JPS6342547B2 - - Google Patents
Info
- Publication number
- JPS6342547B2 JPS6342547B2 JP55097357A JP9735780A JPS6342547B2 JP S6342547 B2 JPS6342547 B2 JP S6342547B2 JP 55097357 A JP55097357 A JP 55097357A JP 9735780 A JP9735780 A JP 9735780A JP S6342547 B2 JPS6342547 B2 JP S6342547B2
- Authority
- JP
- Japan
- Prior art keywords
- brazing
- flux
- aluminum
- heat exchanger
- tube
- 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
- 238000005219 brazing Methods 0.000 claims description 52
- 230000004907 flux Effects 0.000 claims description 47
- 229910052782 aluminium Inorganic materials 0.000 claims description 19
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 19
- 239000011162 core material Substances 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 10
- 229910000838 Al alloy Inorganic materials 0.000 claims description 8
- 239000007864 aqueous solution Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- 239000012535 impurity Substances 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 229910052725 zinc Inorganic materials 0.000 claims description 3
- 229910021364 Al-Si alloy Inorganic materials 0.000 claims description 2
- 229910013647 LiCl—LiF Inorganic materials 0.000 claims description 2
- 239000000945 filler Substances 0.000 claims description 2
- 206010016766 flatulence Diseases 0.000 claims 1
- 239000011592 zinc chloride Substances 0.000 claims 1
- 235000005074 zinc chloride Nutrition 0.000 claims 1
- JIAARYAFYJHUJI-UHFFFAOYSA-L zinc dichloride Chemical compound [Cl-].[Cl-].[Zn+2] JIAARYAFYJHUJI-UHFFFAOYSA-L 0.000 claims 1
- 238000005260 corrosion Methods 0.000 description 18
- 230000007797 corrosion Effects 0.000 description 18
- 239000000463 material Substances 0.000 description 13
- 230000000694 effects Effects 0.000 description 8
- 238000009826 distribution Methods 0.000 description 5
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000005238 degreasing Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 239000012190 activator Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 238000004210 cathodic protection Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- PQXKHYXIUOZZFA-UHFFFAOYSA-M lithium fluoride Chemical compound [Li+].[F-] PQXKHYXIUOZZFA-UHFFFAOYSA-M 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000005275 alloying Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- GPGMRSSBVJNWRA-UHFFFAOYSA-N hydrochloride hydrofluoride Chemical compound F.Cl GPGMRSSBVJNWRA-UHFFFAOYSA-N 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 229910000679 solder Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Landscapes
- Prevention Of Electric Corrosion (AREA)
- Laminated Bodies (AREA)
Description
本発明はアルミニウム製熱交換器をフラツクス
ろう付する方法に関するもので、従来のフラツク
スろう付法に比べて、フラツクス使用量を少なく
してコスト低減を計ると共に、耐孔食性のすぐれ
た熱交換器を提供するものである。
従来アルミニウムのフラツクスろう付法には
ZnCl2を含む塩化物−弗化物系の混合フラツクス
を水に溶かして使用している。
この際ろう付が完壁に遂行されるためには
60wt％以上のフラツクス水溶液にし、これに熱
交換器を浸漬し、フラツクスを全面に塗布して、
ろう付を行わなければならない。なお、ろう付条
件は595〜620℃に数分間保持する加熱条件が適切
である。
ところで上記フラツクスろう付によるとフラツ
クス使用量が熱交換器１m2当り100gr以上となる
ため熱交換器１台（自動車熱交で３m2以上）を作
るのにかなりの量を必要とすることがわかる。フ
ラツクスは純度の良いNaCl、KCl、LiCl、LiF、
ZnCl2などの薬品を用いなければならないため、
フラツクスろう付のコストは非常に高くなる。
このことからろう付雰囲気を水分の少ない状態
に調整する方法、例えば乾燥空気あるいはN2ガ
スをろう付炉内へ導入し内部の露点を低い状態に
管理することによつて熱交換器に塗布するフラツ
クス量を極端に少なくする方法が開発された。こ
の方法によるとフラツクス水溶液濃度として約
30wt％（以下wt％を％と略記）以下でろう付が
可能である。
しかしフラツクス量を少ない状態にしてろう付
した熱交換器は腐食性雰囲気に曝露すると短期間
でチユーブに貫通孔食が発生する場合がある。
この理由はフラツクス量を少なくするとろう付
後熱交換器表面に析出、拡散するZnの絶対量が
少なくなり陰極防食効果が失われてしまうからで
ある。
陰極防食効果が完全に発揮されるためにはフラ
ツクス濃度として60％以上が必要であり、この条
件でろう付した場合チユーブ全体でZnの分布は
第１図に示すようなパターンとなる。この第１図
はろう付を行なつた後のアルミチユーブ表面付近
のZn分布曲線を示すもので横軸にアルミチユー
ブ表面からの深さをとり、縦軸にはZn濃度をと
つたものでZnの拡散する深さは100〜200μであ
る。従つてこれを腐食性雰囲気に曝露しても電位
の低いZnを含んだ表面層（100〜200μ）が優先的
に腐食するため孔食が深く進行しないことが明ら
かとなつている。
以上の理由からフラツクスの使用量を少なくす
ると耐孔食性が低下するという欠点を生ずること
がわかる。
本発明はかかる点に鑑み種々研究の結果フラツ
クスを少ない状態にしてろう付しても耐孔食性に
優れた熱交換器を提供するフラツクスろう付法を
開発したものでZn0.1〜2.0％、Mn1.5％以下、残
部アルミニウム及び不純物からなるアルミニウム
合金のフインとAl−Si合金からなるろう材をア
ルミニウムまたはアルミニウム合金の心材の片面
又は両面にクラツドしたブレージングシートから
なる成形部品或いは溶接チユーブとを組み合せた
熱交換器をZnCl2を４〜12％含むNaCl−KCl−
LiCl−LiF系フラツクスを用いろう付することを
特徴とするもので上記においてアルミニウム製熱
交換器を５〜40％のフラツクス水溶液に浸漬し十
分乾燥して水分を除去した後、露点を−４℃以下
に調整した加熱炉でろう付することを特徴とする
アルミニウムのフラツクスろう付け法である。
しかして本発明においてフイン材となるアルミ
ニウム合金に添加したZnはろう付後飛散するこ
となく残存し、フイン全体の電位を低くする効果
をもたらす。フラツクス使用量が少ない場合には
成型部品あるいは溶接チユーブ全体にZnの拡散
層が不均一でしかも第１図に示すようなZn濃度
分布にならないため、局部的に孔食が進行する可
能性を有する。この場合に前記のフインが犠牲陽
極となり成型部品あるいは溶接チユーブを保護す
る働きを持つものである。ブレージングシートの
ろう材におけるSiの添加はろう材の融点を下げろ
う付時の流動を可能ならしめフインとチユーブと
の接点にフイレツトを形成させ接合性を向上させ
る合金元素として添加するものである。
しかして本発明においてフイン材を構成する合
金成分を上記範囲に限定した理由は次の通りであ
る。
フイン材におけるZnの含有量が0.1％未満では
フイン材が犠牲陽極効果を発揮する程十分に電位
が低くならず成型部品あるいは溶接チユーブにお
けるZn未拡散層との間の電位が接近しそこから
孔食が深く進行する恐れがある。また2.0％を越
えて添加しても、その効果は飽和すると共に、フ
イン材の融点が低下し、ろう付時に座屈を起こし
易くなる。なおZnの最も望ましい添加量は0.3〜
1.5％の範囲である。
またMnを1.5％以下としたのは1.5％を越えて
添加しても強度及び耐座屈性上昇の効果が飽和す
るばかりでなく塑性加工性が非常に悪くなるから
である。
ろう材はAl−5.5％Si（JIS4043）、Al−7.5％Si
（JIS4343）、Al−10％Si（JIS4045）及びAl−12％
Si（JIS4047）が一般的である。
チユーブ材料を構成するブレージングシートの
心材はろう付可能なアルミニウム合金であれば特
に限定するものではないが、一般的にはAl−
1.1Mn（JIS3003）が知られており、ブレージング
シートとしてはJIS BA12（4343／3003／4343）
が良く使用されている。
なおフラツクスにおけるZnCl2は酸化皮膜除
去、ろうの濡れ促進などの活性剤として働くと共
にアルミニウム表面に析出しまた内部へ拡散する
ことによつて、耐孔食性を向上させる役割を担つ
ている。
フラツクスに含有されるZnCl2の濃度を上記範
囲に限定した理由は４％未満では活性剤としての
効果が充分でなく、また12％を越えて添加した場
合フラツクス全体の融点が低くなり過ぎて良好な
ろう付性が得られないからである。
またフラツクス水溶液の濃度を上記範囲に限定
した理由は５％未満では熱交換器へのフラツクス
付着量が少ないため、満足なろう付が得られな
い。また40％を越えた場合にはフラツクス使用量
が多くなり、従来のフラツクスろう付と大差なく
コスト高になるからである。
フラツクスを付着させ、十分乾燥させてから露
点を−４℃以下に調整した加熱炉でろう付するの
はアルミニウムの酸化を防ぎ出来るだけ少量のフ
ラツクスでろう付を可能ならしめるためで、露点
を−４℃以下と限定した理由はこれを越えると、
フラツクスが少量になつた場合満足なろう付が得
られないからである。
なお露点の調整には乾燥空気あるいはN2、Ar
のような不活性ガスのいずれかが望ましい。
以下本発明を実施例について詳細に説明する。
実施例 １
第１表に示す組成のフイン材用合金を金型鋳造
し両面を面削して550℃にて３時間均質化処理し
た後、直ちに熱間ロールで厚さ５mm迄圧延した。
これを0.2mm迄冷間圧延し、ここで360℃で２時間
の焼鈍を行なつて0.16mm迄冷間圧延後、スリツタ
ーによつて巾26mm×ｌの条材とした。この条材を
コルゲートマシンにかけてフインピツチ４mm、高
さ20mmのコルゲートフインを作製した。
一方板厚0.4mm、巾60mmの条材BA11PC（ろう材
Al−7.5％Si片面心材Al−1.1％Mn）のブレージ
ングシートから溶接扁片チユーブを作り、これと
上記コルゲートフインを第２図のように組み立て
熱交換器の模擬コアーとした。
これらを脱脂後治具で固定し、20％フラツクス
水溶液に浸漬して、全面にフラツクスを塗布し十
分に乾燥後、乾燥空気で雰囲気の露点を−10℃に
調整した炉内に装入し、610℃３分間のろう付を
行なつた。なおこの時用いたフラツクスはZnCl2
を８％含有するNaCl−KCl−LiCl−LiF系の
ALCOAフラツクス＃33であつた。
このようにして得られたコアーサンプルについ
ては５％塩水噴霧テスト（JISZ2371）を６ケ月
間行つた後チユーブに発生した孔食深さを測定し
た。最大孔食深さが0.2mm以下であれば耐孔食性
良好と判定した。
またろう付性及びフインの耐座屈性については
〇良好、△やや良好、×不良の３段階で評価した。
The present invention relates to a method of flux brazing aluminum heat exchangers, which reduces costs by reducing the amount of flux used compared to conventional flux brazing methods, and provides heat exchangers with excellent pitting corrosion resistance. It provides: The conventional flux brazing method for aluminum
A chloride-fluoride mixed flux containing ZnCl 2 is used by dissolving it in water. At this time, in order to perform the brazing perfectly,
Make a flux aqueous solution of 60wt% or more, immerse the heat exchanger in this, and apply the flux to the entire surface.
Must be brazed. In addition, the appropriate brazing conditions are heating conditions in which the temperature is maintained at 595 to 620°C for several minutes. By the way, according to the above-mentioned flux brazing, the amount of flux used is more than 100 gr per 1 m 2 of heat exchanger, so it can be seen that a considerable amount is required to make one heat exchanger (more than 3 m 2 for an automobile heat exchanger). . Fluxes include high purity NaCl, KCl, LiCl, LiF,
Because chemicals such as ZnCl 2 must be used,
The cost of flux brazing is very high. For this reason, there are methods to adjust the brazing atmosphere to a low-moisture state, such as introducing dry air or N 2 gas into the brazing furnace and controlling the internal dew point to a low state to apply it to the heat exchanger. A method has been developed to extremely reduce the amount of flux. According to this method, the flux aqueous solution concentration is approximately
Brazing is possible at less than 30wt% (hereinafter wt% is abbreviated as %). However, if a heat exchanger brazed with a small amount of flux is exposed to a corrosive atmosphere, the tubes may undergo pitting corrosion in a short period of time. The reason for this is that if the amount of flux is reduced, the absolute amount of Zn precipitated and diffused on the surface of the heat exchanger after brazing will be reduced, and the cathodic protection effect will be lost. In order for the cathodic protection effect to be fully exhibited, a flux concentration of 60% or more is required, and when brazing under these conditions, the distribution of Zn throughout the tube will have a pattern as shown in Figure 1. Figure 1 shows the Zn distribution curve near the surface of the aluminum tube after brazing.The horizontal axis shows the depth from the aluminum tube surface, and the vertical axis shows the Zn concentration. The diffusion depth is 100-200μ. Therefore, it has become clear that even if this material is exposed to a corrosive atmosphere, the surface layer (100 to 200 μm) containing Zn, which has a low potential, corrodes preferentially and pitting corrosion does not progress deeply. For the above reasons, it can be seen that reducing the amount of flux used results in a disadvantage that the pitting corrosion resistance decreases. In view of these points, the present invention has been developed as a result of various researches and is a flux brazing method that provides a heat exchanger with excellent pitting corrosion resistance even when brazed with a small amount of flux. A molded part or a welded tube consisting of an aluminum alloy fin with Mn of 1.5% or less, the balance being aluminum and impurities, and a brazing sheet in which a brazing filler metal made of an Al-Si alloy is clad on one or both sides of an aluminum or aluminum alloy core material. NaCl−KCl− containing 4–12% ZnCl 2 in the combined heat exchanger
The aluminum heat exchanger is immersed in a 5 to 40% flux aqueous solution, thoroughly dried to remove moisture, and then the dew point is reduced to -4°C. This is an aluminum flux brazing method characterized by brazing in a heating furnace adjusted as follows. Therefore, in the present invention, the Zn added to the aluminum alloy serving as the fin material remains without scattering after brazing, and has the effect of lowering the potential of the entire fin. If the amount of flux used is small, the Zn diffusion layer will be uneven throughout the molded part or welded tube, and the Zn concentration distribution will not be as shown in Figure 1, so there is a possibility that pitting corrosion will progress locally. . In this case, the fins serve as a sacrificial anode to protect the molded part or weld tube. Si is added to the brazing sheet brazing material as an alloying element that lowers the melting point of the brazing material, enables flow during brazing, forms a fillet at the contact point between the fin and tube, and improves bonding performance. However, the reason why the alloy components constituting the fin material in the present invention are limited to the above range is as follows. If the Zn content in the fin material is less than 0.1%, the potential of the fin material will not be low enough to exert a sacrificial anode effect, and the potential between the molded part or the Zn undiffused layer in the welded tube will approach and pores will form. There is a possibility that the eclipse will progress deeply. Moreover, even if it is added in excess of 2.0%, the effect is saturated and the melting point of the fin material decreases, making it more likely to buckle during brazing. The most desirable addition amount of Zn is 0.3~
It is in the range of 1.5%. Furthermore, the reason why Mn is set to 1.5% or less is that if it is added in excess of 1.5%, not only the effect of increasing strength and buckling resistance is saturated, but also the plastic workability becomes extremely poor. Brazing metal is Al-5.5%Si (JIS4043), Al-7.5%Si
(JIS4343), Al-10%Si (JIS4045) and Al-12%
Si (JIS4047) is common. The core material of the brazing sheet constituting the tube material is not particularly limited as long as it is a brazable aluminum alloy, but generally Al-
1.1Mn (JIS3003) is known, and the brazing sheet is JIS BA12 (4343/3003/4343).
is often used. ZnCl 2 in the flux acts as an activator to remove oxide films and promote wetting of the solder, and also plays a role in improving pitting corrosion resistance by precipitating on the aluminum surface and diffusing into the interior. The reason for limiting the concentration of ZnCl 2 contained in the flux to the above range is that if it is less than 4%, it will not be effective as an activator, and if it is added in excess of 12%, the melting point of the entire flux will be too low, making it unsuitable. This is because good brazing properties cannot be obtained. The reason why the concentration of the aqueous flux solution is limited to the above range is that if it is less than 5%, the amount of flux adhering to the heat exchanger is small, making it impossible to achieve satisfactory brazing. Moreover, if it exceeds 40%, the amount of flux used will increase, and the cost will be high, not much different from conventional flux brazing. The reason why flux is applied, thoroughly dried, and then brazed in a heating furnace with a dew point adjusted to below -4°C is to prevent oxidation of the aluminum and enable brazing with as little flux as possible. The reason why we limited it to 4℃ or less is that if it exceeds this,
This is because if the amount of flux is too small, satisfactory brazing cannot be achieved. To adjust the dew point, use dry air, N 2 or Ar.
Any inert gas such as is preferred. The present invention will be described in detail below with reference to examples. Example 1 An alloy for fin material having the composition shown in Table 1 was cast in a die, both sides were faceted, homogenized at 550° C. for 3 hours, and then immediately rolled with hot rolls to a thickness of 5 mm.
This was cold rolled to 0.2 mm, then annealed at 360° C. for 2 hours, cold rolled to 0.16 mm, and then made into a strip with a width of 26 mm×l using a slitter. This strip was run on a corrugating machine to produce corrugated fins with a fin pitch of 4 mm and a height of 20 mm. On the other hand, strip material BA11PC (brazing metal) with a plate thickness of 0.4 mm and a width of 60 mm
A welded flake tube was made from a brazing sheet of Al-7.5%Si (one-sided core material Al-1.1%Mn), and this and the above corrugated fin were assembled as shown in Figure 2 to form a simulated core of a heat exchanger. After degreasing, fix them with a jig, immerse them in a 20% flux aqueous solution, apply flux to the entire surface, dry them thoroughly, and then charge them into a furnace whose dew point is adjusted to -10°C with dry air. Brazing was performed at 610°C for 3 minutes. The flux used at this time was ZnCl 2
NaCl-KCl-LiCl-LiF system containing 8% of
It was ALCOA flux #33. The core sample thus obtained was subjected to a 5% salt water spray test (JISZ2371) for 6 months, and then the depth of pitting corrosion occurring in the tube was measured. Pitting corrosion resistance was judged to be good if the maximum pitting depth was 0.2 mm or less. The brazing properties and buckling resistance of the fins were evaluated in three grades: ○ good, △ somewhat good, and × poor.
【表】
以上の結果を第１表に併記した。
第１表に示すように本発明のフイン材である
No.1〜No.6を用いたコアチユーブの最大孔食深
さはいずれも0.16mm以下で、チユーブの耐孔食性
は優れている。それに比較してZnの少ないNo.7
はチユーブに貫通孔食が認められ、またZnの多
いNo.8はフイン融点低下のためフインの耐座屈
性が劣つている。
実施例 ２
Zn0.8％、Mn1.1％、残部アルミニウム及び不
純物からなるアルミニウム合金を、実施例１と同
様に作製し、さらにこれを加工しコルゲートフイ
ンとした。但しこの場合の最終板厚は0.13mmとし
た。
また板厚0.4mmのBA11PCブレージングシート
を実施例１と同様に扁平チユーブとし、第２図の
ごとくフインと組み立て、脱脂後第２表に示す濃
度のフラツクス水溶液に浸漬して全面にフラツク
スを塗布した。
水分を除去するため十分に乾燥後第２表に示す
ように乾燥空気で雰囲気の露点を調整した炉内へ
装入し、610℃３分間のろう付を行なつた。
ろう付性を評価した後、実施例１と同様に塩水
噴霧テストを行ないチユーブに発生した孔食の深
さを測定した。これらの結果を第２表に併記し
た。[Table] The above results are also listed in Table 1. As shown in Table 1, the fin material of the present invention is
The maximum pitting corrosion depth of the core tubes using No. 1 to No. 6 was all 0.16 mm or less, and the pitting corrosion resistance of the tubes was excellent. Compared to that, No.7 has less Zn.
Through-pitting corrosion was observed in the tube, and No. 8, which contained a large amount of Zn, had poor fin buckling resistance due to a lower fin melting point. Example 2 An aluminum alloy consisting of 0.8% Zn, 1.1% Mn, and the balance aluminum and impurities was produced in the same manner as in Example 1, and further processed into a corrugated fin. However, the final plate thickness in this case was 0.13mm. In addition, a BA11PC brazing sheet with a plate thickness of 0.4 mm was made into a flat tube as in Example 1, assembled with fins as shown in Figure 2, and after degreasing, it was immersed in an aqueous flux solution with the concentration shown in Table 2 to apply flux to the entire surface. . After sufficiently drying to remove moisture, the material was charged into a furnace whose dew point was adjusted with dry air as shown in Table 2, and brazing was performed at 610° C. for 3 minutes. After evaluating the brazeability, a salt spray test was conducted in the same manner as in Example 1 to measure the depth of pitting corrosion occurring in the tube. These results are also listed in Table 2.
【表】
本発明であるNo.10〜No.16においてはろう付
性が優れておりコアーチユーブに発生した最大孔
食深さは、いずれも0.13mm以下でチユーブの耐孔
食性も非常に優れていた。
それに比較してフラツクス水溶液の濃度が本発
明の範囲を外れるNo.17〜No.19ではろう付性が
劣り、No.20ではろう付性、耐孔食性とも優れて
いるがフラツクス使用量が多いのでコスト高にな
るのはいうまでもない。
実施例 ３
Zn0.5％、Mn0.8％、残部アルミニウム及び不
純物からなるアルミニウム合金を実施例１と同様
に作製し、さらにこれを加工してコルゲートフイ
ンとした。但しこの場合の最終板厚は0.18mmとし
た。
また板厚0.4mmのBA11PCブレージングシート
を実施例１と同様に扁平チユーブとし第２図のご
とく組み立て脱脂後治具で固定して第３表に示す
ように各濃度のZnCl2を有するALCOAフラツク
ス＃33の30％水溶液に浸漬、乾燥後N2ガスで雰
囲気の露点を−15℃に調整した炉内に装入して
610℃で３分間ろう付を行なつた。
このようにして得られたコアーサンプルのろう
付性を評価した後実施例１と同様に塩水噴霧テス
トを行いコアチユーブに発生した孔食の深さを測
定した。
これらの結果を第３表に併記した。[Table] Nos. 10 to 16 according to the present invention have excellent brazing properties, and the maximum pitting depth that occurred in the core tube is 0.13 mm or less, and the pitting corrosion resistance of the tube is also very good. Ta. In comparison, Nos. 17 to 19, in which the concentration of the flux aqueous solution is outside the range of the present invention, have inferior brazing properties, while No. 20 has excellent brazing properties and pitting corrosion resistance, but uses a large amount of flux. Needless to say, the cost will be high. Example 3 An aluminum alloy consisting of 0.5% Zn, 0.8% Mn, the balance being aluminum and impurities was produced in the same manner as in Example 1, and further processed into a corrugated fin. However, the final plate thickness in this case was 0.18 mm. In addition, a BA11PC brazing sheet with a thickness of 0.4 mm was made into a flat tube as in Example 1, assembled as shown in Fig. 2, fixed with a jig after degreasing, and ALCOA flux # with various concentrations of ZnCl 2 as shown in Table 3. After being immersed in a 30% aqueous solution of 33 and dried, it was charged into a furnace whose dew point was adjusted to -15℃ using N2 gas.
Brazing was performed at 610°C for 3 minutes. After evaluating the brazeability of the core sample thus obtained, a salt spray test was conducted in the same manner as in Example 1 to measure the depth of pitting corrosion occurring in the core tube. These results are also listed in Table 3.
【表】
第３表に示すように本発明のNo.21〜No.23に
おいてはろう付性耐孔食性のいずれも優れてい
た。
それに比べてフラツクス中のZnCl2濃度が本発
明の範囲を外れるNo.24〜No.25はフラツクスの
活性度が低下し、ろう付が不可能であつた。
以上説明した如く本発明によればろう付性良好
で且つ耐孔食性の優れたアルミニウム製熱交換器
を低コストで得られるもので工業上著しい効果を
奏するものである。[Table] As shown in Table 3, Nos. 21 to 23 of the present invention were excellent in both brazing and pitting corrosion resistance. In comparison, in No. 24 to No. 25, in which the ZnCl 2 concentration in the flux was outside the range of the present invention, the activity of the flux decreased and brazing was impossible. As explained above, according to the present invention, an aluminum heat exchanger having good brazing properties and excellent pitting corrosion resistance can be obtained at a low cost, and has a significant industrial effect.
第１図はフラツクスろう付によつて生ずるアル
ミニウム表面層における断面のZn濃度分布図、
第２図は本発明に用いたコルゲートフイン偏平チ
ユーブの熱交換器の斜視図である。
１……Zn濃度分布曲線、２……偏平チユーブ、
３……コルゲートフイン。
Figure 1 is a cross-sectional Zn concentration distribution diagram of the aluminum surface layer produced by flux brazing.
FIG. 2 is a perspective view of a corrugated fin flat tube heat exchanger used in the present invention. 1...Zn concentration distribution curve, 2...flat tube,
3...Colgate Finn.
Claims (1)
ミニウム及び不純物からなるアルミニウム合金の
フインとAl−Si合金からなるろう材をアルミニ
ウムまたはアルミニウム合金の心材の片面又は両
面にクラツドしたブレージングシートからなる成
形部品あるいは溶接チユーブとを組み合せた熱交
換器をZnCl2を４〜12wt％含むNaCl−KCl−
LiCl−LiF系フラツクスを用いろう付することを
特徴とするアルミニウム製熱交換器のフラツクス
ろう付法。 ２ アルミニウム製熱交換器を５〜40wt％のフ
ラツス水溶液に浸漬し、十分乾燥して水分を除去
した後、露点を−４℃以下に調整した加熱炉でろ
う付することを特徴とする特許請求の範囲第１項
記載のアルミニウム製熱交換器のフラツクスろう
付法。[Claims] 1. Aluminum alloy fins consisting of 0.1 to 2.0 wt% Zn, 1.5 wt% or less Mn, and the balance aluminum and impurities, and a brazing filler metal consisting of Al-Si alloy on one side of an aluminum or aluminum alloy core material or A heat exchanger combining a molded part made of a brazing sheet clad on both sides or a welded tube is made of NaCl−KCl− containing 4 to 12 wt % of ZnCl2.
A flux brazing method for aluminum heat exchangers, characterized by brazing using LiCl-LiF-based flux. 2. A patent claim characterized in that an aluminum heat exchanger is immersed in a 5 to 40 wt% flatus aqueous solution, thoroughly dried to remove moisture, and then brazed in a heating furnace whose dew point is adjusted to -4°C or lower. A flux brazing method for an aluminum heat exchanger according to item 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9735780A JPS5722870A (en) | 1980-07-16 | 1980-07-16 | Flux brazing method for heat exchanger made of aluminum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9735780A JPS5722870A (en) | 1980-07-16 | 1980-07-16 | Flux brazing method for heat exchanger made of aluminum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5722870A JPS5722870A (en) | 1982-02-05 |
| JPS6342547B2 true JPS6342547B2 (en) | 1988-08-24 |
Family
ID=14190237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9735780A Granted JPS5722870A (en) | 1980-07-16 | 1980-07-16 | Flux brazing method for heat exchanger made of aluminum |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5722870A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0435139U (en) * | 1990-07-18 | 1992-03-24 |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6038663U (en) * | 1983-08-25 | 1985-03-18 | サンデン株式会社 | heat exchanger assembly |
| US4716959A (en) * | 1984-08-27 | 1988-01-05 | Sanden Corporation | Aluminum heat exchangers and method for producing the same |
| JPH0616938B2 (en) * | 1986-04-25 | 1994-03-09 | 三菱アルミニウム株式会社 | Reactive soldering method |
| JP2564190B2 (en) * | 1988-09-12 | 1996-12-18 | 株式会社神戸製鋼所 | Aluminum alloy composite for brazing |
| US7234511B1 (en) * | 1995-06-13 | 2007-06-26 | Philip George Lesage | Modular heat exchanger having a brazed core and method for forming |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5176112A (en) * | 1974-12-27 | 1976-07-01 | Furukawa Aluminium | TAISUIKASEIARUMINIUMUGOKIN |
| JPS5299913A (en) * | 1976-02-18 | 1977-08-22 | Furukawa Aluminium | Production of pendency resisting aluminium alloy sheets |
| JPS54100956A (en) * | 1978-01-25 | 1979-08-09 | Sumitomo Electric Ind Ltd | Aluminum brazing |
| JPS5517072A (en) * | 1978-07-24 | 1980-02-06 | Mitsubishi Keikinzoku Kogyo Kk | Heat exchanger cross fin material |
-
1980
- 1980-07-16 JP JP9735780A patent/JPS5722870A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5176112A (en) * | 1974-12-27 | 1976-07-01 | Furukawa Aluminium | TAISUIKASEIARUMINIUMUGOKIN |
| JPS5299913A (en) * | 1976-02-18 | 1977-08-22 | Furukawa Aluminium | Production of pendency resisting aluminium alloy sheets |
| JPS54100956A (en) * | 1978-01-25 | 1979-08-09 | Sumitomo Electric Ind Ltd | Aluminum brazing |
| JPS5517072A (en) * | 1978-07-24 | 1980-02-06 | Mitsubishi Keikinzoku Kogyo Kk | Heat exchanger cross fin material |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0435139U (en) * | 1990-07-18 | 1992-03-24 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5722870A (en) | 1982-02-05 |
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