HUE027293T2 - Ötvözetek belsõ védõréteggel és forrasztott perturbátorral ellátott hõcserélõ csövekhez - Google Patents

Description

ALLOYS FOR ,¾ HEAT EXCHANGER TORA HAVI HQ Ah IddwR PROTECT! RE CLAODIdG AHO

BRAZED TORBULATQR

Field of the invention

The savent ion rebates to the field of bracing sheets: for aluminier alloys heat .exchanger tabeeu pa r t :t oulu r: 1 y those used for cooling or optimising engine efficiency., hers ting· or air condif honing of the gar songer compas fcraent.

This is particulariy applicable to hsat. exchanger tubes subject: to a severely .corrosive environment such as charged air cooler tushes; through, which exhaxret: gas exrouiation takes place, and usually presided with a turbo.! a tor desi unod to: improve heat or ana ago by increasing the exsnntge -orface ares and disturbing internal fluid circulation.

Aluminium alloys· are used for the fabrication of post aatoçiobile heat exchangers due to their .Low density which enables weight stir ing, particularly compared with copper alleys, while allowing good thermal conduct ion, ease of use sod good, resistance to corrosion.

Ail a 1 uisinium. alloys referred to in the: following are designated "using the désignât lens defined by the A1 ach.nium. Association in the, reguiariy' pubi fshed, Regi ehret ibn Record Rexries, xuiiess mentioned otherwise,

Exchangers: comprise tubes fett: the· circulation of internal fluid and fins or separators, and possibly' a turbulator to ifitrsase heat transfer between the interna! fluid anti the external fluid and era fabricated either fev' mechanical .assembly or by bracing.

In the casa? of Charged Alt' Coo ! era, knows to those skilled in the art under the texts OAC, the noma! configura ti on is as follows.: the tube: made from: a core sheet (usually called the tube strip) usually an: AAixrr: aiiariainai alloy, is cladded on its external and internal faces with an alloy called the braning alloy, usually an nAitex aeri.es. This has the advantage of melting at a temperature 'below the core melting temperature and, through application of a thermal brae lag gyeié, can create a bond •between two materials to be assembled, in other words braced, or possibly to bond the robe strip onto itself so as to close the tubs by brazing, the alternative being welding.

This: oonfi.guration is shown in figure 1, the core of the fobs strip befog referenced 2 and .Its internal and external bracing alloy clads being ref eretursd 1, The separators placed between the different tube rows ars composed of an un-" eladd ed At ixxx alloy. Similarly, the turbulatore tea:: ári: Inserted into ebe tubes are also: eoíaposed of un--cladded AAoxxa alloy, Inserts are brased on the tabes· by tee áxxx 0. Ladding of the ersernai face of the tube, The: tu:d:A:lasors ate fcrasea 1:.rï the t ebes by the ixxx cladding of the i ns.I oe face cd the tabs:. The: hAdxsx alleys: used for the separators and terbalators may or may not be identical. The Addxxs alloy used for the tube core is usually a so- called "long--life" ai icy, in otite r words it has good resistance to ex ce mal sa.f j.ee sorros i on.

Figaro 2 a hows a drawing of snob a turbulator tobe., tbe tube being referenced I, the· turbo!abet as 3 -and the braxing alloy clads· as 2. an example is: given fn patent appi 1 cat.foe Eh 0383237 hi by dlhou hadfator

Co, Ltd,

Cn treed J.y, there are some eng Lee ties igas in which exbaast gase.s are reiniectxKi into the charged air cooler to be ssixed with clean air arts returned, to the inlet, with the end purpose of reducing polluting1 ermiss ions; of rah it: les, I:g tb is configuration,. exhaust gases that could condense- car: generate a particularly severe corrosive environment in the cooler, characterised particularly by a low pb tthat can be significantly lower than. 3) , i:0: the case of a tube configuration according to the prior art as described above:, a signifleant diffusion of ailicon contained in the hA4:tsii alloy cladding' to the core alloy forming the: core: of the tube: oecura during the brazing operation, thereby degrading its corrosion res : stance:, A solution known to those skilled in the art consists of inserting an del xxx or hAlxxs alloy intermediate cladding between, the tube extra alloc·· and. its internal At··';xxx bracing alloy cladding during co-roll,ing.

Such a coni.ignration is represented in figure 3, the. tube itéra being referenced 3, the: AA4xxx alloy external cladding .being referenced 1, the Internal cladding also an At4xxx alloy being referenced 1, and the AA ; xxx or AA'íxxx alloy inferdediate cladding being referenced 3.

Such cladding acts by reducing the so ·· tut : on of silicon from the internal cl;nidind to the tube Cote during· bracing, thus improving its: cos rosion resistance. A sacrificiai alley, typically in the AAlxxx: series?·, may also be used S:S the Intermediate cladding alloy. 'these Fmaiti-ud adding" sheets a·:e known to those skilled in the art and are disclosed in particular i:n applications JE 20(13027166 A by habe Steel Ltd. Shirt ko dices, 02 2000224851 A bp Shinto Alcoa lose Klzai KK, rn 2000/044500 A2 and WÖ 2000/142651 A3: by Alcoa Inc, WO 2007/042206 A1 by Geras Aluarlnium Walxprodukte GmM', OS 2010/01((32:72 All by Ho va I is, etc. the use of this type of "moili---cladded"' sheers in a charged air· cooler through which exhanst curs passes is disclosed in ape lisa ·: ion WO 2000/06.2855 by (iodine dig Co,

Another solution disclosed in the applications EP 17 62819 A1 and US 200770051503 AI by Eehr America Inc,, consists of favouring: the creation or a "brown band" baown to those skilled in the art, between •the AAoirxx alley cere et the carbuiator and its cladding composed of an AA/xxx alloy {typically AAFOio/!, daring the cannent ionel-dyos brating inside the tube, fbe tube Is also typically an AAdxxx alloy clad with AAixxx el; both sides. In a buch preferred embodiment , the tube and the turbulatbr ate act: sally composed of t he sa re mater lal.

However, ad:, though such COnfi garat ions car: slightly· Improve the resistance of tile tube to corrosion, they may be insur i loi ent under particular ly sesrera load bondit: ions, which is the case lot heat exchangers subject to recirculation ·: :: exhaust gases, characterised part ion le ri y by a lose pH,

Other solutions consist: in applying: a so · 1 ace treatment after Praxing to isrprova the internal corrosion ret : s tanoe of the tube. This; is the case of the solution disclosed in appl icat: ion ER 2916525 Ai by vs ; ;r:.· Systèmes ilternigues, that recommends &' coating based on resins. Another example bi a surface treatment, in this case an eAeotg:o-o:e;ramic deposit:, is give:;: in application WO 2(513/05.0664, Application EE 2536023 by Faheo Systèmes Thormigues mentions the possibility of hoehmiting the entire exchanger·. Finally, the appl ioatioo EP 1506131 A 2 by International 1 ruck discloses a solution consisting of applying a metal surisse treatment based on hi or Co on the inside face of the tube arms on the turbuiator.

Finally, other solutions lie In thé use /,1 a ooiabinalu on of different materials, part icalariy alusuinium and stainless steel, Appl load: ion WO 2936/605576 by Beht OmbH & Go, thus :: : .:7 ms the use of stainless steel for the ttuituietor·, the tube being in aluminium, while application ΕΡ13ΐ)612:? by Internat tonal Truck proposes an . a lend ni:urn tube with si kir: le;:·:;, s tse 3. olad on the internai face, still with a stain less steel tu rbul a tor ,

However, such options so« too expensive to provide a design. ttot is entirely satisfactory industrially. fits invention is aimed at optimising the choice of materials or aluminium alloys bxaxinq sheets designed ton production· of exchanger tubes with tit a red t at toi.·;: tot to improve tâtait per ::or nance in a aeoero corrosive environment like: that, created i::·y recirculation of automobile vet: cd « exhaust gaset;, without noticeably increasing the quantity of .materials used, dimeneions; dt weight, and tot which manufacturing conditions from erasing sheets are at least eqaivalaot to so id tiens tel: the prior art . in to ms of ease of use and cos;·,

Purpose of the invention

The purpose ci the ; nveatton is an assembly of two braainy sheets,; the first being composed of an Aítlxxx alloy clad 0:0 one face with an Ahlxxx alloy, arid the second sheet being composed of an AA3xxx aluminium alloy clad on botit faces with an AAlxxx alloy, the two sheets beidig· assembled: to each other by bearinry, so as to fob:® a closed channel or tube with an internal barbulator, .inside which exhaust gases flow, particularly exhaust gases from an automobile vehicle, alone or in association with another fluid, typically air,. írbe face of the channel exposed to these gases or to this mix being the face cladded with the

Ixxx alloy in the first sheet forming the channel., the second forming the internal tnrbnlaior

According to one preferred embodiment, the second .brazing sheet: is composed of an. s.lumin ium alloy with the following composition {% by weight: 5 ;

Si; 0.3 - 1.0 re < 1,0 Co ; 0,3 -- 1.0 Mtr: b.3 -- 1:,0 Mg: 0.3 - 3.0; 3n < S;.0· ri < 0.1. 3?: < 0,3 Cr < 0.3 hi < 2.0 Co < 2.0 Bi <' 3,5 ¥ < 0,5, other elements· f 0,05 each and 0.15 total, the remainder being aiurtinium, clad on its two faces with an aluminium brazing a.L3.oy containing 4% to 15% of silicon and 0,(11 to 0.5% of at least one of the elements do. Be, Bi, Co, is, .Pb, Pd, xb, 1 or MischmetaXi., said two· sheets being, assembled to each ether by 1: lux-free .!. no ander a protective atmosphere.

According to as even more prête;, reo embodiment, the second shoot forming the sorbs lot or äs eoopotwo of an elemin ium alley with· the feel:.Losing compos i f 1on « % by we igln:} ;

Si; G„3 ~ 1,0 Fe < 5,5 Co; 5.35 - 1.0 Μη: 1,0 - 2,0 Mg; 0.30 - 0.7 ton < 0-2 Ti < 0,1 Hr < 0,3 Or < 0,3 Hi < 1,0 Co < 1,0 Bi < 0.5 r < 0.5 other elements < 0.55 each and 5,15 rotai, the remainder being alnminiam, ólaid on ira two faces with an ainminium brazing alles/ containing is in 15% ei silicon and 0.51% ;to 0,5% of at: least one of the: elements iig, Be, Bl, Ce. ha, Pb, bd, Sip 3: os: Mischmetal 1, said fwe sheets also being assesib'led together by rlnçiéss b rating under a protective atmosphère. bn rt her Pore, the first Prating: sheet, forming a channel e:t a tube, .say fee precised with: fins, or separatees on its external lac:·;;:, fhemsaives haring an: aluminium alloy bore Sheet with fat: fallowing, composition {% by weight·,} ;

Sic G, 3 - 1,0 re < i,0 Cue 0,3 - 1,0 Mac 0.5 - 2,0 Mg: 0.3 - 3,0 in < 5,0 T1 < 5,1 Br < 0,3 Or <5,3 Hi < 2,0 Co < 2,0 Bi < 0,5 1 < 5.5 other elements < 0.05 each and 5.15 cotai, the remainder being aiusitonins, o ; adeed on its two faces witch an aluminium. berating alloy containing 1% to 151 of silicon and 0,511 to 0.51 of at lesso one of the elements Mg, Be, Bi, Ce, ta, BP, Pd, Sb, Y or Misehjaetail, and assembled on the channel or tube by fluxless. boatino ander a protective atmosphere,

Preferably, said fins or separators comprise an aluminium allot· cere sheet with the composition f! by weight;:

Si·: 0,3 ~ 1,0 Fe < 5,5 Cu; 0,35 - 1.5 Mr: 1,0 - 2,0 Mgs 0,55 -

Oil ton < 5,2 ti < 5,1 Br < 5,3 Cr < 5,3 Hi < 1,0 Co- < 1,0 Bi < 0.5 f < G.S Other «elements < 5.55 each and 5.IS total, she remainder being aluminium, cladded on its two faces with an aluminium bracing alloy containing 4% so 15% of silicon and 5,51% io :5,5% of at: least: one of the el oner t r -to, Re, bi, Ce, 1,::, Pin Pd, Sfc, Y or Mischmeta.il., nr.·:: assemi:led on the channel or tube by final ess bracing under a protective atmosphère,

According to another variant,, the Prating shoot forming the channel or the tube is cladded op the or rental face of said channel, or tube with, an AMaas; alloy cladding layer and fitted with fins or separators on said clad, assembled by bracing.

Fii.·: i: h ermere, the channel or Silbe may π··ι· obtained fro® an a I ami niais alloy cere sheet having the following composition (% by weight) :

Si: 0.3 - 1.0 Fa < 1.0 Cu; 0.3 - 1,0 Mnx 0.3 ~ 2.0 Mg; Ova - 3.0 Ok -< 0.0 Ti < 0.1 Or < 8/3 Cr e 0/3 Ei <' 2.0 Co < 2,0 M < 0.0 Y < 0.0 other elemexxts. e 0.0.3 each and 0.15 total, the remainder being aiOiSinsdiio cladded on its external face with an aiusd.n inn b rax; a·;: alloy coatainiog is to lit of silicon and 0,011 to 0,5% of at leant one of the előre:/:a hit, Be, Bi, Co, La. Fb, Pd, Sb, V or Mi nehmet:« 11 , and fitted with fins or séparai ·: r s on t a :. s lave:;: assembled ->y fieri ess bracing under a p::oian; ivre a4: meant::;? e. hlso preferably, tiré cHannel or tobe mag' be made from an alumi orate alloy core sheet: having the following compositcon (% by weight):

Si; 0,3 - 1,0 Fe < 0.3 Cxm Ohio - 1,0 Mn: 1/0 - 2:/3 Mg: 0.35 - 0.7 in / .0,2 Ti <: 0.1 or <·" 0.3 Or < 0.3 02 < I/O Co < 1/3 Bi < 3.3 Y < 0.3 other elements? < 0.05 each) .and 0.15 total, the remainder bel?·«: a lia?? ini am, cladded on its external face with an aiustinio® b raring alloy oont&amp;irdng -53 to 15% of .silicon and 0,01%: to 0.5% of at least one of the elements Eg, Be, Bi, Ce, La, fb, Pd, Sb, Y or Mischmetal!, a no fitted with fins or separators on this layer esseisbled by i/unless brazing under a protective .atmosphere.

Finally, these brazing sheets may advantayeoosly be need in the. composition of tsrbniator tabes in a heat: excha-xge·;:, particularly of the type icnpwn by the term EGEC (Eahaast Gas. Bee i tori at ion Cooler ; in which only the exhaust q-sset from an automobile vehicle flow, or of the type known by tire 'term CÀC (Charged air Cooler) in an FEE (Exhaust Css .Recirculation) loop, inside which, a mix of fresh air and exhaust gases from an suko:mobi.i.e vehicle flows.: The invention also applies to this type of heat, exchanger fane in which exhaust gases flow, particularly automobile vehicle exhaust: gases, alone or associated with another flu.!.«:, typically air, made from said bracing sheers, a no alee applies to a heat: exchanger comprising at least one· tabs of this type,

rihriiF.5.i:2;i...r.r..illi...LÍS ingere 1 repress:/: s s erasing she ex with three: layers, the core sheet being rate,benead 2 and the brazing alloy (also called the cladding layer), :: res sox on each of the faces of the core, being: referenced 1.

Figuré. 2 represents a drawing of a fiiba 1 with xxui.ulaxor 3, a fin or separator C'?ot shown, external side, of the tribe), that can be assembled, on the external face of the robe by brazing. Similarly, the turbuiator is assemble;:; on the inaidé fas:·;: of the tube toy brazing. To achieve this, the two faces of the tubas are cladded with a material ted loo the crazing or cladding material. usually .1® the ahixxxx series fro lu tes so 2 1rs the figure).,

Figure 2 repreaents a drawing of the orating sheet used for the tube is figure 2 - tout in which an Aài xxx or Ah'lxxx alloy : ·; :e:re;i; aha cladding has; bees inserted between the tube cote alloy sr.:1 its Allxxx brazing alloy internai cladding.

The tube, core is referenced 3, the Mám alloy external ci adding .is; referenced 4, the: internal cladding also an «Alm alloy is referenced 1,- and tin? nielxxx or Ah'.'xxx alloy intermediate cladding: i.s referenced 2.

Figure t represents a drawing of a babe· 1 with s. tarbniatot 1 according to trie: irrsentioni. said turbuiator itself being composed of a brazing .sheet clad, .and the tube 1 also being made: fror·, a tot axing sheet composed of a core shoot;, typically an ha'ixxx. alloy, cladded on this internal face of the tube with an Ahlxxx alloy cladding .layer 3 and on the external face with an Adi xxx brazing alloy layer 2, on which cocoabod fins are braced.

The indention cons is ins- oil select lag the most appropriate aluminium alloys forming the bracing sheets used, to crake channels err tabes of a heat exchanger· with a a nrbu la torn more purtiniitarly adapt tel to exchanger tubes subjected to- a severe corrosive environment particularly such as tubes through which exhaust gases from at automobile vehicle recirculate.

The turbuiator positioned weithin the tube is designed precisely so as to disturb internal fluid cireclstion and to increase heat; exchange with 'the outside medium.

This turfey later typically cons; i.s tar, at least within tire scope of the invent ion, of a sheet: corrugated .along its length similar to an. exchanger fin or separator·., th.ks embodiment being vieil known to those skilled in the art, as mentioned bn the "Prior art" sect luce.

Still in the context of elements considered fra: the invent: ion. both the tube and the turbuiator are made by bending arid; assembly of braking, sheets, using usual methods known to these skilled in the art:.

The turbuiator i.s .assembled inside the tube by erasing. For this purpose., the bra artig sheet forming the karburátor is composed of an ΑΑΟχχχ alloy dore sheet, cladded on its two faces with an AAirxx fears sins? alloy cladding layer.

The tube Itself is composed of another biasing shoe·· consisiring of an ΛΑ 3 :·: xx alloy cote scree·. ,. and the invention: consists part :otrü.a.b ly of forming a lining by cladding on tire tube internal face, and selecting as AA/shh alloy for this purpose.

According to the: Invention, this same tube coy »0 cladded on Its external face with an AAaxxx alloy cladding lavier to enable brat inn of uncosted fins, also sailed separater®, on said errerns]. face or the tube, err possibly bracing of the tubs? on itself. lie? cladding of the varions alloys cocooning tire bran log one el a ray typically be done by co-rolling, a ccranoaly o:sed method festoon to those skilled in the art: ..

Patent El? 1:68745e 61 of the applicant oisoloses a brssing sheet: compss.ikion consist:ins? of do AA3xr:x alloy core sheet cladded on one or both faces with an AAixxn foraxiog alloy allowing fioaless braving under controlled atmosphere (also celled protective atmosphère), typically nitrogen and/or argon, an a farnsoe ooo.venf:ionaily üssed, as for the docoiobfe process.

This brassing sheet is composed of an aiontlnium. alloy core sheet having the following composition (1 by weight)r

Si; 0.3 - 1.0 fee < i.6 Cn: 0.3 - 1.0 fen: 0,3 - 2.0 feg; 0.3 ~ 3.0 an < 6.0 Î1 < 0,1 2r < 0.3: Cr r 0.3 hi < 2.0 Co < 2,0 Bi < 0.5 Y < 0.5 oilier elements <' 0.0 a each and 0.15 total, the reme Inder feeing a iurainixan, cladded on at least one face with an alumioiam in: mag alloy contain.log 41 to loi of silicon and 0.011 to 0.51 of at least ope of the ri/snot:s Agf Be, Bi, Ce, La, Pb, Pd, Sb, Y o.r Mischmeta11.

An even kois prof cn: red composition: for the core alloy is as follows (A by weight};

Si; 0.5 - 1,0 Fe < 0.3 Cn; 0.35 - 1.0 fen; 1,6 - 2,6 Mgc 0,35 ~ 0,3 fen V 0,2 Ti < 0.1 at < 0,3 Or < 0.3 Ai, < I.. 0 Co < 1:..6 8i < 0,3 1 ο 0.3 of. her· detents < 0.05 each and 6,15 bota.i, the rermrinder· being aluminiirr. and the c : add:, no·; s ; retainian} unchanged.

According to two preferred embodiments of the invent iota this first type of si:ee:: and more advantageous!y the second type cladded on borit faces, is selected for maxing the iurbu la;: ore that can thus be assembled by fioaless brarrng under a protective, atmosphere inside the tube, tiros resulting in a considerable cost saving and preventing any risk related :: o the possible entrainment of residual flax into the circa .it.

Similarly, risse two alloy composit ions, in the same cladding confiqurahion os:· t:»o faces, oa a adcacaiageassiy be esed lid: making Hire: or separators and ::he:. :: assemb! y by i .lax less bracing on the uftcladded, external face of She tebe or channel, in other words ctrentiy on. the core AAoxxx alloy of the tube, in contact with t:he AA4 xxx a.: 1 oy of the fins, according to the abova-utent ioned pref erred composât ions . obvious,ly, still according to the rrtventior, if would aïs::;· be possible to clad the external face of the tufa: or onannei with a cladding layer of AA4xxx .brazing alloy, sc that clad or: unclad .standard bios or separators could be assembled to it by bracing. Furthermore, the two types of sheet, 'with the abose-mentiened compositions nay advantageously be used for making the tube or channel itself, also cladded on the internal face with an A4.1 sex alloy cladding Lave·: and on its externa 1 face with an nhixxx bracing alloy enabling final ess brasing of standard f.lns under a protective atmosphere..

Obviously, the invent lo:n is of great interest: particularly for heat exchangers cost.r : si.no this type of tube and more- particularly heat •exchangers known to those skilled is the art by the nasse: EGFC (Exhaust oss .Recirculation Cooler) , las which only the exhaust gases fro® an aotossotdde vehicle flow, or of ::1).:¾ type known as Charged Mr Cooler (GAG) in an EG.R (Exhaust Gas Recirculation) loop ire ide which, a mix. of fresh air and automobile vehicle exhaust gas mix flows, wherein the media: in both cases particularly corrosive.

For a better understanding, the invention will be fur the)' exposed in tbs following examples, which are however not limiting.

Esamples

Severe.:, sheets of oil6 core alloy and AA4 091 braving alloy were cast with AAlOnO alley sheets and one sheet of each alloy 3929 and 1945. the 391a .alloy had the following compeer tien :(% by weig'ht);

Si ; 0.18 Pú: hilt cu: 9,65 Mn: 1,38 T:i. r 0.(18 other elesaents < in CIS each and 0,15 total, the remainder' being' alandnitsm, f:he 3920 alloy had the following composition (8 by weight:) ; SI; 0,5 Fe; 0.15 Cu: 0,5 Ma; 1,6.5. Bqx :0. S Ti: 0,()8 other .elements < :0,0:5 each: and: (),15 total, roe r odor' being: aluminium, the 4 945 alloy is an AA4045 alloy that: also: contains (),15% of Bi <

Assemblies -were made from these sheets sc as o ear aln the cladding percentages i% of the tots! thickness; indicated in table i be lew, at the end of Use t ransf ormaidon. itta sa assemblies wen; bei::-· and then cold-rolled to produce 0,40 mm thick clad strips 1er the tabes sod 0.20 mm thick clad strips 1er the: turned alors. h 2-hour recovery treatment at 280aC css then applied to these strips after a temperature increase at a rate of 45"C/hoar.

Model tubes with cumulât ors braced according to the Nocoiokd· procès:;; for: references 1 Co 3 in table 1 and £1 useless, brazed for reference 4.., with S: tempe .rate re increase phase: up to 600 °C at. a rate or ebont: iCrC/mia, constant temper ate re for 2 min at ëOCrC and then a ::aoperuture reduetron ai: a rate of about: 50aC/mj.ns ail under nitrogen scavenging wi t h a .flow: of 8 Ï itres/mi a.

The tes ted ·;:·.. π :: :.gnrat.ions ars: shown i.r:. table 1 below.

Configurai its:; 1 applies to· a simple 3936 core alloy tubs: cl added on its; two faites with an ÄA4045 irta a i eg alloy ansi an hhdbOa alloy turbstlator , ifordifynsation 2 is identical est opt. for the addition of an AblDob alloy intermedia to layer between the tote and the hMbsii internai bracing al toy.

Cent remua ti on 3 according to the invent.ioit uses a 3916 core alloy tube cladded on the asternal side with an oMSbb bra ring alloy and on the interna! side with an AiilOhG brazing alloy and a: 391 h core alloy tarbuiator cladded on both sides with an hMilic brut mg alloy.

Brazing for these three oases was done using the Nocoloks? process, with flux.

Configuration 4., according to the invention, uses a 3916 core alloy tube cladded on the sátornál side with an 1214 9 4 o brating alloy and on the internal side with so AilOoO alloy and an ÄA3323 cere alloy turbulatct cladded on both faces with a 4945 bracing alloy (containlog 0.1.31 of Pi) in accordance with tbs above-dent iohed preferred compos!!: ions, In this· case, brazing wan done, fluaiess under a protective atmosphere according to the above-mens ionad potent of the applicant:. table 1: Configuratien of mock-ups tested in corrosion

The rubes corrosion res:; su-us ce ess rested by scare: of a corrosion rear alternating: iasssrsion and èsaeraion in order io reproduce the conditions applied tó CAO idea rood Air Cooler) type exchangers in aa r:GB (Erbaust Gas Reel r cal sd: ion; low-pressure .Loop., The detailed teat corda time used are described in tables 2 and 3 belet?. fa practice:, the test cycle c-.re;:.sra of too repetitions of steps; 1... 2 and 3 and then three repetitions oi: steps 4, 5 and € and the oossipleta -eye: e is repeated soar thousand timer.

Table T: ; Corrosion test paraceters

Table 3; Socpositlo;:; or LI used for the corrosion teat: tin pom)

Saif ate ions sere introduced as: sul far ic acid, nitrate lens as acetic so id and chloride .Lem; as hydrochloric acid·.. rear; each tested ears figuration, the resistance to corrosion ears «validated by necaXioaraphic observation on. a cross-se ::t : on of the tube and of the turbóbator.

The results obtained from ct-aract-erl?,ations· made os samples after 3Ö0 h ere susrmariced in table 4 below, corrosion test after 30:0 hours

The: tubes in -configurations I arid 2 hate severs corrosion that can result in perforations and a signai'leant deterioration of sees brat lira jointe between the robe sod the turbhiator. The- unolad: turbuiators associated with this: type of tube are only slightly corroded:.

On the -other hand., corsr igarat rears 3 and I acoorditng to ..ho invention show veiny litt: be babe corrosion,. often limited to the cladding,. Corrosion of orating joints .is also limited., Turbulators assoc La too with this? type of tube n? o significantly corroded. However this sit tab:, ion is considered to he significantly more favourable-

Indeed, a single perforation on a tube causes a isah of the entire heat evehanger circuit, h leak on a turbuiater causes a .reduction la the heat excharge quality of the exchanger.

Claims (5)

1. Therefore it: is easy ro figure that it is :oox'« important ta maintain the xntegr I r y of the fab« rather than th« i v;?.. egr ; :.y of the tarba la t oχ-. ÖTVÖZETÜK BELSŐ OxődőEId/loFL SS FORRASZTOTT RERTbEBATöRRAL :C..hÁfOT" HŐCSERÉLŐ CSÖVEKHFS S K RB ARA LM I IGÉNYPONTOK x, Elrendezés kát forrasxlopezsel, azzal jellemezve, bogy ax első lemez AAzxxx szériája ötvösét, aminek egyik olOíSiáro Akii XXX öt vöt étből Lévő réteg van piattiroxva, hagy a xításodik Ζοη;,a AAoxxx szériájh ötvözet, sRÍnsk minőkét oldalára AA·; ;·::··: x :ötvözetböl lévő .réteg ran plattirozva, hogy a xeroxok úgy vannak egymással forrasztás révén összekapcsolva, Rogy agy tért csatorna vagy egy eső képződik,· agy belső keverödobozza1, arain keress fül kipufogó gázok, elsősorban gépjármű kipufogó gazok áramlanak, önállón:: vagy más fluid közeggel együtt, hogy a csatorna oldala, api ezeknek a gázoknak vagy reverékakno 1: vau kitéve, az az oldal, ami az első, a csatorííát képező lemez AAlxxz ötvözetből lévő réteggel piaótiroxot ·: c· Idái a, árig a második 'tapez a belső keverödobozi: alkotja, z. Az 1. igénypont szerinti elrendezés két forraazlemexxel, azzal jel leverve, hogy a második forrás ziemet sűlyszáxalakos összetétele a következd; Sic 0,3 - 1,0 Fa < 1,0 Cu ; 0,3 - 1,0 Mn : 0,3 ~ 3,0 Mg; 0,3 - 3,0 3xs < 0,0 ti < 0,1 Ez < 0,3 Cr < 8,3 Ni < 2,ü Co < 2,0 Bt < 0,5 V < 0,5 valamint további elepek 0,05%—nál. kisebb, össxeaen 0, iSk-nái kisebb mennyiségben, és a marsarkban aixmo:niam, és mindkét oldalán egy olyan alumínium :tor.raszf,óöU;vözsr:tta.l van plattirozva, api bartaimaz 3-1.5¾ szil lei nmet és 0,01-0,5%~ban tartalmaz legalább egyet a kővetkező elemek kösd!:; Ag, Se, Si, Ce, La, PP, Pd, Sfe, Y vagy Mischmetal!, ahol a két lemez ioiyasxtösze:r nélkül·! védőgázos frurrasztással van összekapcsolva, 3, A 2, igénypont szerinti elrendezés két xorraoxlonexxe; , azzal teiiepezve, hogy a rá sző t forrasz!emez sülyszázalékos összetétele a kővetkező; Si; 0,3 - î, 0 FS <' O, 5 Co ; 0,35 - 1,0 Mrs ; 1,0 » 2y0 I4q : C, 35 - S, 7 Sn < (3,2 Ti < 0,1 Zr < 0,3 Cr <: 0,3 Ni < 1,0 Co < 1, 0 £i < 5,5 Y < 0,3, valamint további elemek 0,05%-nâI kisebb, összesen 0, 15%~üái 'kisebb meenyissgben, és a maradékban alomioius·, és mindkét oldalán ogy olyan aluminium foriütszzdötvözeréei var; pXattirnzv.a, ami tartalmaz 4-15% sí;i 1 ieiümxü: és 0,01-0,5%-bat tartalmaz lese ; ii:d egyet a következő elemek. közül; eg, Be. 83, Ce, La:, Pb, Pd, 00, Y vagy iö. e oiumetai 1, akoi a két ! amse iloiyasztószer nélküli védőgázos Forrasztással van összekapcsolva, i Az. I - 3. igénypontok bármelyike a ser inti elrendezés két Forraszle:me;:.zel, azzal i ·=~ 1 lesen'.··:,, bogy az első, a csatorna t képesé leises külső oldalán bordák nagy közbülső betétek vannak, amik a;: alábbi sűiyszázalekos összetételű ai.u:ib. oi vita ötvözetből készült: magiamé zbb.1 vannak előállítva:. 01; 0,3 - 1,0 Fe < 1,0 Cn; 0,3 -- 1,0 Mn ; 0,3 - 2,0 Mg : 0,3 - 3,0 in < 6,0 Ti < G, I Zr < 0,3 (0: < 0,3 Bi. <: 2,8 Co < 2,(3 Bi. < 0,5 Y < 0,5:, valamint: további elemek 0,05%-n.ál kisebb, osssesat 0,i5%--nái kisebb mennyiségben, és a ma tsdé^.ban a.tüiaininm, at···.:, mindkét oldalán olyan aluminium forrasztóotvözettel van plattirozva, ami tartalmas 4-15% se i 1 íölömet és 0,01-0,51-ban tartalma::, legalább egyet, a kövei:késé elemek körül: Lg, Be, Bi, Ce, La, Pb, Pd, Sb, Y vagy Mischmetal!, anoi a két lemez xolyasztoszer nélküli védőgázos Forrasztással var: oeszekaocae . v a .
2. 5, Az 1 ·· 4. igénypontok bármelyik« szerinti elrendezés két torra:"ztome:::,--1., azzal, jellemezve, hogy a csatorna külső oldalán bordák vagy közbülső betétek varinak, amik Si : 0,3 - 1,0 Fe < 5,5 Co : 0,35 - 1,5 Mn ; 1,0 - 2,0 Mg : 0,35- - 0,7 Zn < 0,2 Ti < 0,3: Zr < 0,3 Cr < 0,3 Bi. < 1,8 Co < 1,5 Bi < 0,5 Y < 0, 0 va.i.amint továbbá elemek 0,05%-nái k i.(5;, összesen 0, Idáméi kisebb mennyiségben, es a maradékban aluminium, ami mindkét oldalár: olya« airrminium iörzasztóotvözettel var: ólat: t i re zva, ami tartalmaz -1-10% szi líciumot és 0,ül-0,5%-ban t·::r ··s 1 :t iz legalább egyet a következő elemek közül; Ag, Be, Bi, Ce, La, Bb, Pd, ab, Y vagy Miscbmetali, ahol. a két lemez tolyasztószer nélküli védőgázos: forrasztással van összeizaposolve.
3. 6. Άζ 1 - 3, igénypontok hármsiyiSce szerinti elrendezés két forraaziemetzel, azzal jellemezve, hogy a csatorna külső oldalán egy Asixxx ötvözetből lévé borítással van ellátva,· és esen a rétegen összetörrasztotk bordák vagy közbülső betétek vannak.
4. 7, Az 1 ·· 3. igénypontok burrael vite szerinti ebrendezés két britre sz Lemezzelazzal jellemezve, hogy a csat: or na a:; alábbi súly százalékos: összetételű alned ni um. ötvözetből készült mag ; est zböi vei; előállí t va ; Bi; Cg 3 - 1,0 Pe < 1,0 Cu ; 0,3 - 1,0 Un:; 0,3 - 2,0 Mg; 0,3 - 3,0 kn < 0,0 ti < 0,1 2;; < 0,3 Cr <' 0,3 Hl < 2,0 C:> < 2,0 Bi < 0,5 Y < 0,5 , valamint: további eleitek :ö,05%--nél kisebb, összesen 0,151~nái kisebb menny.; senses, és a maradékban alumínium, ami a külső gbisián olyan aluminium borrasztőötvózefctel van piattirosva, ami tartalma z 4-15¾ ssiliclymbt és 0, öl-O, 51-baa tar te· Imaz iegaiébb egyet, a következe elen.et: közöl; Ag, Se, Si, Ce, La, Pb, Pd, Ob, :: vagy Mbstbmetall, ahol a borító rétegen bordák vagy közbülső betétek vannak, amik teiyasztbazer nélküli védőgázos torzasztássai vannak összekapcsolva.

   3, Az 3 - 3 , igénypontok bármelyike szerinti elrendezés kér iözrasíziemesaei, azzal gel Iemszve, hogy a csatorna az alábbi sülyszázsiékos összetételű alorcdni.nm ötvözetből készült stag lemez bői van előállítva: Si; 0, 3 - 1,0 Pa < Ü,S Cu : 0, 31 - 1, 0 Mn. ; 1,0 - 2,0 Mg ; :0,35 - 0,7 2n < 0,2 Ti < ö, i 2r < 0,3 Cr < 0,3 dl < 1,0 Cc < 1,0 Bi < 0,3 Y < 0,5, valamint további elemek 0,03%-sá.l kisebb, összesen Csillánál kisebb mennyiségben, és a mar adásban aluminium, ami a külső oldalán olyan aluminium lorrasatöö;: vezet tel van plattirözva, ami tartalmaz A-lnt sgilleigmot és 0,01-0,5%-ban tartalmaz. legalább egyet a következő elemet korül; Ag, Be, Bi, Ce, La, Pb, Pd, Se, Y vagy Misohmetsli, ahol &amp; borító rétegen bordák vagy közbülső1 betétiek vannak,,· amik. roiyasztószer nélküli védögázas torzasztássai vannak őss zekapeso1va.

   5, Az 1 - B. igénygontcrk. bármelyike szerinti elrendezés kél;, forrasziemezzei, azzal jellemezve, horsy egy nőcserélő alkatrészét képezi. 10, A 3, Laénypont szerinti elrendezés két forrasziemezzei, azzal jellemezve, hogy egy olyan hőcserélő alkatrészét képezi, ami íSGEC (bxhanst Cas Peeir eulatien Cooler} tévőn Ismert, és azzáre Lag gépjármű kipufogó gázok áramlanak benne, 11. A .1. igénypont szerinti tizenhete s két: forrasziemezzei, azzal jaiiemezye, hogy agy olyan hőcserélő alkatrészét képezi, ami RAB : Re:: ro id:. ssenr a' Air Stíraiimentation, angolul CAC „Cnarged Air Cooler"; kipufogógáz visszavezetéssel EGR (Rxheust Gaz Recirculation'} iiéven iáiéért, és levegő, valakiét gépjámü ki pis fogé górok keveréke éraolik benne., té, kőcseré fő cső, akiben kipufogó gázok, különbség gépi é müvek kipufogó gangé önállóén vagy egyéb folyékony köteggel együtt áraíííianak, és aki as 1 ~ 8, igénypontok bé melyike svertßfi clr-v.cocos sserial:i van aléaIIÍrva.
5. 13, Hőcserélő, aszal jel lotse eve, bogy tartalsias legalább egy, a 12, igénypont s ver fűti csövet.