, so as to slightly plastically deform the material between 1 and 5%. <b> Table 1 </ b> Composition Yes Fe Cu mn mg Cr Zn Ti AT 0.22 0.63 0.08 1.14 0003 0002 0003 0012 A1 0.21 0.59 0.08 1.17 0002 0002 0002 0013 A2 0.20 0.57 0.08 1.14 0.0046 0001 0002 0012 B 0.22 0.42 0.16 1.02 1.19 0021 0002 0008 6016 1.07 0.21 0.09 0.17 0.40 0042 0007 0017 5182 0.12 0.29 0.06 0.32 4.73 0030 0008 0014 Case Compo. Homo. scouring leveling Rp 0.2 (MPa) A 80 (%) HER LDH (mm) Filiform corrosion Comparative 1 AT + 610 ° Refr. control no no 49 37.5 68 35.7 Bad Invention 2 AT + 610 ° Refr. control Yes Yes 70 37.3 63 34.7 Well Invention 3 AT + 610 ° Refr. control Yes Yes 81 35.2 57 34.0 Well Invention 4 AT + 610 ° Refr. control Yes Yes 84 35.6 56 33.0 Well Invention 5 A1 + 610 ° Refr. control Yes Yes 61 37.0 67 34.6 Well Comparative 6 AT + 610 ° Refr. control partial Yes 94 32.8 50 31.3 Bad Comparative 7 A2 610 ° C no no 55 29.2 45 28.4 Bad Comparative 8 B 610 ° C no no 67 22.0 40 26.0 Bad Comparative 9 6016-T4 - - - 112 24.0 39 26.2 Bad Comparative 10 5182-O - - - 146 24.2 35 33.9 -

Pour l'ensemble des cas 1 à 10, la formabilité et la résistance à la corrosion filiforme des tôles obtenues ont été évaluées. Ces différentes caractérisations et les résultats associés sont détaillés ci après.For all cases 1 to 10, the formability and resistance to filiform corrosion of the sheets obtained were evaluated. These different characterizations and the associated results are detailed below.

Essais de tractionTraction tests

Les essais de traction à température ambiante ont été réalisés selon la norme NF EN ISO 6892-1 avec des éprouvettes non proportionnelles, de géométrie largement utilisée pour les tôles, et correspondant au type d'éprouvette 2 du tableau B.1 de l'annexe B de ladite norme.
Ces éprouvettes possèdent notamment une largeur de 20 mm et une longueur calibrée de 120 mm.
L'allongement pour cent (A%) après rupture a été mesuré à l'aide d'un extensomètre de base 80 mm et est donc noté A80 conformément à cette même norme.Tensile tests at ambient temperature were carried out according to standard NF EN ISO 6892-1 with non-proportional specimens, of widely used geometry for the sheets, and corresponding to the type of specimen 2 of Table B.1 of the appendix. B of said standard.
These specimens have in particular a width of 20 mm and a calibrated length of 120 mm.
The percent elongation (A%) after fracture was measured using an 80 mm extensometer and is therefore rated at 80 in accordance with this standard.

Comme mentionné dans la note du paragraphe 20.3 de la norme ISO 6892-1:2009(F) (page 19), il est important de noter que « Des comparaisons d'allongement pour cent sont possibles uniquement lorsque la longueur entre repères ou la longueur de base de l'extensomètre, la forme et l'aire de la section transversale sont les mêmes ou lorsque le coefficient de proportionnalité, k, est le même. »
Notamment, il n'est pas possible de directement comparer des valeurs d'allongements pour cent A50 mesurées avec une base d'extensométrie de 50 mm à des valeurs d'allongement pour cent A80 mesurées avec une base d'extensométrie de 80 mm. Dans le cas particulier d'une éprouvette de même géométrie prise dans une même matière, la valeur d'allongement pour cent A50 sera plus élevée que la valeur d'allongement pour cent A80 et donnée par la relation : A50 = Ag + (A80 - Ag)*80/50 où Ag, en %, est l'extension plastique à la force maximale, aussi appelé « allongement généralisé » ou « allongement à striction ».As mentioned in the note to paragraph 20.3 of ISO 6892-1: 2009 (F) (page 19), it is important to note that "percent lengthwise comparisons are possible only when the gauge length or length of the extensometer, the shape and area of the cross-section are the same or when the proportionality coefficient, k, is the same. "
In particular, it is not possible to directly compare percent elongation values measured at 50 with 50 mm extensometry base at 80 percent elongation values measured with an 80 mm extensometry base. . In the particular case of a specimen of the same geometry taken from the same material, the elongation value per cent A 50 will be higher than the elongation value per cent A 80 and given by the relation: A 50 = Ag + (A 80 - Ag) * 80/50 where Ag, in%, is the plastic extension at maximum force, also called "generalized elongation" or "necking elongation".

Les résultats de ces essais de traction en termes de limite conventionnelle d'élasticité à 0.2%, Rp0,2, et d'allongement pour cent A80, sur une longueur initiale Lo entre repères de 80 mm, sont donnés dans le Tableau 2.
On y relève clairement que les cas 2 à 5, correspondant à des tôles selon l'invention, sont les seuls à combiner des valeurs d'allongement à rupture A80 supérieures ou égales à 34 % combinées à des valeurs de limite d'élasticité conventionnelle Rp0,2 supérieures ou égales à 60 MPa.
Le cas 1, correspondant à une tôle n'ayant pas subi l'étape de planage, présente une valeur de Rp0,2 plus faible égale à 49 MPa.
Le cas 7, correspondant à une tôle n'ayant pas subi une homogénéisation du type de celle décrite dans cette invention, présente une valeur d'allongement à rupture A80 plus faible et inférieure à 34 % bien que la valeur de Rp0,2 soit de 55 MPa seulement. Le cas 8, correspondant à une tôle de composition hors de l'invention, présente un allongement A80 nettement plus réduit.
Les tôles des cas comparatifs (9 et 10), en alliages 6016-T4 et 5182-O habituellement utilisées pour les panneaux de carrosserie automobile, présentent également des valeurs A80 nettement plus basses, autour de 24 %.The results of these tensile tests in terms of the 0.2% yield strength, Rp 0.2 , and the percent elongation A 80 , over an initial length Lo between 80 mm marks, are given in Table 2. .
It is clearly noted that cases 2 to 5, corresponding to plates according to the invention, are the only ones to combine elongation at break values A 80 greater than or equal to 34% combined with conventional yield strength values. Rp 0.2 greater than or equal to 60 MPa.
Case 1, corresponding to a sheet that has not undergone the leveling step, has a lower value of Rp 0.2 equal to 49 MPa.
Case 7, corresponding to a sheet having not undergone a homogenization of the type of that described in this invention, has a value of elongation at rupture at 80 lower and lower than 34% although the value of Rp 0.2 only 55 MPa. Case 8, corresponding to a sheet of composition outside the invention, has a much smaller elongation A 80 .
The plates of the comparative cases (9 and 10), in alloys 6016-T4 and 5182-O usually used for automobile body panels, also have significantly lower A 80 values, around 24%.

Mesure du taux d'expansion de trou HER (Hole Expansion Ratio)HER (Hole Expansion Ratio) Hole Expansion Rate Measurement

Comme dit au chapitre « Etat de la technique », un des facteurs limitant l'aptitude à l'emboutissage profond est le phénomène de fissuration à partir des bords de tôle.As said in the chapter "State of the art", one of the factors limiting the deep drawing ability is the phenomenon of cracking from the edges of sheet metal.

Dans cet exemple, des essais d'expansion de trou ont été réalisés sur une tôle selon l'invention en comparaison avec des tôles en alliages du type AA5182 à l'état O et AA6016 à l'état T4.
L'essai consiste à emboutir avec un poinçon à fond plat de diamètre 202 mm (voir figure 1) un flan possédant en son centre un trou circulaire de diamètre 100 mm. L'emboutissage se fait à flan bloqué. Le blocage du flan entre la matrice et le serre-flan est assuré au moyen d'un jonc de retenu et d'une pression de 13 MPa exercée par le serre flan. Le trou circulaire de 100 mm de diamètre est réalisé au centre d'un flan circulaire de 350 mm de diamètre par découpe au jet d'eau. La vitesse de déplacement du poinçon est de 40 mm/min. Le déplacement du poinçon s'arrête lorsque la force sur le poinçon chute de 100 daN/0.2 s, ce qui correspond à l'amorce d'une fissure depuis le bord du trou. L'essai est alors terminé. On caractérise la performance des matières dans ce test d'expansion de trou par ce qu'on appelle « le rapport d'expansion de trou » HER défini par HER = (Df-Di)/Di où Di est le diamètre initial du trou dans le flan (ici 100 mm) et Df est le diamètre final du trou après l'arrêt du test.In this example, hole expansion tests were carried out on a sheet according to the invention in comparison with sheet alloys AA5182 type O and AA6016 state T4.
The test consists in stamping with a flat-bottomed punch of diameter 202 mm (see figure 1 ) a blank having in its center a circular hole of diameter 100 mm. Stamping is done on blanked side. Blocking of the blank between the die and the blank holder is ensured by means of a retaining ring and a pressure of 13 MPa exerted by the blank clamp. The circular hole of 100 mm diameter is made in the center of a circular blank of 350 mm diameter by water jet cutting. The speed of movement of the punch is 40 mm / min. The movement of the punch stops when the force on the punch falls by 100 daN / 0.2 s, which corresponds to the beginning of a crack from the edge of the hole. The test is finished. The performance of the materials in this hole expansion test is characterized by the so-called "hole expansion ratio" HER defined by HER = (Df-Di) / Di where Di is the initial diameter of the hole in the blank (here 100 mm) and Df is the final diameter of the hole after stopping the test.

Les résultats obtenus lors de ces essais sont rassemblés au Tableau 2 dans la colonne notée HER où sont présentées les valeurs de rapport d'expansion de trou.
On notera que les cas 2 à 5, correspondant à des tôles selon l'invention, sont les seuls à combiner des valeurs de rapport d'expansion de trou HER supérieures à 50, voire 55, avec des valeurs de limite d'élasticité conventionnelle Rp0,2 supérieures ou égales à 60 MPa.
Le cas 1, correspondant à une tôle n'ayant pas subi l'étape de planage, présente une valeur de HER supérieure à 50 mais associée à une faible valeur de Rp0,2 de 49 MPa. Les autres cas comparatifs (7 à 10) présentent des valeurs de HER nettement inférieures à celles des tôles selon l'invention.The results obtained in these tests are collated in Table 2 in the column labeled HER, where the hole expansion ratio values are presented.
It should be noted that cases 2 to 5, corresponding to plates according to the invention, are the only ones to combine HER hole expansion ratio values greater than 50 or even 55 with conventional yield strength values Rp. 0.2 greater than or equal to 60 MPa.
Case 1, corresponding to a sheet that did not undergo the planing step, has a HER value greater than 50 but associated with a low Rp 0.2 value of 49 MPa. The other comparative cases (7 to 10) have HER values significantly lower than those of the plates according to the invention.

Mesure du LDH (Limit Dome Height).Measurement of LDH (Limit Dome Height).

Ces mesures de LDH (Limit Dome Height) ont été réalisées afin de caractériser la performance en emboutissage des différentes tôles de cet exemple.These measurements of LDH (Limit Dome Height) were carried out in order to characterize the stamping performance of the various sheets of this example.

Le paramètre LDH est largement utilisé pour l'évaluation de l'aptitude à l'emboutissage des tôles d'épaisseur de 0,5 à 2 mm. Il a fait l'objet de nombreuses publications, notamment celle de R. Thompson, « The LDH test to evaluate sheet metal formability - Final Report of the LDH Committee of the North American Deep Drawing Research Group », SAE conference, Detroit, 1993, SAE Paper n°930815.
Il s'agit d'un essai d'emboutissage d'un flan bloqué en périphérie par un jonc. La pression de serre-flan est contrôlée pour éviter un glissement dans le jonc. Le flan, de dimensions 120 x 160 mm, est sollicité dans un mode proche de la déformation plane. Le poinçon utilisé est hémisphérique.
La figure 2 précise les dimensions des outils utilisés pour réaliser ce test.
La lubrification entre le poinçon et la tôle est assurée par de la graisse graphitée (graisse Shell HDM2). La vitesse de descente du poinçon est de 50 mm/min. La valeur dite LDH est la valeur du déplacement du poinçon à rupture, soit la profondeur limite de l'emboutissage. Elle correspond en fait à la moyenne de trois essais, donnant un intervalle de confiance à 95 % sur la mesure de 0,2 mm.
Le tableau 2 indique les valeurs du paramètre LDH obtenues sur des éprouvettes de 120 x 160 mm découpées dans les tôles précitées et pour lesquelles la dimension de 160 mm était positionnée parallèlement à la direction de laminage.The LDH parameter is widely used for the evaluation of the drawability of sheets with a thickness of 0.5 to 2 mm. He has been the subject of many publications, including that of R. Thompson, "The LDH test to evaluate sheet metal formability - Final Report of the LDH Committee of the North American Deep Drawing Research Group," SAE conference, Detroit, 1993, SAE Paper No. 930815.
This is a trial of stamping a blank blocked at the periphery by a ring. The blanking pressure is controlled to prevent slippage in the rod. The blank, dimensions 120 x 160 mm, is biased in a mode close to the plane strain. The punch used is hemispherical.
The figure 2 specifies the dimensions of the tools used to perform this test.
The lubrication between the punch and the plate is ensured by graphited grease (Shell HDM2 grease). The speed of descent of the punch is 50 mm / min. The value called LDH is the value of the displacement of the punch at break, the limit depth of the stamping. It actually corresponds to the average of three tests, giving a 95% confidence interval on the 0.2 mm measurement.
Table 2 shows the LDH parameter values obtained on test pieces of 120 x 160 mm cut from the aforementioned sheets and for which the dimension of 160 mm was positioned parallel to the rolling direction.

Ces résultats mettent en évidence le fait que les tôles selon l'invention (cas 2 à 5) possèdent des valeurs de LDH élevées, supérieures ou égales à 32 mm. Ces valeurs sont similaires ou supérieures à la valeur de LDH obtenue pour une tôle en alliage 5182-O (cas 10), alliage de référence lorsqu'il s'agit de panneaux de carrosserie pour emboutissages sévères.
L'exemple comparatif (cas 1), présente également une valeur de LDH supérieure à 32 mm, mais associée à une valeur de Rp0,2 assez faible égale à 49 MPa. Inversement le cas 6 présente une valeur de Rp0,2 élevée, égale à 94 MPa, mais associée à une valeur de LDH inférieure à 32 mm.
Les exemples comparatifs 7 à 9, correspondant à des tôles n'ayant pas subi le traitement d'homogénéisation ou bien dont la composition chimique est hors invention, présentent des valeurs de LDH nettement inférieures à celles des tôles selon l'invention.These results highlight the fact that the sheets according to the invention (cases 2 to 5) have high LDH values greater than or equal to 32 mm. These values are similar to or greater than the LDH value obtained for an alloy sheet 5182-O (case 10), a reference alloy for body panels for severe stampings.
The comparative example (case 1) also has an LDH value of greater than 32 mm, but associated with a rather low Rp 0.2 value equal to 49 MPa. Conversely Case 6 has a high value of Rp 0.2 , equal to 94 MPa, but associated with an LDH value of less than 32 mm.
Comparative Examples 7 to 9, corresponding to sheets that have not undergone the homogenization treatment or whose chemical composition is outside the invention, have LDH values that are significantly lower than those of the sheets according to the invention.

Evaluation de la résistance à la corrosion filiformeEvaluation of filiform corrosion resistance

La résistance à la corrosion filiforme a été évaluée et comparée à celle de tôles en alliage du type AA6016-T4 habituellement utilisé dans le domaine de la carrosserie automobile.
Pour cela, on utilise des éprouvettes revêtues d'une couche de cataphorèse. Ces éprouvettes peintes sont alors rayées, placées dans une atmosphère corrosive pour initier la corrosion, puis exposées à des conditions contrôlées de température et d'humidité favorisant la corrosion filiforme selon la norme NF EN 3665. Après une durée d'exposition de 1000 heures en enceinte climatique à 40 ± 2°C et 82 ± 3 % d'humidité, le degré de corrosion filiforme est apprécié selon la norme NF EN 3665 méthode 3.The filiform corrosion resistance was evaluated and compared to that of AA6016-T4 alloy sheets usually used in the field of automobile bodywork.
For this purpose, specimens coated with a cataphoresis layer are used. These painted specimens are then scratched, placed in a corrosive atmosphere to initiate corrosion, then exposed to controlled conditions of temperature and humidity favoring filiform corrosion according to standard NF EN 3665. After an exposure time of 1000 hours in climatic chamber at 40 ± 2 ° C and 82 ± 3% humidity, the degree of filiform corrosion is assessed according to standard NF EN 3665 method 3.

Trois types de traitements de surface ont été réalisés avant cataphorèse :

  • Traitement de surface 1 : dégraissage
  • Traitement de surface 2 : dégraissage + phosphatation
  • Traitement de surface 3 : dégraissage + conversion « Oxsilan® »
Three types of surface treatments were performed before cataphoresis:
  • Surface treatment 1: degreasing
  • Surface treatment 2: degreasing + phosphating
  • Surface treatment 3: degreasing + "Oxsilan®" conversion

Le dégraissage est réalisé par immersion pendant 10 minutes dans un bain « Almeco » d'une concentration de 18 à 40 g/1 et à 65°C. Au cours de ce dégraissage l'attaque du « métal » est d'environ 0.3 g/m2 soit environ 110 nm.The degreasing is carried out by immersing for 10 minutes in a "Almeco" bath with a concentration of 18 to 40 g / l and 65 ° C. During the degreasing attack "metal" is about 0.3 g / m 2 or about 110 nm.

Le traitement de phosphatation est réalisé par immersion selon le manuel d'instruction de Chemetall « Die Phosphatierung als Vorbehandlung vor der Lackierung » (« La phosphatation comme prétraitement pour la peinture »). Au cours de cette étape l'attaque du métal est d'environ 0.9 g/m2 soit environ 330 nm.The phosphating treatment is carried out by immersion according to the Chemetall instruction manual "Die Phosphatierung als Vorbehandlung vor der Lackierung"("Phosphating as pretreatment for painting"). During this step the etching of the metal is about 0.9 g / m 2 or about 330 nm.

Le traitement de conversion sans phosphate, par hydrolyse et condensation de polysiloxanes, ou Oxsilan®, est effectué au trempé dans un bain d'Oxsilan® MM0705A à 25 g/1 avec une vitesse de retrait de 25 cm/min, ce qui correspond à un dépôt d'environ 4 mg Si / m2. Au cours de cette étape le métal n'est pas attaqué.
Le produit de cataphorèse utilisé est le CathoGuard® 800 de chez BASF, laque à base époxy. L'épaisseur de la couche de cataphorèse visée est de 23 microns ; elle est obtenue par un dépôt de 2 minutes dans un bain à 30°C avec une tension de 260 V, suivi d'une cuisson de 15 minutes à 175°C.The phosphate-free conversion treatment, by hydrolysis and condensation of polysiloxanes, or Oxsilan®, is carried out by dipping in a bath of Oxsilan® MM0705A at 25 g / l with a withdrawal rate of 25 cm / min, which corresponds to a deposit of about 4 mg Si / m 2 . During this step the metal is not attacked.
The cataphoresis product used is CathoGuard® 800 from BASF, an epoxy-based lacquer. The thickness of the targeted cataphoresis layer is 23 microns; it is obtained by a deposit of 2 minutes in a bath at 30 ° C with a voltage of 260 V, followed by baking for 15 minutes at 175 ° C.

Les résultats de résistance à la corrosion filiforme sur les éprouvettes ayant subi les différents traitements de surface, la cataphorèse, puis le test selon la norme NF EN 3665, avec une durée d'exposition de 1000 heures en enceinte, sont récapitulés au Tableau 3 ci-dessous. Ils sont également reportés dans la dernière colonne du Tableau 2.
La résistance à la corrosion filiforme est jugée bonne (indice O) s'il n'existe pas d'attaque ou bien si un début de corrosion filiforme a lieu sous forme de filaments peu nombreux et d'une longueur inférieure à 2 mm. La résistance à la corrosion filiforme est jugée insuffisante dans le cas contraire (indice X). Tableau 3 Cas Traitement Surface 1 Traitement Surface 2 Traitement Surface 3 1 X O X 2 O O O 3 O O O 4 O O O 5 O O O 6 X O X 7 X O X 8 X X X 9 (AA6016) X O X The results of filiform corrosion resistance on the specimens having undergone the various surface treatments, the cataphoresis, then the test according to standard NF EN 3665, with a exposure time of 1000 hours in the enclosure, are summarized in Table 3 hereof. -Dessous. They are also reported in the last column of Table 2.
The filiform corrosion resistance is considered good (index O) if there is no attack or if a beginning of filiform corrosion takes place in the form of few filaments and a length of less than 2 mm. The resistance to filiform corrosion is considered insufficient in the opposite case (index X). <b> Table 3 </ b> Case Surface Treatment 1 Surface Treatment 2 Surface Treatment 3 1 X O X 2 O O O 3 O O O 4 O O O 5 O O O 6 X O X 7 X O X 8 X X X 9 (AA6016) X O X

On constate que tous les cas testés, à l'exception du cas 8, présentent une bonne résistance à la corrosion filiforme si la cataphorèse est précédée d'un dégraissage et d'une phosphatation (traitement de surface 2). La moins bonne résistance à la corrosion filiforme du cas 8, hors invention, est liée à sa plus forte teneur en cuivre,It is noted that all the cases tested, with the exception of case 8, have good resistance to filiform corrosion if the cataphoresis is preceded by a degreasing and phosphating (surface treatment 2). The poorest filiform corrosion resistance of case 8, apart from the invention, is related to its higher copper content,

Dans les cas des traitements de surface 1 et 3, comportant avant cataphorèse soit un dégraissage seul soit un dégraissage suivi d'un traitement de conversion chimique remplaçant la phosphatation, seuls les cas 2 à 5 selon l'invention présentent une bonne résistance à la corrosion filiforme et en tout cas meilleure notamment que celle du cas de référence en alliage du type AA6016, à l'état métallurgique T4, très couramment utilisé dans l'automobile.In the case of surface treatments 1 and 3, comprising before cataphoresis either a degreasing alone or a degreasing followed by a chemical conversion treatment replacing phosphating, only cases 2 to 5 according to the invention have good corrosion resistance filiform and in any case better than that of the reference case alloy type AA6016, metallurgical T4, very commonly used in the automobile.

Claims (12)

  1. Use of an aluminium alloy sheet for the fabrication of a stamped bodywork part or automobile body structure, also called a "body in white", characterised in that the sheet composition (% by weight) is Si = 0.15 - 0.50; Fe = 0.3 - 0.7; Cu = 0.05 - 0.10; Mn = 1.0 - 1.5; other elements < 0.05 each and < 0.15 total, the remainder being aluminium, and in that said sheet has a yield stress Rp0.2 greater than or equal to 60 MPa and an elongation in uniaxial tension A80 greater than or equal to 34%.
  2. Use according to claim 1, characterised in that said sheet has a Hole Expansion Ratio (HER) of more than 50.
  3. Use according to either claim 1 or 2, characterised in that said hole expansion ratio is greater than or equal to 55.
  4. Use according to one of claims 1 to 3, characterised in that the composition of said sheet (% by weight) is:
    Si = 0.15 - 0.50; Fe = 0.3 - 0.7; Cu = 0.05 - 0.10; Mn = 1.0 - 1.5; other elements < 0.05 each and < 0.15 total, the remainder being aluminium.
  5. Use according to one of claims 1 to 4, characterised in that the Fe content of said sheet is between 0.5 and 0.7%.
  6. Use according to one of claims 1 to 5, characterised in that the Si content of said sheet is between 0.15 and 0.30%.
  7. Use according to one of claims 1 to 6, characterised in that the Mn content of said sheet is between 1.0 and 1.2%, and preferably between 1.1 and 1.2%.
  8. Use according to one of claims 1 to 7, characterised in that after the degreasing treatment alone or the degreasing treatment followed by phosphate-free conversion of said sheet by hydrolysis and condensation of polysiloxanes, and then cataphoresis, the filaments formed during the test of resistance to filiform corrosion according to standard NF EN3665 with a duration of 1000 hours in the chamber, are less than 2 mm long.
  9. Use according to one of claims 1 to 8 for the fabrication of a stamped bodywork part or automobile body structure, characterised in that it comprises the following steps:
    Continuous or semi-continuous vertical casting of a slab and scalping of said slab with composition (% by weight):
    Si = 0.15 - 0.50; Fe = 0.3 - 0.7; Cu = 0.05 - 0.10; Mn = 1.0 - 1.5; other elements < 0.05 each and < 0.15 total, the remainder being aluminium,
    Homogenisation at a temperature of not less than 600°C for at least 5 hours, followed by controlled cooling to a temperature of 550°C to 450°C in less than 7 hours, followed by cooling to ambient temperature in less than 24 hours,
    Heating again to a temperature of 480 to 530°C with a temperature rise taking at least 8 hours, hot rolling, cooling and then cold rolling and annealing at a temperature of at least 350°C,
    Work hardening, typically be flattening under tension or between rollers using a skin pass, with a ratio of between 1% and 10%,
    Chemical stripping of the Mechanically Disturbed Layer (MDL) or the Beilby layer,
    Stamping of said sheet obtained to obtain the bodywork part or automobile body structure.
  10. Use according to one of claims 1 to 9, characterised in that the work hardening ratio of said sheet is between 1% and 5%.
  11. Use according to one of claims 1 to 10, characterised in that the chemical stripping of said sheet is done after alkaline degreasing in an acid environment, with a mass loss of said sheet equal to at least 0.2 g/m2 on each face.
  12. Stamped bodywork part or automobile body structure, characterised in that it is obtained by the use of a sheet according to one of claims 1 to 11.
EP14758586.3A 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicle body Active EP3019637B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP17162984.3A EP3199655A3 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicule body
DE14758586.3T DE14758586T1 (en) 2013-07-11 2014-07-09 Aluminum alloy sheet for the structure of a motor vehicle

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1301644A FR3008427B1 (en) 2013-07-11 2013-07-11 ALUMINUM ALLOY SHEET FOR AUTOMOBILE BODY STRUCTURE
PCT/FR2014/000160 WO2015004340A1 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicle body

Related Child Applications (2)

Application Number Title Priority Date Filing Date
EP17162984.3A Division-Into EP3199655A3 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicule body
EP17162984.3A Division EP3199655A3 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicule body

Publications (2)

Publication Number Publication Date
EP3019637A1 EP3019637A1 (en) 2016-05-18
EP3019637B1 true EP3019637B1 (en) 2017-05-03

Family

ID=49619983

Family Applications (2)

Application Number Title Priority Date Filing Date
EP17162984.3A Withdrawn EP3199655A3 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicule body
EP14758586.3A Active EP3019637B1 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicle body

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP17162984.3A Withdrawn EP3199655A3 (en) 2013-07-11 2014-07-09 Sheet made of aluminum alloy for the structure of a motor vehicule body

Country Status (10)

Country Link
US (1) US10253402B2 (en)
EP (2) EP3199655A3 (en)
JP (1) JP6625530B2 (en)
KR (1) KR20160030563A (en)
CN (1) CN105378125B (en)
BR (1) BR112016000278B1 (en)
DE (2) DE17162984T1 (en)
FR (1) FR3008427B1 (en)
RU (1) RU2690253C2 (en)
WO (1) WO2015004340A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BR112017003259A2 (en) * 2014-09-12 2017-11-28 Novelis Inc aluminum alloy, bottle, tin, method to produce a metal sheet, and, product.
WO2017120117A1 (en) 2016-01-08 2017-07-13 Arconic Inc. New 6xxx aluminum alloys, and methods of making the same
CN106244918B (en) 2016-07-27 2018-04-27 宝山钢铁股份有限公司 A kind of 1500MPa grades of high strength and ductility automobile steel and its manufacture method
JP7053785B2 (en) * 2017-07-26 2022-04-12 アーコニック テクノロジーズ エルエルシー Preparation methods based on roll coating of aluminum alloys for adhesive bonding, and related products

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH036348A (en) * 1989-06-03 1991-01-11 Kobe Steel Ltd Aluminum alloy for automobile panel excellent in chemical conversion treating property and its production
JP3063020B2 (en) * 1992-11-17 2000-07-12 古河電気工業株式会社 Aluminum alloy plate excellent in strength and deep drawability and method for producing the same
JP2001254136A (en) * 2000-03-09 2001-09-18 Kobe Steel Ltd Aluminum alloy sheet for automotive panel inner material, and automotive inner panel
JP2001266264A (en) 2000-03-17 2001-09-28 Yazaki Corp Device and method for detecting fire
JP2001262264A (en) * 2000-03-21 2001-09-26 Kobe Steel Ltd Al-Mg-Si SERIES Al ALLOY SHEET EXCELLENT IN TOUGHNESS AND BENDABILITY
JP3685973B2 (en) * 2000-03-23 2005-08-24 株式会社神戸製鋼所 Al-Mg-based Al alloy plate with excellent formability
DE10037303A1 (en) 2000-07-28 2002-02-21 Thyssenkrupp Technologies Ag Method of manufacturing a door of a motor vehicle and frameless door manufactured by this method
JP2003305503A (en) 2002-04-09 2003-10-28 Mitsubishi Alum Co Ltd Highly formable aluminum alloy plate and method for producing the same
US20050000609A1 (en) * 2002-12-23 2005-01-06 Butler John F. Crash resistant aluminum alloy sheet products and method of making same
FR2851579B1 (en) 2003-02-26 2005-04-01 Pechiney Rhenalu METHOD OF PADDING WITH ALLOY PARTS A1-Mg
FR2856368B1 (en) * 2003-06-18 2005-07-22 Pechiney Rhenalu BODY PIECE OF AUTOMOBILE BODY IN ALLOY SHEET AI-SI-MG FIXED ON STRUCTURE STEEL
US20060042727A1 (en) * 2004-08-27 2006-03-02 Zhong Li Aluminum automotive structural members
JP5247071B2 (en) * 2007-06-20 2013-07-24 住友軽金属工業株式会社 Aluminum alloy plate for press forming
EP2156945A1 (en) * 2008-08-13 2010-02-24 Novelis Inc. Clad automotive sheet product
JP4993141B2 (en) * 2008-11-18 2012-08-08 日本軽金属株式会社 Sandwich panel
EP2270249B2 (en) 2009-06-30 2020-05-27 Hydro Aluminium Deutschland GmbH AlMgSi-sheet for applications with high shaping requirements
CN103060632A (en) * 2012-12-18 2013-04-24 莫纳什大学 Aluminum alloy for automotive body and heat treatment method
PT2770071T (en) * 2013-02-21 2017-04-19 Hydro Aluminium Rolled Prod Aluminium alloy for the production of semi-finished products or components for motor vehicles, method for producing an aluminium alloy strip from this aluminium alloy and aluminium alloy strip and uses thereof

Also Published As

Publication number Publication date
BR112016000278B1 (en) 2020-02-04
FR3008427B1 (en) 2015-08-21
US20160168677A1 (en) 2016-06-16
EP3019637A1 (en) 2016-05-18
DE14758586T1 (en) 2016-07-14
EP3199655A2 (en) 2017-08-02
DE17162984T1 (en) 2017-09-21
US10253402B2 (en) 2019-04-09
JP2016525630A (en) 2016-08-25
KR20160030563A (en) 2016-03-18
CN105378125A (en) 2016-03-02
RU2016104405A3 (en) 2018-06-01
CN105378125B (en) 2018-09-07
JP6625530B2 (en) 2019-12-25
RU2016104405A (en) 2017-08-16
WO2015004340A1 (en) 2015-01-15
EP3199655A3 (en) 2017-08-30
FR3008427A1 (en) 2015-01-16
RU2690253C2 (en) 2019-05-31

Similar Documents

Publication Publication Date Title
EP3303646B1 (en) Metal sheet for a motor vehicle body having high mechanical strength
EP1472380B1 (en) Al-si-mg alloy sheet metal for motor car body outer panel
EP2750882B1 (en) Composite aluminium sheet for automotive body shop
EP3362282B1 (en) Structural component of a motor vehicle shell offering an excellent compromise between mechanical strength and crash resistance
FR2926564A1 (en) CLOTHING TOOL
EP3384060B1 (en) Highly rigid thin sheet metal for car body
EP3019637B1 (en) Sheet made of aluminum alloy for the structure of a motor vehicle body
EP1633900B1 (en) Roof top of a car body made of an al-si-mg sheet metal alloy fixed to a steel frame
FR2922222A1 (en) Sheet composite material made of aluminum alloy for components of automobile bodywork, comprises a sheet of plating applied on two sides of a core by roll bonding
WO2002040729A1 (en) Method for producing an aluminium alloy plated strip for making brazed heat exchangers
CA3057728A1 (en) Improved method for producing a motor vehicle body structure component
EP3555331B1 (en) Aluminium alloy for laser welding without filler wire
EP4355923A1 (en) Strip made of 6xxx alloy and manufacturing process
WO2023094773A1 (en) Strip made of 6xxx alloy and manufacturing process

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: 20160208

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

REG Reference to a national code

Ref country code: DE

Ref legal event code: R210

Ref document number: 602014009472

Country of ref document: DE

Ref legal event code: R210

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: CONSTELLIUM NEUF-BRISACH

DAX Request for extension of the european patent (deleted)
REG Reference to a national code

Ref country code: DE

Ref legal event code: R079

Ref document number: 602014009472

Country of ref document: DE

Free format text: PREVIOUS MAIN CLASS: C22C0021000000

Ipc: B22D0011000000

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RIC1 Information provided on ipc code assigned before grant

Ipc: C22C 21/00 20060101ALI20161125BHEP

Ipc: C22C 21/08 20060101ALI20161125BHEP

Ipc: C21D 1/26 20060101ALI20161125BHEP

Ipc: B22D 11/00 20060101AFI20161125BHEP

Ipc: C22F 1/00 20060101ALI20161125BHEP

Ipc: B22D 21/00 20060101ALI20161125BHEP

Ipc: C22F 1/047 20060101ALI20161125BHEP

Ipc: B22D 11/04 20060101ALI20161125BHEP

Ipc: C22F 1/04 20060101ALI20161125BHEP

Ipc: B22D 11/041 20060101ALI20161125BHEP

Ipc: C22F 1/043 20060101ALI20161125BHEP

Ipc: C22C 21/02 20060101ALI20161125BHEP

INTG Intention to grant announced

Effective date: 20161216

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602014009472

Country of ref document: DE

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 889416

Country of ref document: AT

Kind code of ref document: T

Effective date: 20170515

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: FRENCH

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602014009472

Country of ref document: DE

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 4

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20170503

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

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

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170803

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170804

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170903

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170803

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602014009472

Country of ref document: DE

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

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Effective date: 20180206

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

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

Ref country code: IE

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

Effective date: 20170709

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

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20170731

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

Ref country code: LU

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

Effective date: 20170709

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 5

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

Ref country code: BE

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

Effective date: 20170731

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

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20140709

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

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

REG Reference to a national code

Ref country code: AT

Ref legal event code: UEP

Ref document number: 889416

Country of ref document: AT

Kind code of ref document: T

Effective date: 20170503

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

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20170503

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

Ref country code: TR

Payment date: 20220628

Year of fee payment: 9

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

Ref country code: IT

Payment date: 20230720

Year of fee payment: 10

Ref country code: GB

Payment date: 20230727

Year of fee payment: 10

Ref country code: CH

Payment date: 20230802

Year of fee payment: 10

Ref country code: AT

Payment date: 20230621

Year of fee payment: 10

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

Ref country code: FR

Payment date: 20230725

Year of fee payment: 10

Ref country code: DE

Payment date: 20230727

Year of fee payment: 10