Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/02—Making non-ferrous alloys by melting
  • C22C1/026—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
• • 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

Definitions

• the present invention relates to a method for producing an alloy strip with a recycled aluminum content of up to 100%.
• the recycled aluminum is "post consumer recycled” (PCR) aluminum (according to DIN EN ISO 14021:2016).
• PCR post consumer recycled aluminum
• the alloy strip produced with a proportion of recycled aluminum is suitable for the production of slugs.
• a " slug” is a base material for the packaging industry, which is processed into tubes, cans (e.g. aerosol cans), bottles, but also a base material for the accessories industry, which is used for electronic housings, fuel filter housings, capacitor cups, heat sinks and the like is processed, and consists mainly of aluminum (according to DIN EN 570:2007). Slugs are manufactured in the desired shape, wall thickness and strength by strip casting and stamping. The further processing into cans, tubes, bottles, etc. takes place from slugs by cold extrusion. In most cases, slugs are stamped from pure aluminum or sawn from rods, but aluminum alloys with other alloying elements such as silicon and magnesium are sometimes also used (see Literature-1).
• packaging slugs are divided into “ packaging slugs " and " technical slugs ".
• Packaging slugs for tubes and cans are made exclusively from certain aluminum alloys (alloys of the 1000 and 3000 standards, eg EN AW 1050, EN AW 1070, EN AW 3102 and EN AW 3207) by strip casting and stamping.
• Technical slugs for, for example, electronics housings, fuel filter housings, condenser cups and heat sinks can be made from a wide variety of alloys (including alloys of the 1000, 3000 and 6000 standards).
• alloys with an aluminum content of at least 99.5% (EN AW 1050) or with an aluminum content of at least 99.7% (EN AW 1070) are mainly used (according to European standard EN 573-3).
• Materials of this type can easily be formed by extrusion and experience an increase in strength through cold forming during an extrusion process. Due to these advantageous properties, these alloys cover the majority of the total requirement in the area of packaging slugs and partly also in the area of technical slugs.
• alloy slugs made from aluminum alloys with a manganese content of 0.2% (EN AW 3102) or with a manganese content of 0.6% (EN AW 3207). Alloys of this type have a significantly higher basic hardness and are therefore more likely to be used for more special products that have to withstand higher internal pressure. Due to the higher strength of these alloys, thinner wall thicknesses can be achieved in aerosol cans and housings for technical applications.
• the alloys are first produced in strips, which serve as the starting material for the production of slugs, for example.
• a typical process flow in the production of cast strip includes charging a furnace with feedstock, melting the material, alloying the melt, treating the melt, casting as strip, hot rolling the strip, cold rolling the strip, and coiling the strip.
• Additional process sequences in the production of slugs from cast strip include stamping the slugs from an uncoiled strip, soft annealing the slugs, treating the surface of the slugs (e.g., blasting, scouring, tumbling, barrel finishing, etc.), packing the slugs, and finally storing the slugs.
• recycling material can be added to the manufacturing process.
• a return material that can be added during the production of an alloy can be divided into two types.
• Waste before use or " Post Industrial Recycled” (abbreviation: PIR).
• PIR Post Industrial Recycled
• This term includes, for example, pressed screens from slug production with primary aluminum as the starting material.
• the PCR mainly involves contaminated waste or scrap to which organic substances (e.g. oil, paint, residues from the filling, etc.) adhere.
• organic substances e.g. oil, paint, residues from the filling, etc.
• Processing without pre-treatment is only possible if a melting furnace with the appropriate technology is used. Without using a furnace, a rework step is necessary. Contaminated scrap is remelted in a facility with the appropriate technology. Through the remelting Ingots are formed (so-called "sows "), which can then be used in the melting furnace of the rotary casting plant without any problems.
• PCR aluminum has hardly been processed as a recycle material.
• alloys are mainly manufactured from PIR aluminum due to the following advantages over the use of PCR aluminum.
• Pure alloys such as EN AW 1050 and EN AW 1070 have a similar chemical composition and can also be mixed if necessary, which results in simple logistics.
• primary aluminum is used as the basis and alloyed with appropriate master alloys.
• primary aluminum and an AlMn master alloy are used to achieve the EN AW 3102 alloy.
• PIR aluminum is used as a return material
• the mixture of input materials consists of Primary aluminum and a master alloy (e.g. AlMn to obtain the EN AW 3102 alloy) and, for example, pressed screens made from the same alloy (from a previous production).
• EN AW 1050 and EN AW 1070 for example, a typical ratio of 60 to 70% primary aluminum (e.g. ingots of quality P1020 according to the DIN EN 576 standard) to 30 to 40% secondary aluminum (PIR Process scrap, e.g. stamped grid scrap from slug production, each made of the same alloy) is used.
• primary aluminum e.g. ingots of quality P1020 according to the DIN EN 576 standard
• secondary aluminum PIR Process scrap, e.g. stamped grid scrap from slug production, each made of the same alloy
• the alloys EN AW 3102 and EN AW 3207 for example, a typical ratio of 60 to 70% primary aluminum (e.g. ingots in quality P1020 according to the DIN EN 576 standard) to 30 to 40% secondary aluminum (master alloys for alloys and PIR process scrap, e.g. lead frame scrap from slug production, each made from the same alloy).
• primary aluminum e.g. ingots in quality P1020 according to the DIN EN 576 standard
• secondary aluminum master alloys for alloys and PIR process scrap, e.g. lead frame scrap from slug production, each made from the same alloy.
• Literature-2 ( EP 3 144 403 B1 ) discloses prior art aluminum alloys made by blending 10 to 60% PIR aluminum alloys (grades: 3105, 3004, 3003, 3103, or 3104) with 40 to 90% pure aluminum (grades 1070 and 1050).
• the input material for the production of aluminum alloys largely determines the level of CO 2 emissions.
• the primary metal production from bauxite is very energy-intensive due to the electrolysis and therefore causes a high CO 2 load.
• the CO 2 load when using primary metal is therefore significantly higher than when using recycled material.
• the CO 2 pollution in Europe in relation to produced primary aluminum is 6.7 kg(CO 2 )/kg(Al) and primary aluminum used is 8.7 kg(CO 2 )/kg(Al).
• the CO 2 load from the use of primary aluminum is as high as 18 kg(CO 2 )/kg(Al) (see Table 1, Literature-3).
• CO 2 pollution PRIMARY ALUMINUM [kg(CO 2 )/kg(Al)] primary aluminum used (worldwide) 18 Primary aluminum produced (Europe-wide) 6.7 primary aluminum used (across Europe) 8.7 SECONDARY ALUMINUM Collecting, cleaning, sorting and transporting (throughout Germany) 0.625 possibly reworking the cycle material with organic adhesions; Conversion companies, certified according to ASI (Aluminum Stewardship Initiative)) 0.35
• the CO 2 load of a starting material that is charged, for example, in a melting/casting furnace of a strip caster is approx. 0.625 kg(CO 2 )/kg(Al) in the case of direct use and in the case of an additionally processed material approx. 0.975 kg(CO 2 )/kg(Al).
• packaging slugs which are used, for example, as a starting material for the production of cans and tubes
• technical slugs which are used, for example, for the production of housings (e.g. fuel filter housings in cars) or similar
• housings e.g. fuel filter housings in cars
• pure aluminum alloys according to EN AW 1050A and EN AW 1070A
• Such pure alloys can be produced without any problems using ingots and/or single-variety scrap, for example stamped skeletons.
• a typical manufacturing process uses 60% primary aluminum and 40% lead frame.
• the lower the alloy content (approx. max. 0.5% total), the easier it is to set the standardized chemical composition through the use of primary aluminum.
• the material can be formed more easily and the required forming force is therefore lower. This has a positive effect on tool wear.
• the present method was invented in order to use the most sustainable possible material cycles in production and to produce products which are essentially produced from secondary material with minimal CO 2 emissions.
• the present invention solves the above problem and contributes to sustainability by using up to 100% of recyclable material types (secondary aluminium).
• the present invention advantageously uses types of cycle material that are currently sufficiently available on the market, since they occur as a result of the process and are therefore inevitable or have a short useful life.
• the present invention enables the use of different types of circuit material in different proportions with a wide tolerance (in terms of weight %).
• Alloying elements and in particular the specific manganese content of the alloy according to the invention lead to an increase in strength, which enables new possibilities in the design of the wall thicknesses (in particular a lower wall thickness), and as a result of which considerable savings potential in the use of materials in the impact extrusion process and ultimately lighter end products (e.g. low empty can weight) can be achieved .
• a method of making alloy strip from recycled aluminum or PCR aluminum provided, wherein no alloying elements are added and the method comprises the following steps.
• the composition of individual batches of the starting materials consisting of aluminum such as ingots ( “primary aluminum ”) and aluminum cycle materials such as scrap before use (PIR) e.g. stamped skeleton and scrap after use (PCR) such as wire scrap or sows from various types of scrap, to achieve an alloy with the desired composition (“ RAW-C”,”Recycled Aluminum Wutöschingen-Container ").
• PIR scrap before use
• PCR scrap after use
• wire scrap or sows from various types of scrap to achieve an alloy with the desired composition
• RAW-C Scrap before use
• PCR scrap after use
• the determination is based on a theoretical calculation of the chemical composition of the target alloy, with a mixing ratio being determined on the basis of the respective chemical compositions of the individual input material types used, in particular scrap types such as beverage cans, off-set sheet metal or wire scrap.
• PCR aluminum which is used in the production of an alloy, can be obtained in the form of sows as starting material from reworking foundries.
• a starting material can consist of 40% beverage cans and 60% off-set sheet metal, but separate remelting is also possible, so that the starting material in the form of sows consists of 100% beverage cans or 100% off-set sheet metal.
• a strip casting line with the batches of the starting materials according to the previous step according to the shape of the starting material or input material first, small-sized scraps such as stamping skeleton or cube-shaped wire scrap, and then the large-sized scraps such as sows (about 800kg/pc) ) loaded.
• a system can, for example consist of a separate melting furnace and a downstream casting furnace, or of a combined melting/casting furnace.
• the mixture is then melted in the furnace.
• the energy can be supplied, for example, by a burner on the furnace roof.
• the ceiling temperature before loading may have a temperature in a range of 700°C to 1000°C, preferably in a range of 800°C to 900°C, more preferably in a range of 820°C to 870°C, and in particular has preferably a temperature of 850 °C.
• the ceiling temperature during melting may have a temperature in a range of 800°C to 1000°C, preferably in a range of 900°C to 1000°C, and more preferably in a range of 950°C to 1000°C a temperature of 990° C. is particularly preferred.
• the resulting melt is treated and cleaned, for example, by salt, standing and purge gas treatments to bind non-metallic impurities such as oxides.
• Molten aluminum is cleaned by ceramic filters on the way to the casting plant.
• melt sample a first sample taken after the furnace is fully charged (melt sample) and a second sample taken before pouring (release sample).
• the ceiling temperature during casting may be a temperature in a range of 600°C to 900°C, preferably a temperature in a range of 700°C to 800°C, and more preferably a temperature in a range of 700°C to 750°C have, and particularly preferably has a temperature of 720 ° C, the temperature of the metal, depending on the alloy, a temperature in a range from 700 ° C to 800 ° C, preferably a temperature in a range from 710 ° C to 740°C; and more preferably has a temperature of 730°C.
• the casting temperature depends on the material and is usually above 660 °C.
• the Casting temperature may have a temperature in a range from 660°C to 900°C, preferably in a range from 660°C to 800°C, more preferably in a range between 690°C and 750°C, and most preferably has a temperature of 730 °C.
• the liquid mixture is preferably cast into a tape by rotary casting. Casting takes place continuously via a casting wheel.
• a casting wheel can be made of steel or copper, for example, and have a diameter of 1000 to 1800 mm.
• the temperature of the strip emerging from the plant depends, inter alia, on the strip cross-section and the type of casting wheel, and can be a temperature in a range from 400 °C to 600 °C, preferably a temperature in a range from 450 °C to 550 °C, more preferably a temperature in a range from 470°C to 530°C, and particularly preferably has a temperature of 500°C.
• a strip with a thickness of 16 to 32 mm, for example, is formed from liquid aluminum in the casting gap between the casting strip and the casting wheel.
• the recrystallization temperature depends on the material, and thus a temperature during hot rolling can be in a range of 300°C to 600°C, preferably a temperature in a range of 320°C to 500°C, more preferably a temperature in a range of 370° C to 470 °C can be selected.
• a temperature of 440° C. is particularly preferably selected during hot rolling. This step reduces the initial thickness by 25% to 50%.
• the strip After hot rolling, the strip must be cooled to a maximum of 50°C, more preferably to a temperature not higher than 40°C, and most preferably to a temperature not higher than 30°C, by suitable cooling.
• the cooling gradient is preferably between 800° C. and 1200° C./min, more preferably between 850° C. and 1150° C., particularly preferably between 900° C. and 1100° C.
• a thickness of between 5 mm and 12 mm is achieved, for example.
• a method of producing a recycled aluminum or PCR aluminum slug, wherein no alloying elements are added separately comprising the steps of the first aspect described above and the steps below.
• added separately in this context means that, apart from the types of aluminum pre-material used, which already have alloying elements, no elementary elements of the Al alloy are added.
• the types of primary material used have a total alloy content of approx. 2% to 3%. Since the primary material types bring sufficient alloying elements into the melt, additional alloying by adding alloying elements is not necessary.
• the slugs are produced by stamping the cast strip produced using a suitable stamping tool.
• the slugs are heat treated to remove work hardening caused by rolling and stamping.
• a temperature in a range of 400 °C to 600 °C preferably a temperature in a range of 420 °C to 580 °C, more preferably a temperature in a range of 450 °C to 550 °C can be selected, and most preferably the temperature is 520°C.
• the slug surface is roughened, for example by blasting, scouring and tumbling, in order to enable the slugs to absorb sufficient lubricant for the cold extrusion process.
• a "RAW" alloy produced by the method according to the first or second aspect.
• This alloy has the following composition: Si: 0.05 to 0.40% by weight, Fe: 0.20 to 0.60% by weight, Cu: 0.03 to 0.20% by weight, Mn: 0.16 to 0.50% by weight, Mg: 0.03 to 0.20% by weight, Cr: 0.01 to 0.03% by weight, Zn: 0.01 to 0.06% by weight, Ti: 0.01 to 0.03% by weight, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, Al: Rest.
• an alloy "RAW-C25" according to the third aspect.
• This alloy has the following composition: Si: 0.05 to 0.12% by weight, Fe: 0.20 to 0.30% by weight, Cu: 0.03 to 0.07% by weight, Mn: 0.16 to 0.22% by weight, Mg: 0.03 to 0.07% by weight, Cr 0.005 to 0.03% by weight, Zn 0.01 to 0.04% by weight, Ti 0.005 to 0.03 wt%, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: balance.
• a specific alloy "RAW-C25" according to the fourth aspect.
• This alloy has the following composition: Si: 0.12% by weight, Fe: 0.24% by weight, Cu: 0.05% by weight, Mn: 0.21% by weight, Mg: 0.06% by weight, Cr: 0.005% by weight, Zn: 0.0325% by weight, Ti: 0.01% by weight, Zr: 0.00% by weight, Pb: 0.0005% by weight, Al: Rest.
• an alloy "RAW-C50" according to the third aspect.
• This alloy has the following composition: Si: 0.10 to 0.20% by weight, Fe: 0.28 to 0.40% by weight, Cu: 0.05 to 0.10% by weight, Mn: 0.20 to 0.30% by weight, Mg: 0.05 to 0.10% by weight, Cr: 0.005 to 0.03% by weight, Zn: 0.01 to 0.05% by weight, Ti: 0.005 to 0.03% by weight, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: balance.
• a specific alloy "RAW-C50" according to the sixth aspect.
• This alloy has the following composition: Si: 0.14% by weight, Fe: 0.32% by weight, Cu: 0.07% by weight, Mn: 0.30% by weight, Mg: 0.10% by weight, Cr: 0.01% by weight, Zn: 0.03% by weight, Ti: 0.01% by weight, Zr: 0.00% by weight, Pb: 0.001% by weight, Al: Rest.
• an alloy "RAW-C95" according to the third aspect.
• This alloy has the following composition: Si: 0.15 to 0.40% by weight, Fe: 0.35 to 0.60% by weight, Cu: 0.10 to 0.20% by weight, Mn: 0.25 to 0.50% by weight, Mg: 0.08 to 0.20% by weight, Cr: 0.005 to 0.03% by weight, Zn: 0.01 to 0.06% by weight, Ti: 0.01 to 0.03% by weight, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: balance.
• a specific alloy "RAW-C95" according to the eighth aspect.
• This alloy has the following composition: Si: 0.16% by weight, Fe: 0.45% by weight, Cu: 0.10% by weight, Mn: 0.43% by weight, Mg: 0.15% by weight, Cr: 0.01% by weight, Zn: 0.03% by weight, Ti: 0.02% by weight, Zr: 0.00% by weight, Pb: 0.002% by weight, Al: Rest.
• PCR aluminum is used to produce an alloy according to any aspect of the third to ninth aspects produced by the method according to the first or second aspect.
• PCR aluminum includes aluminum scrap, and/or used beverage cans, and/or sorting scrap containing aluminum, and/or offset sheet metal, and/or wire and cable scrap, and/or profile scrap, and/or reworked aluminum dross your own melt.
• the proportion of the PCR aluminum according to the tenth aspect is between 10% and 100%, between 20% and 100%, between 30% and 100%, between 40% and 100%, between 50% and 100%, between 60% and 100%, between 70% and 100%, between 80% and 100%, between 90% and 100%, or between 95% and 100%.
• the present method was invented in order to use the most sustainable possible material cycles in production and to produce products which are essentially produced from secondary material with minimal CO 2 emissions.
• the method and the alloys produced thereby have advantageous effects in that a proportion of up to 100% of the PCR aluminum can be used and good availability for the continuous supply of the recycle types the market exists.
• the alloys of the present invention result in higher strength in the case of thin-walled housings and variable, good formability in the cold forging process, as a result of which tool wear during stamping remains within an economically justifiable range.
• the average material flow consists of ingots (quality: P1020) and stamped skeleton (according to EN AW 1050A and EN AW 1070A), with the stamped skeleton going to the furnace after the stamping process is supplied again during charging ("charging") (see Fig. 1).
• the general chemical composition of mainly used aluminum alloys EN AW 1050A, EN AW 1070A, and EN AW 3102 is as follows: - Aluminum alloy according to EN AW 1050A: Si: ⁇ 0.25% by weight, Fe: ⁇ 0.40% by weight, Cu: ⁇ 0.05% by weight, Mn: ⁇ 0.05% by weight, Zn: ⁇ 0.07% by weight, Ti: ⁇ 0.05% by weight, and Al: balance.
• - Aluminum alloy according to EN AW 1070A Si: ⁇ 0.20% by weight, Fe: ⁇ 0.25% by weight, Cu: ⁇ 0.03% by weight, Mn: ⁇ 0.03% by weight, Zn: ⁇ 0.07% by weight, Ti: ⁇ 0.05% by weight, and Al: balance.
• - Aluminum alloy according to EN AW 3102 Si: ⁇ 0.40% by weight, Fe: ⁇ 0.70% by weight, Cu: ⁇ 0.10% by weight, Mn: 0.05 to 0.40% by weight, Zn: ⁇ 0.03% by weight, Ti: ⁇ 0.10 wt%, and Al: balance.
• a typical chemical composition of EN AW 1050A alloy is: Si: 0.079% by weight, Fe: 0.258% by weight, Cu: 0.001% by weight, Mn: 0.001% by weight, Mg: 0.001% by weight; Zn: 0.005% by weight; Ti: 0.011% by weight, Cr: 0.001% by weight; Zr: 0.002% by weight; Pb: 0.002% by weight; and Al: 99.62% by weight
• a typical chemical composition of EN AW 1070A alloy is: Si: 0.048% by weight, Fe: 0.161% by weight, Cu: 0.001% by weight, Mn: 0.001% by weight, Mg: 0.001% by weight, Zn: 0.003% by weight, Ti: 0.015% by weight, Cr: 0.001% by weight, Zr: 0.001% by weight, Pb: 0.002% by weight, and Al: 99.74% by weight
• a typical chemical composition of alloy EN AW 3102 is: Si: 0.058% by weight, Fe: 0.180% by weight, Cu: 0.001% by weight, Mn: 0.245% by weight, Mg: 0.000% by weight, Zn: 0.007% by weight, Ti: 0.013% by weight, Cr: 0.001% by weight, Zr: 0.001% by weight, Pb: 0.002% by weight, and Al: 99.47% by weight
• an average material flow consists of stamped skeleton, scrap beverage cans, offset sheet metal and other types of scrap, with the stamped skeleton being returned to the furnace during charging ("charging") after the stamping process. It is particularly advantageous that the production method according to the invention can be used to produce an aluminum alloy which consists of up to 100% recycled material (see FIG. 2).
• mixed, old beverage cans (according to EN 13920-10) and mixed stamped scrap from EN AW 1050A and 1070A (according to EN 13920-2) are supplied as circulating materials.
• RAW-C-II a material flow of the second embodiment
• mixed, old beverage cans accordinging to EN 13920-10
• offset sheet metal accordinging to EN 13920-2
• wire and cable scrap accordinging to EN 13920- 3
• mixed lead frame scrap from EN AW 1050A and 1070A accordinging to EN 13920-2 fed in as circulating materials.
• the chemical composition of the alloy produced by this material flow according to the first embodiment is outside the composition according to the EN 573-3 standard.
• the chemical composition of an alloy resulting from the material flow of the first embodiment is as follows (determined by optical emission spectroscopy or by means of a spark spectrometer): Si: 0.203% by weight, Fe: 0.320% by weight, Cu: 0.067% by weight, Mn: 0.344% by weight, Mg: 0.081% by weight, Zn: 0.020% by weight, Ti: 0.02% by weight, Cr: 0.011% by weight, Zr: 0.002% by weight, Pb: 0.002% by weight, and Al: 98.89% by weight.
• RAW-C-II The chemical composition of an alloy resulting from the material flow of the second embodiment
• Si 0.187% by weight
• Fe 0.479% by weight
• Cu 0.102% by weight
• Mn 0.414% by weight
• Mg 0.076% by weight
• Zn 0.057% by weight
• Ti 0.02% by weight
• Cr 0.011% by weight
• Zr 0.003% by weight
• Pb 0.003% by weight
• Al 98.61% by weight.
• Table 2 shows the mechanical properties of slugs produced from the above starting materials under the same conditions.
• Table 2 Comparison of the mechanical properties of the alloys from the material flows of the first and second embodiment (RAW-CI and RAW-C-II) with the base alloys EN AW 1050A and 1070A and 3102, where Rp0.2 is the yield strength and Rm is the tensile strength (Tensile test according to DIN EN ISO 6892 and hardness test according to DIN EN ISO 6506).
• the results shown in Table 2 show that the hardness of the slugs in the annealed condition in the case of the first embodiment heats (RAW-CI) compared to EN AW 1050A decreased by 23% and 35% respectively compared to EN AW 10170A 35% and 50% higher, respectively, and compared to EN AW 3102 is 17% and 23% higher, respectively.
• the yield strength of the RAW-CI alloy is at least 10 MPa or 19% higher and the yield strength at least 23 MPa or 31% higher than the typical values of the base alloys.
• the results of Table 2 show that the hardness of the slugs in the annealed condition in the case of the heats of the second embodiment (RAW-C-II) compared to EN AW 1050A by 59 and 75% respectively, compared to EN AW 1070A 75 and 94% higher, and compared to EN AW 3102 is 52 and 59% higher.
• the yield strength of the RAW-C-II alloy is at least 15 MPa or 29% higher and the yield strength at least 31 MPa or 41% higher than the typical values of the base alloys.
• the wall thicknesses of cans can be reduced by the alloys of the present invention.
• a lower wall thickness brings the advantage of weight savings, which leads to a reduction in CO 2 during transport. Less CO 2 is already emitted during the production of the primary material due to a reduced use of material, which is a further significant advantage of the present invention with regard to environmental pollution.
• the increased strength of RAW-C alloys is due to the higher Mn content, which has a recrystallization-inhibiting effect. Since the content of the strength-enhancing alloying element Mn in old beverage cans is 0.8 wt% to 1.0 wt%, those according to the invention have a higher Mn content than alloys of standards EN AW 1050 and EN AW 1070, and even partially has a higher Mn content than the EN AW 3102 alloy, which has a Mn content of approx. 0.3% by weight.)
• the chemical composition results from the proportions of different types of cycle material and their chemical composition.
• the availability of a recycle material depends on the production volume, the useful life, and the return rate in the material cycle.
• the mechanical properties of the alloy depend primarily on the chemical composition.
• the limits of individual alloying elements are selected in such a way that a composition suitable for the respective application can be selected in accordance with the requirements for mechanical properties.
• an alloy of the present invention has the chemical composition: Si: 0.05 to 0.40% by weight, Fe: 0.20 to 0.60% by weight, Cu: 0.03 to 0.20% by weight, Mn: 0.16 to 0.50% by weight, Mg: 0.03 to 0.20% by weight, Cr 0.01 to 0.03% by weight, Zn 0.01 to 0.06% by weight, Ti 0.01 to 0.03% by weight, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: Rest.
• an alloy of the first embodiment (“RAW-C25”) has a post-anneal hardness of 24+3 HB and the following composition: Si: 0.05 to 0.12% by weight, Fe: 0.20 to 0.30% by weight, Cu: 0.03 to 0.07% by weight, Mn: 0.16 to 0.22% by weight, Mg: 0.03 to 0.07% by weight, Cr 0.005 to 0.03% by weight, Zn 0.01 to 0.04% by weight, Ti 0.005 to 0.03 wt%, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: balance.
• a specific example of an alloy of the first embodiment (“RAW-C25”) has the following composition of starting materials: - 75% ingots (P1020A according to DIN EN 576) with the composition: Si: 0.08% by weight, Fe: 0.15% by weight, Cu: 0.00% by weight, Mn: 0.00% by weight, Mg: 0.00% by weight, Cr: 0.00% by weight, Zn: 0.03% by weight, Ti: 0.00% by weight, Zr: 0.00% by weight, Pb: 0.00% by weight, and Al: remainder; and - 25% beverage can scrap with the composition: Si: 0.24% by weight, Fe: 0.52% by weight, Cu: 0.19% by weight, Mn: 0.84% by weight, Mg: 0.32% by weight, Cr: 0.02% by weight, Zn: 0.04% by weight, Ti: 0.02% by weight, Zr: 0.00% by weight, Pb: 0.002% by weight, and Al: rest.
• the alloy of the first embodiment (“RAW-C25”) resulting from this specific composition has the following composition (determined by optical emission spectroscopy): Si: 0.12% by weight, Fe: 0.24% by weight, Cu: 0.05% by weight, Mn: 0.21% by weight, Mg: 0.06% by weight (taking into account the burn-up), Cr: 0.005% by weight, Zn: 0.0325% by weight, Ti: 0.01% by weight, Zr: 0.00% by weight, Pb: 0.0005% by weight, and Al: rest.
• an alloy of the second embodiment has a hardness of 28+2 HB and the following composition: Si: 0.10 to 0.20% by weight, Fe: 0.28 to 0.40% by weight, Cu: 0.05 to 0.10% by weight, Mn: 0.20 to 0.30% by weight, Mg: 0.05 to 0.10% by weight, Cr: 0.005 to 0.03% by weight, Zn: 0.01 to 0.05% by weight, Ti: 0.005 to 0.03% by weight, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: rest.
• a specific example of an alloy of the second embodiment (“RAW-C50”) has the following composition of starting materials: - 50% ingots (P1020A according to DIN EN 576) with the composition: Si: 0.08% by weight, Fe: 0.15% by weight, Cu: 0.00% by weight, Mn: 0.00% by weight, Mg: 0.00% by weight, Cr: 0.00% by weight, Zn: 0.03% by weight, Ti: 0.00% by weight, Zr: 0.00% by weight, Pb: 0.00% by weight, and Al: remainder; - 35% beverage can scrap with the composition: Si: 0.24% by weight, Fe: 0.52% by weight, Cu: 0.19% by weight, Mn: 0.84% by weight, Mg: 0.32% by weight, Cr: 0.02% by weight, Zn: 0.04% by weight, Ti: 0.02% by weight, Zr: 0.00% by weight, Pb: 0.002% by weight, and Al: remainder; and - 15% off-set sheets with the composition Si: 0.08%
• the alloy of the second embodiment (“RAW-C50”) resulting from this specific composition has the following composition (determined by optical emission spectroscopy): Si: 0.14% by weight, Fe: 0.32% by weight, Cu: 0.07% by weight, Mn: 0.30% by weight, Mg: 0.10% by weight (taking into account the burn-up), Cr: 0.01% by weight, Zn: 0.03% by weight, Ti: 0.01% by weight, Zr: 0.00% by weight, Pb: 0.001% by weight, and Al: rest.
• an alloy of the third embodiment (“RAW-C95”) has a hardness of 32+4 HB and the following composition: Si: 0.15 to 0.40% by weight, Fe: 0.35 to 0.60% by weight, Cu: 0.10 to 0.20% by weight, Mn: 0.25 to 0.50% by weight, Mg: 0.08 to 0.20% by weight, Cr: 0.005 to 0.03% by weight, Zn: 0.01 to 0.06% by weight, Ti: 0.01 to 0.03% by weight, Zr: ⁇ 0.03% by weight, Pb: ⁇ 0.005% by weight, and Al: balance.
• a specific example of an alloy of the third embodiment (“RAW-C95”) has the following composition of starting materials (composition: 95% recycle and 5% primary metal): - 5% ingots (P1020A according to DIN EN 576) with the composition: Si: 0.08% by weight, Fe: 0.15% by weight, Cu: 0.00% by weight, Mn: 0.00% by weight, Mg: 0.00% by weight, Cr: 0.00% by weight, Zn: 0.03% by weight, Ti 0.00% by weight, Zr: 0.00% by weight, Pb: 0.00% by weight, and Al: remainder; - 50% beverage can scrap with the composition: Si: 0.24% by weight, Fe: 0.52% by weight, Cu: 0.19% by weight, Mn: 0.84% by weight, Mg: 0.32% by weight, Cr: 0.02% by weight, Zn: 0.04% by weight, Ti: 0.02% by weight, Zr: 0.00% by weight, Pb: 0.002% by weight, and Al: remainder; - 35%
• the alloy of the third embodiment (“RAW-C95”) resulting from this specific composition has the following composition (determined by optical emission spectroscopy): Si: 0.16% by weight, Fe: 0.45% by weight, Cu: 0.10% by weight, Mn: 0.43% by weight, Mg: 0.15% by weight (taking into account the burn-up), Cr: 0.01% by weight, Zn: 0.03% by weight, Ti: 0.02% by weight, Zr: 0.00% by weight, Pb: 0.002% by weight, and Al: rest.
• the alloys of the present invention offer the advantage of higher strength compared to the prior art. Due to the possibility of low wall thicknesses or higher possible internal pressures with the same wall thickness and the associated lower use of materials, considerable savings can be achieved in production and ultimately in the end products.

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• 2021
  • 2021-08-04 EP EP21189626.1A patent/EP4130306A1/fr active Pending

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