CA1133805A - Method for solution heat treatment of 6201 aluminum alloy - Google Patents
Method for solution heat treatment of 6201 aluminum alloyInfo
- Publication number
- CA1133805A CA1133805A CA342,603A CA342603A CA1133805A CA 1133805 A CA1133805 A CA 1133805A CA 342603 A CA342603 A CA 342603A CA 1133805 A CA1133805 A CA 1133805A
- Authority
- CA
- Canada
- Prior art keywords
- temperature
- bar
- rod
- cast
- cast bar
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 45
- 238000010438 heat treatment Methods 0.000 title claims abstract description 10
- 229910000838 Al alloy Inorganic materials 0.000 title claims description 33
- 238000005266 casting Methods 0.000 claims abstract description 37
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 36
- 239000000956 alloy Substances 0.000 claims abstract description 36
- 229910052751 metal Inorganic materials 0.000 claims abstract description 34
- 239000002184 metal Substances 0.000 claims abstract description 34
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 32
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 31
- 239000000047 product Substances 0.000 claims abstract description 18
- 238000001556 precipitation Methods 0.000 claims abstract description 16
- 238000001816 cooling Methods 0.000 claims abstract description 9
- 239000002244 precipitate Substances 0.000 claims abstract description 8
- 229910002065 alloy metal Inorganic materials 0.000 claims abstract description 7
- 238000004519 manufacturing process Methods 0.000 claims abstract description 7
- 230000032683 aging Effects 0.000 claims abstract description 5
- 238000005204 segregation Methods 0.000 claims abstract 4
- 230000000977 initiatory effect Effects 0.000 claims abstract 3
- 238000010791 quenching Methods 0.000 claims description 21
- 238000005275 alloying Methods 0.000 claims description 19
- 230000000171 quenching effect Effects 0.000 claims description 13
- 230000008569 process Effects 0.000 claims description 11
- 239000010703 silicon Substances 0.000 claims description 11
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 10
- 229910052749 magnesium Inorganic materials 0.000 claims description 10
- 239000011777 magnesium Substances 0.000 claims description 10
- 229910052710 silicon Inorganic materials 0.000 claims description 10
- 238000009749 continuous casting Methods 0.000 claims description 9
- 238000005098 hot rolling Methods 0.000 claims description 4
- 239000003921 oil Substances 0.000 claims description 4
- 235000010210 aluminium Nutrition 0.000 claims 17
- 150000002739 metals Chemical class 0.000 claims 12
- 239000010953 base metal Substances 0.000 claims 2
- 238000002844 melting Methods 0.000 claims 2
- 230000008018 melting Effects 0.000 claims 2
- 230000009850 completed effect Effects 0.000 claims 1
- 239000012467 final product Substances 0.000 claims 1
- 238000005096 rolling process Methods 0.000 description 20
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 6
- YTHCQFKNFVSQBC-UHFFFAOYSA-N magnesium silicide Chemical compound [Mg]=[Si]=[Mg] YTHCQFKNFVSQBC-UHFFFAOYSA-N 0.000 description 6
- 229910021338 magnesium silicide Inorganic materials 0.000 description 6
- 238000003303 reheating Methods 0.000 description 6
- 239000007787 solid Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 4
- 238000010923 batch production Methods 0.000 description 3
- 239000002826 coolant Substances 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 229910000676 Si alloy Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- MCWXGJITAZMZEV-UHFFFAOYSA-N dimethoate Chemical compound CNC(=O)CSP(=S)(OC)OC MCWXGJITAZMZEV-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
-
- 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
- C22F1/05—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 of the Al-Si-Mg type, i.e. containing silicon and magnesium in approximately equal proportions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B3/003—Rolling non-ferrous metals immediately subsequent to continuous casting, i.e. in-line rolling
Abstract
ABSTRACT OF THE DISCLOSURE
An improved method of continuously manufacturing a hot formed heat treatable aluminum base alloy product having a substantially extended shelf life comprising casting a molten aluminum base alloy metal, cooling the cast metal during casting at a rate at which inverse segregation will be substantially minimized, raising the temperature of the cast metal prior to the initiation of the step of hot forming the cast metal to a temperature above the temperature level at which the alloy metals will substantially precipitate, subsequently reducing the metal temperature from the solutionizing temperature of the metal to a temperature at which no substantial immediate precipitation occurs within a time interval before which any substantial precipitation occurs and controlling the solution heat treatment time and temperature such that said product has controlled precipitation during natural aging.
An improved method of continuously manufacturing a hot formed heat treatable aluminum base alloy product having a substantially extended shelf life comprising casting a molten aluminum base alloy metal, cooling the cast metal during casting at a rate at which inverse segregation will be substantially minimized, raising the temperature of the cast metal prior to the initiation of the step of hot forming the cast metal to a temperature above the temperature level at which the alloy metals will substantially precipitate, subsequently reducing the metal temperature from the solutionizing temperature of the metal to a temperature at which no substantial immediate precipitation occurs within a time interval before which any substantial precipitation occurs and controlling the solution heat treatment time and temperature such that said product has controlled precipitation during natural aging.
Description
11338(~5 l . _ 7, --~ ~ BACKGROUND OF TI~E INVENTION
.
6201 Aluminum Alloy is a high strength aluminum maq- !
nesium silicon alloy which in wire form and in the heat treated condition has a tensile strength of over 46,000 PSI, elongation greater than 3 percent, and an electrical conductivity greater . than 52.5 percent IACS. In the past, 6201 Aluminum Alloy redraw I
~ rod and similar aluminum alloy redraw rods have been manufactured -` for commercial use ~y a plurality of separate steps .which include ~ DC casting an aluminum in~ot reheating thc in~ot to about 700 L0 ~: to 850F, hot rolling the cast ingot to redraw rod and solution-izing the rod at a temperature of approximately 1000F and water quenching the rod. The rod is cold drawn to form wire, and the wire is artificially aged ~t tR~p~AtUres ~QtwQen 25~ a~d 450F. This proccdure is capable of producing wire having ..... ...tensile.strength and electrical conductivity characteristics which are sim~lar to or in excess of those for 6201 Aluminum. ?
While the foregoing procedure produces an acceptable product, such a ~atch process or non-continuous casting process, is ~apable of producing only a limite-3 amount of rod; that is, ~ the given size billet will produce on1y a corresponding mass of rod, and the lengths of separately produced rod must be welded together to form longer lengths of rod. When the billet is reheated and rolled to form rod, it is customary to crop tne leadtng end of the rod since it is of an inferior quality. Tl~us a su~stantial amount of waste is experienced in the formcr procedure. An e~ongated rod which comprises several lengths of batch produce~ products welded together will include poor g~ain ,, . _ . .. .. . .
~i33805 structure at the places where it is welded together, which affects tensile strength and conductivity. Furthermore, it is virt~ally impossible to create identical conditions in the reheating and rolling of different billets, and the lengths of rod welded together will usually have different grain characteristics.
In order to reheat the rod in this batch system, the rod must be carefully handled in order to achieve uniform heating and in order to produce a uniform product. For instance, the oven in which the rod is placed for solutionizing must ~reate relatively e~en heat distribution in order that the rod be uniformly heated. ~urthermore, the rod usually must be arranged so that there is enough circulation of air or gases n the oven between the coils to insure proper heat distribution. It is customary to place individual coils of ro~ on porta~le racks which space the coils from cach other for this purpose; however, the racks occupy space in the oven and reduce the volume of rod which can be heated. Whilo the purpose of reheating the rod is to solutionize the rod, it is desirable to keep the rod from reaching a temperature substantially higher than its solutionizing temperature since the overlapping portions of the rod in the coils in the rod tend to hecome tacked or welded together. This tacking together of the portions of the rod creates surface ~lemishes on the rod when pulled apart, and frequently the coils remain tacked together so that several coils of rod tend to pay out together. Thus even heat distribution within the solutionizing oven is a practical necessity so that the rod can be rapidly and uni~ormly solutionized to hold the hazard of rod tacking to a minimum.
The prior art batch process provides a substantial amount of time in which the aluminum can oxidize, as when the cast ingot cools or is being reheated, when the rod fron the roll~ng mill cools or is being reheated ~or solutionizing, and when the solutionized rod from the reheating oven cools. I'h~
resu~t is that the rod becomes substantially oxidized, "hich mak~s it relatively hard for redrawing purposes, and which causes a rod to ha~e a relati~ely dull finish. ~rther, a ii33805 highly oxidized and hard rod is more difficult to draw and the dies used for drawing deteriorate rapidly. Thus, the separate steps require~ in the prior art batch process for forming 6201 Aluminum Alloy rod are expensive in that separate handling of the rod is required between and during each step, the product must be handled in a careful manner, and extra equipment must be available and maintained to handle this product.
An improved method for continuously casting and rolling h201 Aluminum Alloy was described in U.S. Patent No.
3,613,767. Briefly described, the invention of U.S. Patent ~o. 3,613,767 comprised a method of continuously manuacturing aluminum base alloy rod, such as 6201 Aluminum Alloy rod, without the necessity or reheating the ingot or the rod during the process. The bar emerging from a continuous castin(3 machine was passed through a rolling mill, a quench tubc, and then cooled in a continuous process. The heat of the cast bar emerging from the continuous casting machine was not dissipated and bar temperature was maintained in the solutionizing temperature range of the metal as a rod was passed to the rolling mill. The rod was hot worked in the rolling mill and quenched immediately as it emerged fro-n the rolling mill so that the time lapse from the point where the bar entered the rolling mill to where the rod was ~uenched to a temperature level below the crystallization temperature of the alloy metals was less than the time required for the alloy metals to precipitate to the grain houndarics of the metal.
After the rod was quenched it was at a temperature helow the temperature where immediate and substantial precipitation occurs. When the rod was subse~uently cold drawn into wire it 3~ had an unus~ally high tensile strength and a relatively high electrical conductivity, and an unusually bright appearance.
~hus, the major problems of separate han~lng betwccn cclch o the steps in the prior art process were e1l?ninate~ by the practice of the invention disclosed in U.S. Patent ~o.
3,613,7~7. ~owever, the solution to the pro~lems inherent in the prior art batch process ~or preparing ~01 Aluminum Alloy resulted in an aluminum alloy t-od, which due to the heat loss betwee~ the casting wheel of the continuous casting machinc 11338~S
and the point at which the bar entered the rolling mill, had large precipitates on the order of 20,000 angstrom units in size formed therein because of the relatively high temperature at which precipitation was occuring. Also the solution to the problems caused by batch preparation of 6201 Aluminum Alloy by the method of U.S. Patent No. 3,613,767 created an entirely new problem. In Column 5 beginning at line 3~ of Patent No.
3,613,767 the following statement is found:
"It has been found that the temperature and other conditions in the process can be varied within reasonable limits without detriment to the characteristics of the product. ~or instance, the temp~rature of the molt~!n metal in the pouring pot.and the metal bar extracted from the casting wheel appear to have no effect on the quality of the 6201 alloy rod as long as the temperature is not lowered below the solutionizing temperature."
While this statement may be true with respect to the alloy properties of 6201 it is incorrect with respect to the properties of the cast bar and the rod rolled from the cast ~ar. U,S. Patent No. 3,616,7h7 describes a method of continuously casting 6201 which requires that the cast bar exit the casting wheel at a temperature above the solutionizing temperature and remain above this tempercture until the cast bar enters the rolling mill where hot wc,rking and quenching subsequently occur. In order to meet this requirement the cast bar o~ U.S. Patent ~o. 3,613,767 m~st exit the casting wheel at a temperature substantially above the solutioizing temperature of the a~loy. To remove the cast bar from the casting wheel at the temperatures taught ~,y U.S.
Patent No. 6,613,767 the bar must ~e cooled in such a way that the bar does not become totally solid until it reaches a point on the casting wheel that molten metal cannot flow into, and fill, voids created in the bar by the shrin~age of the metal in the casting mold during so:lidification. If such voids are created on the exterior portions of the cast bar oxidat,ion will occur within the void and when the har is rolled o,cide inclusions will be trapped within the resul,tant rod caosinc~
the rod to b~come brittle an~ the points where the oxid~
inclusions occur thereby significantly decreasing the drawability of the rod. If solidification shrinkage voids occur in the interior of the rod where oxidation cannot occur such voids will caus internal microcracking which significantly affects the elongation of the rod thereby directly affecting the post cold working characteristics of the rod.
It has also been found that the solutionizing temperature of 6201 alloy varies according to the concentration of alloying elements present within the alloy in that the higher the concentration of alloying elements present the low~r the solutionizing temperature range of the alloy.
There~ore given the range of concentrations acceptable within 6201 alloy the solutionizing temperature may vary from about 850~F to a~70ut 114~ . Accordingly U.S. Patent No. 3,616,767 does not provide an acceptable method for continuously producing 6201 alloy rod having alloying element concentrations in the range which cause the alloy to solutionize at temperatures in the upper portion of the 620L
alloy solutionizing temperature range. Accordingly, there still remains significant improvements to he made in a process for continuously casting heat treatable aluminum alloy rod from alu~inum alloys such as 6201.
For the purpose of clarity, heat treatable aluminum alloys as used in this specification shall mean those a]uminum alloys which contain alloying ~lements which have a high solid solut7ility in aluminum at high temperatures and low s013d solubility in aluminum when cooled to room temperature. These 3~ alloys harden be precipitation of a second phase during heat treatment and the alloying ele~ents are kept ~n solution by rapid quenching from hiyh temporatures, For the purpose of clarity, wrought a:Luminum allo-~s as used in this specification shaLl mean those aluminum alLoys which contain alLoying eLements which have low solid solubility in aluminum at high temperatures as well as low temperatures. These alloys normally harden by work har<ienin~
which is a hardening mechanism which operates during cold ~133805 working of the alloy.
SUMMARY OF THE INVENTIO~
Thus, it is an object of this invention to provide an improved method for producing aluminum alloy products from heat treatable aluminum alloys.
Another object of this invention is to provide a method of continuously manufacturing a heat treatable aluminum alloy rod without the necessity of reheating an ingot or rod to produce a product having a hiqh tensile strength and high 10 conductivity characteristics.
Another object of this lnvention is to provide ar improved 6201 aluminum product and a method for forming such a product without the formation of large precipitated intermetallic particles in the grain structure.
Another object of this invention is to provide ar, ecomomical and expedient method ~or manufacturing 6201 al~lminum alloy rod.
Still another object of this invention is to provide a method for continuously manufacturing a heat treatable 6201 20 aluminum alloy rod from 6201 aluminum alloys having solutioniæing temperatures within the range of from about 8~0F to about 10B0F.
Yet another o~ject of this invention is to provi<~e a method for continuously casting and rolling a heat treata~le 6201 aluminum alloy rod wherein the cast bar is not sut,ject to solidification shrinkage.
Another object of this invention is to provide an improved 6201 heat treatable aluminum alloy product with a more uniform heat treatment along its entire length. ~ther 3~ obiects, features and advantages of the present invention will hecome apparent upon reading the following specifications when ta3~en in coniunction with ~he accompanying drawings.
~RIEF DFSCRIPTIO~ OF ~F _ AWI~GS
Fig. 1 is a schematic side elevationcll view of a casting machine, rolling mill, quenching tube, ancl coiler utilized in ~, the procedure herein set forth.
Fig. 2 is a ternary diagram which graphically represents the solubility of magnesium, silicon and the intermetallic compound magnesium silicide in aluminum at various temperatures.
Fig. 3 is a graphical representation of the effec~ of heat treating 6201 aluminum alloy by the present invention compared to prior art methods of preparing 6201 aluminum alloy.
DESC~IPTION OF THE PR~FE~RED EM~ODIMENT
Referring now in particular to the drawings, in which like numerals indicate li~e parts throughout the several vi~-~ws, Fig 1 shows a casting machine 10, a heater 11, a rolling mill 12, a quench tube assembly 13, and coiler 14. In summary, the process of the prescnt invention comprises pouring moltem metal from a furnace (not shown) into a casting wheel 10a of casting machine 1~. The molten metal is cooled and solidified in casting wheel 10a and extracted as a solid bar 15 at a temperature below 940~ and guided toward and through heater 11 wherein the solid bar 15 is continuously heated until the temperature O the bar is within the range of from about 850~F to about 1080F. The heated bar 15 is then guided toward and through rolling mill 12. The product is lengthened and reduced in its cross-sectional area within rolling mill 12, and emerges as a wrouyht rod 17. Pod 17 is passed through quench tube assembly 13 which includes first stage quench tube 18, pinch rollers 1~, second stage quench tu~e 20, pinch rollers 21, and rod conduit 22. The rod emerges from rod conduit 22 and is formed into coils b~ coiler 3~ 14. Pump 23 receives the quenching liquid from sump 24 and pressurizes first stage quench tube 18. ~he yuenching ~iquid is passed through quench tube 1~ in a direcrion of ~low which Is along the path of travel of rod 17 and is passed through a conduit system to cooling tower 26, where it is cooled ~nd recirculated back to sump 24. Pump 27 receives quenchi~g liquid from sump 2~ and pressurizes second ~stage ~uench tuhe 20. The ~uenching liquid of the second stage ~uench tuhe is passed through q~sench tube 20 in a counterflow relationship with the respect of the movement of the rod 17, and is ~assed through a conduit system to cooling tower 31 where it i~
cooled and recirculated back to sump 28. Thus, the quenching liquids are maintained at controlled temperatures during the quenching process.
In more detail, the molten metal process throu~sh the apparatus is a heat treatable aluminum alloy. If the product to be formed is to be 62~1 aluminum alloy, the ranges of silicon and magnesium contents are from about 0.50 to ahout 0.90 percent, and from about 0.60 to about 0.90 percent, respectively. The range of silicon and magnesium alloys can vary in this metal beyond the range for 6201 alloy to ~.3 to about 1.2 percent and to 0.3 to about 1.2 percent respectively, if desired. The metal in its ~olten state is poured through a fiberglass screen into a holding pot maintained at a temperature al:,ove 12~0F, usually at as~,out 1270DF. From a holding pot, the metal is poured into casting wheel lOa where it is cooled and solidified into a cast bar 15 at a rate at which inverse se~regation will be substantially minimized, for example at a rate of from about 24~F per second when casting a 3.3 square inch bar at a rate of 30 feet per minute to about 321? per second when casting a bar of equal cross-section at a casting rat:e of 40 feet per minute and approximately 50F per second when casting a bar of equal cross-section at a castiny rat:e of 50 feet per minute. The cast bar is stripped from casting wheel lOa at a temperature of from about 70~F to about 940F and passed to and through heater 11 wherein the temperal:ure of cast bar is incre,lsed to a point at which the alloying elements are solutionize(l.
~eater 1~ continuously supplies energy to t:he rod t~ler~s~y increasing the temperature of rod 15 to rom as`~out 5350F to about 108~F, usually to from about 95~. to about 1020DF and depending upon the alloy conposition to from as~out 1020F to about 1080~F. As the cast bar exits heater 15 it is ~3;sided toward and through rolling mill 12, the bar is ho~ ~orsned and coated with a soluble oil concentration maintained at 3bout 40 percent and at a temperature below 200~, usuA11~ at a~out 1~338~S
-- 1() --160F. ~olling mill 12 includes a plurality of roll stands which compress the cast bar alternatively from top to bottom and side to side, which functions to lengthen the cast bar and reduce the cross-sectional area of the cast bar, so that the cast bar is progressively fromed into redraw rod 17. The volume of the soluble oil concentration in rolling mill 12 is maintained at a level of about two-thirds the volume in a typical continuous casting system for EC rod. The temperature and volume of the coolant applied to the rod in the rolling mill are adjustable so that when the rod ~7 emerges from rolling mill 12, the temperature of the rod is at a level so that the rod is still within its hot forming temperature range, which is usually abovc 6~0F, so that the alloy metals have not precipitated from the aluminum. The low volume of coolant applied to the rod in the rolling mill requires a higher concentration of lubricant, approximately 40 per-cent solution as compared to approximately 10 percent for an EC rod system, and the flow is adjusted so that approximately equal flow of coolant is maintained at each rsll stand.
Fig. 2 is a Ternary dia~ram which graphically re~resents the solubility o~ magnesium, silicon and magnesium silicide in aluminum at various temperatures ranging from 440C or 852F
to 535~ or 995F.
Straight line 40 represfnts the increase in solut)ility of maynesium silicon and magnesium silicide in the 62~1 alloy system as temperature increases to approximately g95F. Point 42 on straight line 40 represents the amount of magnesium, solicon and magnesium silicide which is in solution in a continuously cast rod of 6201 aluminum alloy when the rod has been treated by the prior art method of heat treating continuously cast 6201 alloy. Point 43 represents the amount of magnesium, magnesium silicide and silicon which is retained ~n the 6201 alloy system in solution when a continuously cast rod of 62nl aluminum alloy is heat treated hy the presfnt invention. As can ~e seen from the diagram of Fig. 2, there is a ~2 percent increase in the amount o~ magnesium sllicide in solution in the 6201 alloy system when the alloy is continuously cast and rolled into a rod and is hf~at treatd - 11338~5 according to the present invent:ion during the continuouc casting and rollin~ operation.
~ n example of the improvc-d properties result from the increased amount of magnesium silicide in solution in the alloy matrix prior to aging and prcipitation follows. I~ cast bar was continuously cast usin~3 the prior art method for heat treating continuously cast 6201 aluminum alloy and the following results were obtained. ~ltimate tensile strength of the final wire was 45 700 PSI with an elongation of ~.3 percent and a conductivity of 52.5 percent IACS. After establishing the above properties as a base line, the bar temperature at a point between the casting machine and t:he entry of the bar into the rolling mill was raised from 900F
to 1020F by the method of the present invention. The ~)ar was then rolled into a rod and made into wire and the physical properties of the wire made from the bar treated according to the present invention were as follows:
~ltimate tensile strength - 50,800 PSI
Elongation - 7.9~
Conductivity - 52.5%
Fig. 3 is a graphical representation of propertie;
resulting from prior art heat treatment of continuously cast 6201 aluminum alloy rod and 62()1 alloy rod continuously cast and heat treated according to the present invention wherein curve 50 depicts the relationship between the conductivity and ultimate tencile strength of wire fabricated from 6201 aluminum alloy rod processed by prior art techni~ues an(~ c~rve 52 depicts the relationship between the conducti~ity an(3 ultimate tensile strength of wire fabricated from 62~1 aluminum alloy rod processed by the method of the present invention.
While this invention has bcen described in detail wit~, particular reference to preferfed embodiments thereof, it will be understood that variations and modifications can be effective within the spirit and scope of the invention as descrihed hereinbefore and as defined in the appended claims ,
.
6201 Aluminum Alloy is a high strength aluminum maq- !
nesium silicon alloy which in wire form and in the heat treated condition has a tensile strength of over 46,000 PSI, elongation greater than 3 percent, and an electrical conductivity greater . than 52.5 percent IACS. In the past, 6201 Aluminum Alloy redraw I
~ rod and similar aluminum alloy redraw rods have been manufactured -` for commercial use ~y a plurality of separate steps .which include ~ DC casting an aluminum in~ot reheating thc in~ot to about 700 L0 ~: to 850F, hot rolling the cast ingot to redraw rod and solution-izing the rod at a temperature of approximately 1000F and water quenching the rod. The rod is cold drawn to form wire, and the wire is artificially aged ~t tR~p~AtUres ~QtwQen 25~ a~d 450F. This proccdure is capable of producing wire having ..... ...tensile.strength and electrical conductivity characteristics which are sim~lar to or in excess of those for 6201 Aluminum. ?
While the foregoing procedure produces an acceptable product, such a ~atch process or non-continuous casting process, is ~apable of producing only a limite-3 amount of rod; that is, ~ the given size billet will produce on1y a corresponding mass of rod, and the lengths of separately produced rod must be welded together to form longer lengths of rod. When the billet is reheated and rolled to form rod, it is customary to crop tne leadtng end of the rod since it is of an inferior quality. Tl~us a su~stantial amount of waste is experienced in the formcr procedure. An e~ongated rod which comprises several lengths of batch produce~ products welded together will include poor g~ain ,, . _ . .. .. . .
~i33805 structure at the places where it is welded together, which affects tensile strength and conductivity. Furthermore, it is virt~ally impossible to create identical conditions in the reheating and rolling of different billets, and the lengths of rod welded together will usually have different grain characteristics.
In order to reheat the rod in this batch system, the rod must be carefully handled in order to achieve uniform heating and in order to produce a uniform product. For instance, the oven in which the rod is placed for solutionizing must ~reate relatively e~en heat distribution in order that the rod be uniformly heated. ~urthermore, the rod usually must be arranged so that there is enough circulation of air or gases n the oven between the coils to insure proper heat distribution. It is customary to place individual coils of ro~ on porta~le racks which space the coils from cach other for this purpose; however, the racks occupy space in the oven and reduce the volume of rod which can be heated. Whilo the purpose of reheating the rod is to solutionize the rod, it is desirable to keep the rod from reaching a temperature substantially higher than its solutionizing temperature since the overlapping portions of the rod in the coils in the rod tend to hecome tacked or welded together. This tacking together of the portions of the rod creates surface ~lemishes on the rod when pulled apart, and frequently the coils remain tacked together so that several coils of rod tend to pay out together. Thus even heat distribution within the solutionizing oven is a practical necessity so that the rod can be rapidly and uni~ormly solutionized to hold the hazard of rod tacking to a minimum.
The prior art batch process provides a substantial amount of time in which the aluminum can oxidize, as when the cast ingot cools or is being reheated, when the rod fron the roll~ng mill cools or is being reheated ~or solutionizing, and when the solutionized rod from the reheating oven cools. I'h~
resu~t is that the rod becomes substantially oxidized, "hich mak~s it relatively hard for redrawing purposes, and which causes a rod to ha~e a relati~ely dull finish. ~rther, a ii33805 highly oxidized and hard rod is more difficult to draw and the dies used for drawing deteriorate rapidly. Thus, the separate steps require~ in the prior art batch process for forming 6201 Aluminum Alloy rod are expensive in that separate handling of the rod is required between and during each step, the product must be handled in a careful manner, and extra equipment must be available and maintained to handle this product.
An improved method for continuously casting and rolling h201 Aluminum Alloy was described in U.S. Patent No.
3,613,767. Briefly described, the invention of U.S. Patent ~o. 3,613,767 comprised a method of continuously manuacturing aluminum base alloy rod, such as 6201 Aluminum Alloy rod, without the necessity or reheating the ingot or the rod during the process. The bar emerging from a continuous castin(3 machine was passed through a rolling mill, a quench tubc, and then cooled in a continuous process. The heat of the cast bar emerging from the continuous casting machine was not dissipated and bar temperature was maintained in the solutionizing temperature range of the metal as a rod was passed to the rolling mill. The rod was hot worked in the rolling mill and quenched immediately as it emerged fro-n the rolling mill so that the time lapse from the point where the bar entered the rolling mill to where the rod was ~uenched to a temperature level below the crystallization temperature of the alloy metals was less than the time required for the alloy metals to precipitate to the grain houndarics of the metal.
After the rod was quenched it was at a temperature helow the temperature where immediate and substantial precipitation occurs. When the rod was subse~uently cold drawn into wire it 3~ had an unus~ally high tensile strength and a relatively high electrical conductivity, and an unusually bright appearance.
~hus, the major problems of separate han~lng betwccn cclch o the steps in the prior art process were e1l?ninate~ by the practice of the invention disclosed in U.S. Patent ~o.
3,613,7~7. ~owever, the solution to the pro~lems inherent in the prior art batch process ~or preparing ~01 Aluminum Alloy resulted in an aluminum alloy t-od, which due to the heat loss betwee~ the casting wheel of the continuous casting machinc 11338~S
and the point at which the bar entered the rolling mill, had large precipitates on the order of 20,000 angstrom units in size formed therein because of the relatively high temperature at which precipitation was occuring. Also the solution to the problems caused by batch preparation of 6201 Aluminum Alloy by the method of U.S. Patent No. 3,613,767 created an entirely new problem. In Column 5 beginning at line 3~ of Patent No.
3,613,767 the following statement is found:
"It has been found that the temperature and other conditions in the process can be varied within reasonable limits without detriment to the characteristics of the product. ~or instance, the temp~rature of the molt~!n metal in the pouring pot.and the metal bar extracted from the casting wheel appear to have no effect on the quality of the 6201 alloy rod as long as the temperature is not lowered below the solutionizing temperature."
While this statement may be true with respect to the alloy properties of 6201 it is incorrect with respect to the properties of the cast bar and the rod rolled from the cast ~ar. U,S. Patent No. 3,616,7h7 describes a method of continuously casting 6201 which requires that the cast bar exit the casting wheel at a temperature above the solutionizing temperature and remain above this tempercture until the cast bar enters the rolling mill where hot wc,rking and quenching subsequently occur. In order to meet this requirement the cast bar o~ U.S. Patent ~o. 3,613,767 m~st exit the casting wheel at a temperature substantially above the solutioizing temperature of the a~loy. To remove the cast bar from the casting wheel at the temperatures taught ~,y U.S.
Patent No. 6,613,767 the bar must ~e cooled in such a way that the bar does not become totally solid until it reaches a point on the casting wheel that molten metal cannot flow into, and fill, voids created in the bar by the shrin~age of the metal in the casting mold during so:lidification. If such voids are created on the exterior portions of the cast bar oxidat,ion will occur within the void and when the har is rolled o,cide inclusions will be trapped within the resul,tant rod caosinc~
the rod to b~come brittle an~ the points where the oxid~
inclusions occur thereby significantly decreasing the drawability of the rod. If solidification shrinkage voids occur in the interior of the rod where oxidation cannot occur such voids will caus internal microcracking which significantly affects the elongation of the rod thereby directly affecting the post cold working characteristics of the rod.
It has also been found that the solutionizing temperature of 6201 alloy varies according to the concentration of alloying elements present within the alloy in that the higher the concentration of alloying elements present the low~r the solutionizing temperature range of the alloy.
There~ore given the range of concentrations acceptable within 6201 alloy the solutionizing temperature may vary from about 850~F to a~70ut 114~ . Accordingly U.S. Patent No. 3,616,767 does not provide an acceptable method for continuously producing 6201 alloy rod having alloying element concentrations in the range which cause the alloy to solutionize at temperatures in the upper portion of the 620L
alloy solutionizing temperature range. Accordingly, there still remains significant improvements to he made in a process for continuously casting heat treatable aluminum alloy rod from alu~inum alloys such as 6201.
For the purpose of clarity, heat treatable aluminum alloys as used in this specification shall mean those a]uminum alloys which contain alloying ~lements which have a high solid solut7ility in aluminum at high temperatures and low s013d solubility in aluminum when cooled to room temperature. These 3~ alloys harden be precipitation of a second phase during heat treatment and the alloying ele~ents are kept ~n solution by rapid quenching from hiyh temporatures, For the purpose of clarity, wrought a:Luminum allo-~s as used in this specification shaLl mean those aluminum alLoys which contain alLoying eLements which have low solid solubility in aluminum at high temperatures as well as low temperatures. These alloys normally harden by work har<ienin~
which is a hardening mechanism which operates during cold ~133805 working of the alloy.
SUMMARY OF THE INVENTIO~
Thus, it is an object of this invention to provide an improved method for producing aluminum alloy products from heat treatable aluminum alloys.
Another object of this invention is to provide a method of continuously manufacturing a heat treatable aluminum alloy rod without the necessity of reheating an ingot or rod to produce a product having a hiqh tensile strength and high 10 conductivity characteristics.
Another object of this lnvention is to provide ar improved 6201 aluminum product and a method for forming such a product without the formation of large precipitated intermetallic particles in the grain structure.
Another object of this invention is to provide ar, ecomomical and expedient method ~or manufacturing 6201 al~lminum alloy rod.
Still another object of this invention is to provide a method for continuously manufacturing a heat treatable 6201 20 aluminum alloy rod from 6201 aluminum alloys having solutioniæing temperatures within the range of from about 8~0F to about 10B0F.
Yet another o~ject of this invention is to provi<~e a method for continuously casting and rolling a heat treata~le 6201 aluminum alloy rod wherein the cast bar is not sut,ject to solidification shrinkage.
Another object of this invention is to provide an improved 6201 heat treatable aluminum alloy product with a more uniform heat treatment along its entire length. ~ther 3~ obiects, features and advantages of the present invention will hecome apparent upon reading the following specifications when ta3~en in coniunction with ~he accompanying drawings.
~RIEF DFSCRIPTIO~ OF ~F _ AWI~GS
Fig. 1 is a schematic side elevationcll view of a casting machine, rolling mill, quenching tube, ancl coiler utilized in ~, the procedure herein set forth.
Fig. 2 is a ternary diagram which graphically represents the solubility of magnesium, silicon and the intermetallic compound magnesium silicide in aluminum at various temperatures.
Fig. 3 is a graphical representation of the effec~ of heat treating 6201 aluminum alloy by the present invention compared to prior art methods of preparing 6201 aluminum alloy.
DESC~IPTION OF THE PR~FE~RED EM~ODIMENT
Referring now in particular to the drawings, in which like numerals indicate li~e parts throughout the several vi~-~ws, Fig 1 shows a casting machine 10, a heater 11, a rolling mill 12, a quench tube assembly 13, and coiler 14. In summary, the process of the prescnt invention comprises pouring moltem metal from a furnace (not shown) into a casting wheel 10a of casting machine 1~. The molten metal is cooled and solidified in casting wheel 10a and extracted as a solid bar 15 at a temperature below 940~ and guided toward and through heater 11 wherein the solid bar 15 is continuously heated until the temperature O the bar is within the range of from about 850~F to about 1080F. The heated bar 15 is then guided toward and through rolling mill 12. The product is lengthened and reduced in its cross-sectional area within rolling mill 12, and emerges as a wrouyht rod 17. Pod 17 is passed through quench tube assembly 13 which includes first stage quench tube 18, pinch rollers 1~, second stage quench tu~e 20, pinch rollers 21, and rod conduit 22. The rod emerges from rod conduit 22 and is formed into coils b~ coiler 3~ 14. Pump 23 receives the quenching liquid from sump 24 and pressurizes first stage quench tube 18. ~he yuenching ~iquid is passed through quench tube 1~ in a direcrion of ~low which Is along the path of travel of rod 17 and is passed through a conduit system to cooling tower 26, where it is cooled ~nd recirculated back to sump 24. Pump 27 receives quenchi~g liquid from sump 2~ and pressurizes second ~stage ~uench tuhe 20. The ~uenching liquid of the second stage ~uench tuhe is passed through q~sench tube 20 in a counterflow relationship with the respect of the movement of the rod 17, and is ~assed through a conduit system to cooling tower 31 where it i~
cooled and recirculated back to sump 28. Thus, the quenching liquids are maintained at controlled temperatures during the quenching process.
In more detail, the molten metal process throu~sh the apparatus is a heat treatable aluminum alloy. If the product to be formed is to be 62~1 aluminum alloy, the ranges of silicon and magnesium contents are from about 0.50 to ahout 0.90 percent, and from about 0.60 to about 0.90 percent, respectively. The range of silicon and magnesium alloys can vary in this metal beyond the range for 6201 alloy to ~.3 to about 1.2 percent and to 0.3 to about 1.2 percent respectively, if desired. The metal in its ~olten state is poured through a fiberglass screen into a holding pot maintained at a temperature al:,ove 12~0F, usually at as~,out 1270DF. From a holding pot, the metal is poured into casting wheel lOa where it is cooled and solidified into a cast bar 15 at a rate at which inverse se~regation will be substantially minimized, for example at a rate of from about 24~F per second when casting a 3.3 square inch bar at a rate of 30 feet per minute to about 321? per second when casting a bar of equal cross-section at a casting rat:e of 40 feet per minute and approximately 50F per second when casting a bar of equal cross-section at a castiny rat:e of 50 feet per minute. The cast bar is stripped from casting wheel lOa at a temperature of from about 70~F to about 940F and passed to and through heater 11 wherein the temperal:ure of cast bar is incre,lsed to a point at which the alloying elements are solutionize(l.
~eater 1~ continuously supplies energy to t:he rod t~ler~s~y increasing the temperature of rod 15 to rom as`~out 5350F to about 108~F, usually to from about 95~. to about 1020DF and depending upon the alloy conposition to from as~out 1020F to about 1080~F. As the cast bar exits heater 15 it is ~3;sided toward and through rolling mill 12, the bar is ho~ ~orsned and coated with a soluble oil concentration maintained at 3bout 40 percent and at a temperature below 200~, usuA11~ at a~out 1~338~S
-- 1() --160F. ~olling mill 12 includes a plurality of roll stands which compress the cast bar alternatively from top to bottom and side to side, which functions to lengthen the cast bar and reduce the cross-sectional area of the cast bar, so that the cast bar is progressively fromed into redraw rod 17. The volume of the soluble oil concentration in rolling mill 12 is maintained at a level of about two-thirds the volume in a typical continuous casting system for EC rod. The temperature and volume of the coolant applied to the rod in the rolling mill are adjustable so that when the rod ~7 emerges from rolling mill 12, the temperature of the rod is at a level so that the rod is still within its hot forming temperature range, which is usually abovc 6~0F, so that the alloy metals have not precipitated from the aluminum. The low volume of coolant applied to the rod in the rolling mill requires a higher concentration of lubricant, approximately 40 per-cent solution as compared to approximately 10 percent for an EC rod system, and the flow is adjusted so that approximately equal flow of coolant is maintained at each rsll stand.
Fig. 2 is a Ternary dia~ram which graphically re~resents the solubility o~ magnesium, silicon and magnesium silicide in aluminum at various temperatures ranging from 440C or 852F
to 535~ or 995F.
Straight line 40 represfnts the increase in solut)ility of maynesium silicon and magnesium silicide in the 62~1 alloy system as temperature increases to approximately g95F. Point 42 on straight line 40 represents the amount of magnesium, solicon and magnesium silicide which is in solution in a continuously cast rod of 6201 aluminum alloy when the rod has been treated by the prior art method of heat treating continuously cast 6201 alloy. Point 43 represents the amount of magnesium, magnesium silicide and silicon which is retained ~n the 6201 alloy system in solution when a continuously cast rod of 62nl aluminum alloy is heat treated hy the presfnt invention. As can ~e seen from the diagram of Fig. 2, there is a ~2 percent increase in the amount o~ magnesium sllicide in solution in the 6201 alloy system when the alloy is continuously cast and rolled into a rod and is hf~at treatd - 11338~5 according to the present invent:ion during the continuouc casting and rollin~ operation.
~ n example of the improvc-d properties result from the increased amount of magnesium silicide in solution in the alloy matrix prior to aging and prcipitation follows. I~ cast bar was continuously cast usin~3 the prior art method for heat treating continuously cast 6201 aluminum alloy and the following results were obtained. ~ltimate tensile strength of the final wire was 45 700 PSI with an elongation of ~.3 percent and a conductivity of 52.5 percent IACS. After establishing the above properties as a base line, the bar temperature at a point between the casting machine and t:he entry of the bar into the rolling mill was raised from 900F
to 1020F by the method of the present invention. The ~)ar was then rolled into a rod and made into wire and the physical properties of the wire made from the bar treated according to the present invention were as follows:
~ltimate tensile strength - 50,800 PSI
Elongation - 7.9~
Conductivity - 52.5%
Fig. 3 is a graphical representation of propertie;
resulting from prior art heat treatment of continuously cast 6201 aluminum alloy rod and 62()1 alloy rod continuously cast and heat treated according to the present invention wherein curve 50 depicts the relationship between the conductivity and ultimate tencile strength of wire fabricated from 6201 aluminum alloy rod processed by prior art techni~ues an(~ c~rve 52 depicts the relationship between the conducti~ity an(3 ultimate tensile strength of wire fabricated from 62~1 aluminum alloy rod processed by the method of the present invention.
While this invention has bcen described in detail wit~, particular reference to preferfed embodiments thereof, it will be understood that variations and modifications can be effective within the spirit and scope of the invention as descrihed hereinbefore and as defined in the appended claims ,
Claims (17)
1. A method of manufacturing a heat treatable hot formed aluminum base alloy product having a substantially extended shelf life comprising: casting a molten aluminum base alloy metal within a continuous casting mold; cooling said molten aluminum base alloy metal during casting to a temperature below 940°F, at a rate at which inverse segregation will be substan-tially minimized, to form a cast bar; continuously removing said cast bar from said continuous casting mold and heating said cast bar, prior to the initiation of the step of hot forming the cast bar, to a temperature above the temperature at which the alloying metals would substantially precipitate; initiating the step of hot forming the cast bar while the cast bar is at a temperature within the hot forming temperature range of the metal and which is a solutionizing temperature of the metal, continuing the not forming process while maintaining the temperature of the cast bar within the hot forming temperature range, reducing the temperature of the bar after the step of hot forming the cast bar, and controlling the temperature of the bar during the not forming step and the temperature reducing step so as to reduce the temperature of the bar from the solutionizing temperature to a temperature at which no substantial immediate precipitation occurs within the time interval before which substantial precipitation occurs and controlling the solution heat treatment temperature of the bar within the solutionizing temperature range and controlling the time the bar' is within the solutionizing temperature range such that said product has controlled precipitation during natural aging.
2. A method of manufacturing an aluminum base alloy rod having a substantially extended shelf life containing from about 0.3 to about 1.2 weight percent silicon, about 0.3 to about 1.2 weight percent magnessium and the remainder essentially aluminum comprising the steps of:
(a) pouring a molten aluminum base alloy contain-ing from about 0.3 to about 1.2 weight percent silicon, about 0.3 to about 1.2 weight percent magnesium and the remainder essen-tially aluminum into the casting groove of a continuous casting wheel at a temperature above the melting point of the aluminum base alloy;
(b) cooling the molten aluminum base alloy in the casting groove at a rate at which inverse segregation will be substantially minimized to form a cast bar;
(c) removing the cast bar from the casting groove at a temperature below 940°F;
(d) passing the cast bar through a heater and raising the temperature of the cast bar to a temperature above the temperature at which the alloying metals would substantially precipitate;
(e) continuously hot forming the cast aluminum base metal to form a rod at a temperature above the temperature at which the alloying metals precipitate;
(f) continuously quenching the rod to a tempera-ture level below the temperature at which immediate substantial precipatation of alloying metals occur, and completing the cooling of the cast metal from the beginning of the hot forming step to the end of the quenching step within a time interval before which substantial precipitation of the alloying metals occur; and (g) controlling during steps (c), (d), (e) and (f) the solution heat treatment temperature of the bar within the solutionizing temperature range and controlling during said steps the time the bar is within the solutionizing temperature range such that said product has controlled precipitation during natural aging.
(a) pouring a molten aluminum base alloy contain-ing from about 0.3 to about 1.2 weight percent silicon, about 0.3 to about 1.2 weight percent magnesium and the remainder essen-tially aluminum into the casting groove of a continuous casting wheel at a temperature above the melting point of the aluminum base alloy;
(b) cooling the molten aluminum base alloy in the casting groove at a rate at which inverse segregation will be substantially minimized to form a cast bar;
(c) removing the cast bar from the casting groove at a temperature below 940°F;
(d) passing the cast bar through a heater and raising the temperature of the cast bar to a temperature above the temperature at which the alloying metals would substantially precipitate;
(e) continuously hot forming the cast aluminum base metal to form a rod at a temperature above the temperature at which the alloying metals precipitate;
(f) continuously quenching the rod to a tempera-ture level below the temperature at which immediate substantial precipatation of alloying metals occur, and completing the cooling of the cast metal from the beginning of the hot forming step to the end of the quenching step within a time interval before which substantial precipitation of the alloying metals occur; and (g) controlling during steps (c), (d), (e) and (f) the solution heat treatment temperature of the bar within the solutionizing temperature range and controlling during said steps the time the bar is within the solutionizing temperature range such that said product has controlled precipitation during natural aging.
3. The method of Claim 2 wherein the molten aluminum base alloy is cooled to a temperature of from about 700°F to about 940°F in the casting groove.
4. The method of Claim 2 wherein the temperature of the cast bar after passing through the heater is from about 850°F
to about 1080°F.
to about 1080°F.
5. The method of Claim 2 wherein the temperature of the cast bar entering the hot forming step is from about 850°F to about 1080°F.
6. The method of Claim 3 wherein the step of contin-uously hot forming the cast metal to form a rod at a temperature above the temperature level at which the alloying metals precipi-tate comprises controlling the temperature of the bar during hot rolling the aluminum alloy bar by applying a soluble oil to the bar as it is rolled, said soluble oil being at a temperature of less than 200°F.
7. The method of Claim 3 wherein the step of continu-ously quenching the rod to a temperature below the temperature level at which immediate substantial precipitation of the alloy-ing metals occur, and completing the cooling of the alloyed aluminum metal from the beginning of the hot forming step to the end of the quenching step within the time interval before which any substantial precipitation of the alloying metals occur comprises: quenching the hot rolled rod immediately after it exits the hot rolling mill to a temperature of less than 400°F, the time interval between entrance into the hot rolling mill and the completion of the quench to a temperature of less than 400°F
being between 4 and 30 seconds.
being between 4 and 30 seconds.
8. The method of Claim 2 wherein the temperature of the cast bar after passing through the heater is from about 850°F
to about 950°F.
to about 950°F.
9. The method of Claim 2 wherein the temperature of the cast bar after passing through the heater is from about 950°F
to about 1020°F.
to about 1020°F.
10. The method of Claim 2 wherein the temperature of the cast bar after passing through the heater is from about 1020°F to about 1080°F.
11. The method of Claim 2 wherein the temperature of the cast bar entering the hot forming step is from about 850°F to about 950°F.
12. The method of Claim 2 wherein the temperature of the cast bar entering the hot forming step is from about 950°F to about 1020°F.
13. The method of Claim 2 wherein the temperature of the cast bar entering the hot forming step is from about 1020°F
to about 1080°F.
to about 1080°F.
14. The method according to Claim 2 further including the step of drawing the rod to wire, said wire having a minimum tensile strength of 50,800 p.s.i., a minimum elongation of 7.9%
and a minimum electrical conductivity of 52.5% I.A.C.S.
and a minimum electrical conductivity of 52.5% I.A.C.S.
15. The new use of the known state of the art casting device used in continuous casting of the type comprising the steps of a) pouring a molten aluminum base alloy into the casting groove of a continuous casting wheel at a temperature above the melting point of the aluminum base alloy;
b) cooling the molten aluminum base alloy in the casting groove to form a cast bar;
c) removing the cast bar from the casting groove;
d) continuously hot forming the cast aluminum base metal to form a rod; and e) continuously forming said rod into coils;
wherein the new process is characterized in that:
f) in step a) the aluminum alloy contains from about 0.3 to about 1.2 weight percent silicon, about 0.3 to about 1.2 weight percent magnesium and the remainder essentially alumi-num; step b) is performed at a rate at which inverse segregation will be substantially minimized; said step c) is performed at a temperature below 940°F; the cast bar prior to hot forming is passed through a heater and the temperature thereof raised above ?e temperature at which the alloying metals would substantially precipitate; step d) is performed at a temperature above which the alloying metals precipitate; prior to step e) said rod is continuously quenched to a temperature level below the temper-ature at which immediate substantial precipitation of alloying metals occur, the cooling of the cast metal from the beginning of the hot forming step to the end of the quenching step is com-pleted within a time interval before which substantial precipita-tion of the alloying metals occur; and the solution heat treatment temperature of the bar is controlled during steps c) through d) within the solutionizing temperature range and during said steps the time the bar is within the solutionizing temperature range is controlled such that said final product has controlled precipitation during natural aging.
b) cooling the molten aluminum base alloy in the casting groove to form a cast bar;
c) removing the cast bar from the casting groove;
d) continuously hot forming the cast aluminum base metal to form a rod; and e) continuously forming said rod into coils;
wherein the new process is characterized in that:
f) in step a) the aluminum alloy contains from about 0.3 to about 1.2 weight percent silicon, about 0.3 to about 1.2 weight percent magnesium and the remainder essentially alumi-num; step b) is performed at a rate at which inverse segregation will be substantially minimized; said step c) is performed at a temperature below 940°F; the cast bar prior to hot forming is passed through a heater and the temperature thereof raised above ?e temperature at which the alloying metals would substantially precipitate; step d) is performed at a temperature above which the alloying metals precipitate; prior to step e) said rod is continuously quenched to a temperature level below the temper-ature at which immediate substantial precipitation of alloying metals occur, the cooling of the cast metal from the beginning of the hot forming step to the end of the quenching step is com-pleted within a time interval before which substantial precipita-tion of the alloying metals occur; and the solution heat treatment temperature of the bar is controlled during steps c) through d) within the solutionizing temperature range and during said steps the time the bar is within the solutionizing temperature range is controlled such that said final product has controlled precipitation during natural aging.
16. The method of Claim 2 wherein the aluminum alloy contains from about 0.5 to about 0.9 weight percent silicon and from about 0.6 to about 0.9 weight percent magnesium.
17. The method of Claim 15 wherein the aluminum base alloy contains from about 0.5 to about 0.9 weight percent silicon and from about 0.6 to about 0.9 weight percent magnesium.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US97419278A | 1978-12-26 | 1978-12-26 | |
| US974,192 | 1978-12-26 |
Publications (1)
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|---|---|
| CA1133805A true CA1133805A (en) | 1982-10-19 |
Family
ID=25521721
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA342,603A Expired CA1133805A (en) | 1978-12-26 | 1979-12-21 | Method for solution heat treatment of 6201 aluminum alloy |
Country Status (20)
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| JP (1) | JPS55119141A (en) |
| KR (1) | KR830001394A (en) |
| AT (1) | AT371843B (en) |
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| BE (1) | BE876214A (en) |
| BR (1) | BR7908465A (en) |
| CA (1) | CA1133805A (en) |
| CH (1) | CH651323A5 (en) |
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| NO (1) | NO794091L (en) |
| SE (1) | SE7910553L (en) |
| ZA (1) | ZA796999B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| LU83249A1 (en) * | 1981-03-23 | 1983-02-22 | Huwaert Leo Cloostermans | PROCESS FOR MANUFACTURING ALUMINUM MACHINE WIRE |
| CN105821352A (en) * | 2016-04-17 | 2016-08-03 | 广东工业大学 | Aluminum product stirring friction weld joint and base metal strength uniformity improvement process method |
| CN107916336A (en) * | 2017-12-14 | 2018-04-17 | 宁夏太阳镁业有限公司 | A kind of magnesium alloy refining copple |
| CN114769542B (en) * | 2022-03-18 | 2024-03-15 | 云南云铝泽鑫铝业有限公司 | Casting process for bar production of 6-series aluminum-magnesium-silicon alloy |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3613767A (en) * | 1969-05-13 | 1971-10-19 | Southwire Co | Continuous casting and rolling of 6201 aluminum alloy |
| DE2602339C2 (en) * | 1975-01-24 | 1985-11-14 | Southwire Co., Carrollton, Ga. | Process for the continuous casting of an aluminum alloy |
-
1979
- 1979-04-27 AU AU46560/79A patent/AU531337B2/en not_active Ceased
- 1979-05-03 FI FI791423A patent/FI65030C/en not_active IP Right Cessation
- 1979-05-11 BE BE0/195129A patent/BE876214A/en not_active IP Right Cessation
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- 1979-12-14 NO NO794091A patent/NO794091L/en unknown
- 1979-12-19 GB GB7943706A patent/GB2046784B/en not_active Expired
- 1979-12-20 FR FR7931279A patent/FR2445389A1/en active Granted
- 1979-12-20 SE SE7910553A patent/SE7910553L/en unknown
- 1979-12-21 IN IN932/DEL/79A patent/IN153512B/en unknown
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- 1979-12-21 CA CA342,603A patent/CA1133805A/en not_active Expired
- 1979-12-26 KR KR1019790004612A patent/KR830001394A/en unknown
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- 1979-12-26 NL NL7909310A patent/NL7909310A/en not_active Application Discontinuation
- 1979-12-27 CH CH11474/79A patent/CH651323A5/en not_active IP Right Cessation
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| ES481719A1 (en) | 1980-03-01 |
| MX5801E (en) | 1984-07-25 |
| CH651323A5 (en) | 1985-09-13 |
| SE7910553A0 (en) | 1980-01-27 |
| ZA796999B (en) | 1981-01-28 |
| NO794091L (en) | 1980-06-27 |
| FR2445389A1 (en) | 1980-07-25 |
| GB2046784A (en) | 1980-11-19 |
| AT371843B (en) | 1983-08-10 |
| AU531337B2 (en) | 1983-08-18 |
| SE7910553L (en) | 1980-01-27 |
| IN153512B (en) | 1984-07-21 |
| FI65030B (en) | 1983-11-30 |
| IT7951176A0 (en) | 1979-12-21 |
| GB2046784B (en) | 1983-08-03 |
| KR830001394A (en) | 1983-04-30 |
| JPS55119141A (en) | 1980-09-12 |
| BE876214A (en) | 1979-09-03 |
| IT1164818B (en) | 1987-04-15 |
| FI65030C (en) | 1984-03-12 |
| AU4656079A (en) | 1980-07-03 |
| NL7909310A (en) | 1980-06-30 |
| FR2445389B1 (en) | 1984-10-26 |
| BR7908465A (en) | 1980-07-22 |
| DE2951911A1 (en) | 1980-07-03 |
| FI791423A (en) | 1980-06-27 |
| ATA815579A (en) | 1982-12-15 |
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