JPH0368943B2 - - Google Patents
Info
- Publication number
- JPH0368943B2 JPH0368943B2 JP59102435A JP10243584A JPH0368943B2 JP H0368943 B2 JPH0368943 B2 JP H0368943B2 JP 59102435 A JP59102435 A JP 59102435A JP 10243584 A JP10243584 A JP 10243584A JP H0368943 B2 JPH0368943 B2 JP H0368943B2
- Authority
- JP
- Japan
- Prior art keywords
- amount
- alloy
- anode
- aluminum
- silicon
- 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 - Lifetime
Links
- 229910052710 silicon Inorganic materials 0.000 claims description 13
- 239000010703 silicon Substances 0.000 claims description 13
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 12
- 229910052788 barium Inorganic materials 0.000 claims description 12
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 claims description 12
- 229910052791 calcium Inorganic materials 0.000 claims description 12
- 239000011575 calcium Substances 0.000 claims description 12
- 229910052738 indium Inorganic materials 0.000 claims description 11
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 11
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 10
- 229910052725 zinc Inorganic materials 0.000 claims description 10
- 239000011701 zinc Substances 0.000 claims description 10
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 9
- 229910052782 aluminium Inorganic materials 0.000 claims description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 9
- 229910052749 magnesium Inorganic materials 0.000 claims description 9
- 239000011777 magnesium Substances 0.000 claims description 9
- 229910000838 Al alloy Inorganic materials 0.000 claims description 7
- 229910045601 alloy Inorganic materials 0.000 description 23
- 239000000956 alloy Substances 0.000 description 23
- 230000005611 electricity Effects 0.000 description 18
- 230000000694 effects Effects 0.000 description 14
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 11
- 238000004090 dissolution Methods 0.000 description 10
- 239000000203 mixture Substances 0.000 description 6
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 3
- 238000004210 cathodic protection Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 239000013535 sea water Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000002301 combined effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- ZOMNIUBKTOKEHS-UHFFFAOYSA-L dimercury dichloride Chemical class Cl[Hg][Hg]Cl ZOMNIUBKTOKEHS-UHFFFAOYSA-L 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000007970 homogeneous dispersion Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Landscapes
- Prevention Of Electric Corrosion (AREA)
Description
本発明は海水、淡水、土壌中等、各種環境中の
施設、船舶、機器などの陰極防食に使用する流電
陽極用アルミニウム合金に関する。
アルミニウムは本来、単位重量当りの発生電気
量が大きく、現用の流電陽極系基金属としてはマ
グネシウム、亜鉛などに比べて最も有用である。
また防食電流発生の駆動力となる電極電位も本来
は極めて卑であるが通常は安定した酸化皮膜で表
面が覆われ、鉄鋼よりやや卑な電位を有するにす
ぎず、純アルミニウムでは紡食能力を期待するこ
とは困難である。そのため従来から種々の他元素
を添加して合金化による陽極性能改善の試みが行
なわれている。
本出願人らはアルミニウムに亜鉛とインジウム
を含有させた合金をベースにして一連の研究開発
を継続してきた。その結果、さきに亜鉛1.0〜10
％、インジウム0.01〜0.05％、マグネシウム0.05
〜６％を含有する合金を開発し、特許を得た（特
公昭42−14291）。この合金の陽極性能は陽極電位
がいずれも−1080〜−1100ｍＶ（飽和カロメル電
極基準）の値を示し、発生電気量としては2400〜
2600Ahr／Kg程度の能力を有し、マグネシウムの
少量添加によりインジウムの均一分散を図り陽極
性能を向上せしめたものであつた。しかし、この
合金陽極はなお発生電気量が十分とはいえず、若
干の課題を残すものであつた。
その後、本発明者らはさらに検討を重ねる過程
において、前記合金陽極に珪素と、カルシウムお
よびバリウムの１種または２種と所定量含有せし
めることにより従来合金のいずれよりも高い
2700Ahr／Kg以上の発生電気量を、またある特定
の組成においては2800Ahr／Kg以上の発生電気量
を発揮する合金を見出すに至つた。
本発明合金は前記従来合金において示された陽
極効率84〜90％、すなわち発生電気量に換算して
約2440〜2600Ahr／Kgを明らかに大幅にしのぐ発
生電気量を有するものであつて、その成分組成は
亜鉛1.0〜10％、インジウム0.01〜0.05％、マグネ
シウム0.05〜６％を含有する流電陽極用アルミニ
ウム合金において、これに珪素0.07〜1.0％、カ
ルシウムとバリウムの１種または２種を0.01〜
0.5％含有し、残部アルミニウムよりなることを
特徴とする流電陽極用アルミニウム合金である。
本発明の基材となる、亜鉛1.0〜10％、マグネ
シウム0.05〜６％、インジウム0.01〜0.05％を含
有する合金は、本出願人が先に発明した流電陽極
合金である。各元素の効果と含有量は次の通りで
ある。亜鉛は陽極電位の安定化、自己腐食の抑制
及びインジウムがアルミニウム中へ均一に分散さ
せることを目的とする。１％より少量では、これ
らの効果は小であり、特にインジウムの均一分散
作用が不充分である。また10％を超えると鋳造性
に難点があり、特に亜鉛の量が多くなると発生電
気量の増大が期待できない。従つて、1.0〜10％
が適正である。マグネシウムは陽極電位、発生電
気量の改善に有効であり、インジウムの分散性を
改善する。0.05％より少量では効果が乏しく、６
％を超えると性能が低下する。従つて、0.05〜６
％が適正である。インジウムはアルミニウム合金
を活性化させる効果を有するが、高価な金属であ
るため添加量は極力抑えなければならない。しか
し、0.01％より少量ではアルミニウム中への均一
分散が亜鉛やマグネシウムを併用しても局部溶解
になり易く、また0.05％を超えると添加効果が飽
和に達し、経済的に不利である。従つて、0.01〜
0.05％が適正である。
次に本願発明の流電陽極用アルミニウム合金に
おいて、珪素、カルシウムおよびバリウムの成分
組成の範囲を上述のように限定した理由を説明す
る。
珪素は溶解面の改善に著しい効果を示す。すな
わち溶解面の緻密化、均一化、全面化は発生電気
量の増加に大きく寄与し、優れた溶解挙動は合金
の無用な自己腐食を抑制し、実用に際しては長期
耐用につながるものである。本発明合金において
は0.07％以上の含有で上記の特徴を発揮するが、
最大1.0％を越えると溶解面に不同、局部化が認
められ、陽極電位も若干の貴化をまぬがれないの
で有効含有量を0.07〜10％と定めた。
カルシウムの添加は珪素との併用において溶解
特性と発生電気量増大の両面に著しい効果を示
す。この場合カルシウムの含有量が0.01％に満た
ないときは特性改善の効果が少く、また0.5％を
越えるとむしろ溶解面に不同、局部化傾向が表わ
れ、安定性が失われる。この珪素含有量は前記
0.07〜1.0％のうち0.15％を越える範囲が好まし
く、とくに0.2％を越える範囲が最も顕著な効果
を示す。
バリウムもカルシウムと同様の添加効果を有
し、珪素との有効な含有量の共存で併用相乗効果
が顕著である。すなわちバリウム0.01〜0.5％を
上記珪素0.07〜1.0％と併用させると陽極の溶解
挙動の不同、不規則が是正され、溶解面の孔食が
消滅し、局部的溶解が生じない効果を示す。この
溶解面の改善は発生電気量の増大をもたらす。こ
のバリウムの添加効果は上記0.01〜0.5％の含有
範囲が適量で0.01％に満たないときは溶解の均一
化が損われ、また0.5％を越えると溶解面が局部
化しやすく、かつ粗面となり、発生電気量も低下
する。
またバリウムとカルシウムの共存においてさら
に珪素と併用するときはなお一層高い発生電気量
を廃棄し、その含有量は前記バリウムおよびカル
シウムのそれぞれ単独の含有量を軽減することが
できる。すなわち、前記の珪素量0.07〜1.0％が
含有されているときカルシウムとバリウムが各々
0.005〜0.3％の範囲内で同時にしかもその合計量
が0.01〜0.5％含有されるとき前記効果を最も顕
著に発揮し、この範囲より少ないときは発生電気
量増大の効果は少なく、またこの範囲を越えると
きは発生電気量も低下し、陽極電位にも悪影響を
与える。
以上のような本発明では珪素とカルシウムおよ
びバリウムの１種または２種との併用効果を意図
することが大きな特徴となるものであり、これに
より溶解特性の向上を発生電気量の著しい増大が
もたらされる。
次に本発明合金の実施例について説明する。
実施例 １
表１及び表２に示す組成を有する本発明合金お
よび比較合金を直径20mm、長さ120mmの丸棒に金
型鋳造し、側面の20cm2を陽極部として供試し、
1.5の室温の人工海水静止液中において陽極電
流密度1.0ｍＡ／cm2で240時間通電する定電流ビー
カーテストを行つた。その結果は表１に示すよう
に本発明合金が発生電気量において著しく優れて
いることが明白で、亜鉛、マグネシウム、インジ
ウム、珪素の最適量を含有し、さらにカルシウム
およびバリウムの１種または２種を適量併合し、
残部アルミニウムからなる合金系は2700Ahr／Kg
以上の極めて優れた特性を発揮している。すなわ
ち比較合金の発生電気量が2520Ahr／Kgであるの
に対し、本発明合金はいずれも2700Ahr／Kg以上
を示し、そのうちの特に有効な組成では
2800Ahr／Kg以上を示し陽極電位も充分卑な値を
有している。
以上のように本発明合金は従来合金にみられな
い高い発生電気量を有し、長期間安定して使用す
るに充分な特性を備えており、大型構造物の長期
電気防食におけるメンテナンスフリー化に極めて
有利、有用な流電陽極合金である。
The present invention relates to an aluminum alloy for galvanic anodes used for cathodic protection of facilities, ships, equipment, etc. in various environments such as seawater, freshwater, and soil. Aluminum inherently generates a large amount of electricity per unit weight, and is the most useful base metal for current galvanic anode systems compared to magnesium, zinc, etc.
In addition, the electrode potential, which is the driving force for generating anticorrosion current, is originally extremely base, but the surface is usually covered with a stable oxide film, and has a slightly lower potential than steel, and pure aluminum has poor spinning ability. It is difficult to expect. Therefore, attempts have been made heretofore to improve anode performance by adding various other elements and forming alloys. The present applicants have continued a series of research and development activities based on an alloy of aluminum containing zinc and indium. As a result, zinc 1.0-10
%, indium 0.01-0.05%, magnesium 0.05
An alloy containing ~6% was developed and patented (Japanese Patent Publication No. 14291, 1973). The anode performance of this alloy shows that the anode potential is -1080 to -1100mV (based on saturated calomel electrode), and the amount of electricity generated is 2400 to -1100mV.
It had a capacity of about 2600Ahr/Kg, and the anode performance was improved by adding a small amount of magnesium to uniformly disperse indium. However, the amount of electricity generated by this alloy anode was still not sufficient, and some problems remained. After that, in the process of further investigation, the present inventors found that by making the alloy anode contain a predetermined amount of silicon and one or both of calcium and barium, the
We have discovered an alloy that can generate more than 2,700 Ahr/Kg, and in a specific composition, can generate more than 2,800 Ahr/Kg. The alloy of the present invention has an anode efficiency of 84 to 90%, that is, the amount of electricity generated that clearly exceeds the amount of electricity shown in the conventional alloy, which is approximately 2440 to 2600 Ahr/Kg, and its composition The composition is an aluminum alloy for galvanic anodes containing 1.0 to 10% zinc, 0.01 to 0.05% indium, and 0.05 to 6% magnesium, with 0.07 to 1.0% silicon and 0.01 to 10% of one or both of calcium and barium.
This is an aluminum alloy for galvanic anodes, characterized in that it contains 0.5% aluminum with the remainder being aluminum. The alloy containing 1.0 to 10% zinc, 0.05 to 6% magnesium, and 0.01 to 0.05% indium, which is the base material of the present invention, is a galvanic anode alloy previously invented by the applicant. The effects and contents of each element are as follows. The purpose of zinc is to stabilize the anode potential, suppress self-corrosion, and uniformly disperse indium into aluminum. If the amount is less than 1%, these effects are small, and in particular, the effect of uniformly dispersing indium is insufficient. Moreover, if it exceeds 10%, there will be a problem in castability, and in particular, if the amount of zinc is large, an increase in the amount of electricity generated cannot be expected. Therefore, 1.0-10%
is appropriate. Magnesium is effective in improving the anode potential and the amount of electricity generated, and improves the dispersibility of indium. If the amount is less than 0.05%, the effect is poor; 6
If it exceeds %, performance will deteriorate. Therefore, 0.05~6
% is appropriate. Indium has the effect of activating aluminum alloys, but since it is an expensive metal, the amount added must be kept as low as possible. However, if the amount is less than 0.01%, homogeneous dispersion in aluminum tends to result in local dissolution even when zinc or magnesium is used in combination, and if it exceeds 0.05%, the effect of addition reaches saturation, which is economically disadvantageous. Therefore, 0.01~
0.05% is appropriate. Next, the reason why the ranges of the compositions of silicon, calcium and barium in the aluminum alloy for galvanic anodes of the present invention are limited as described above will be explained. Silicon has a remarkable effect on improving the melting surface. In other words, densification, uniformity, and fullness of the melting surface greatly contribute to increasing the amount of electricity generated, and excellent melting behavior suppresses unnecessary self-corrosion of the alloy, leading to long-term durability in practical use. The alloy of the present invention exhibits the above characteristics when the content is 0.07% or more, but
If the content exceeds the maximum of 1.0%, unevenness and localization will be observed on the dissolution surface, and the anode potential will inevitably become slightly noble, so the effective content was set at 0.07 to 10%. Addition of calcium, when used in combination with silicon, has a remarkable effect on both dissolution properties and increase in the amount of electricity generated. In this case, when the calcium content is less than 0.01%, the effect of improving properties is small, and when it exceeds 0.5%, the dissolution surface tends to be uneven and localized, resulting in loss of stability. This silicon content is
Among 0.07 to 1.0%, a range exceeding 0.15% is preferable, and a range exceeding 0.2% shows the most remarkable effect. Barium also has the same additive effect as calcium, and has a remarkable synergistic effect when combined with silicon in an effective amount. That is, when 0.01 to 0.5% barium is used in combination with 0.07 to 1.0% silicon, unevenness and irregularity in the dissolution behavior of the anode are corrected, pitting corrosion on the dissolution surface disappears, and local dissolution does not occur. This improvement in the melting surface results in an increase in the amount of electricity generated. The effect of adding barium is that the content range of 0.01 to 0.5% is appropriate; if it is less than 0.01%, the uniformity of dissolution is impaired, and if it exceeds 0.5%, the dissolution surface tends to be localized and becomes rough. The amount of electricity generated also decreases. Furthermore, when barium and calcium coexist, when they are used in combination with silicon, an even higher amount of generated electricity is discarded, and the content thereof can be reduced compared to the respective individual contents of barium and calcium. That is, when the above silicon content is 0.07 to 1.0%, calcium and barium are each
When the content is within the range of 0.005 to 0.3% and the total amount is 0.01 to 0.5%, the above effect is most pronounced; when it is less than this range, the effect of increasing the amount of electricity generated is small; If it exceeds the limit, the amount of electricity generated will also decrease, and the anode potential will also be adversely affected. A major feature of the present invention as described above is that it is intended to have a combined effect of silicon and one or both of calcium and barium, which results in improved dissolution characteristics and a significant increase in the amount of electricity generated. It will be done. Next, examples of the alloy of the present invention will be described. Example 1 The alloy of the present invention and the comparative alloy having the compositions shown in Tables 1 and 2 were mold-cast into round bars with a diameter of 20 mm and a length of 120 mm, and 20 cm 2 of the side surface was used as an anode part.
A constant current beaker test was conducted in which a current was applied for 240 hours at an anode current density of 1.0 mA/cm 2 in a static artificial seawater solution at room temperature of 1.5 mA. As shown in Table 1, the results clearly show that the alloy of the present invention is significantly superior in the amount of electricity generated, contains optimal amounts of zinc, magnesium, indium, and silicon, and also contains one or two of calcium and barium. Combine an appropriate amount of
Alloy system consisting of balance aluminum is 2700Ahr/Kg
It exhibits the extremely excellent characteristics mentioned above. In other words, while the comparative alloy generated electricity was 2520Ahr/Kg, the invention alloys all showed more than 2700Ahr/Kg, and among them, the particularly effective composition
It shows 2800Ahr/Kg or more, and the anode potential also has a sufficiently base value. As described above, the alloy of the present invention has a high amount of electricity generated that is not seen in conventional alloys, has sufficient characteristics for stable use over a long period of time, and is suitable for maintenance-free long-term cathodic protection of large structures. It is a highly advantageous and useful galvanic anode alloy.
【表】【table】
【表】【table】
【表】【table】
Claims (1)
グネシウム0.05〜６％を含有する流電陽極用アル
ミニウム合金において、さらに珪素0.07〜1.0％、
カルシウムおよびバリウムの１種または２種0.01
〜0.5％を含有し、残部アルミニウムからなる流
電陽極用アルミニウム合金。1 In an aluminum alloy for galvanic anodes containing 1.0 to 10% zinc, 0.01 to 0.05% indium, and 0.05 to 6% magnesium, further containing 0.07 to 1.0% silicon,
One or two types of calcium and barium 0.01
An aluminum alloy for galvanic anodes containing ~0.5% and the remainder aluminum.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59102435A JPS60245766A (en) | 1984-05-21 | 1984-05-21 | Aluminum alloy for sacrificial anode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59102435A JPS60245766A (en) | 1984-05-21 | 1984-05-21 | Aluminum alloy for sacrificial anode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60245766A JPS60245766A (en) | 1985-12-05 |
| JPH0368943B2 true JPH0368943B2 (en) | 1991-10-30 |
Family
ID=14327385
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59102435A Granted JPS60245766A (en) | 1984-05-21 | 1984-05-21 | Aluminum alloy for sacrificial anode |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60245766A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2924609B2 (en) * | 1993-10-26 | 1999-07-26 | 日本軽金属株式会社 | Aluminum alloy for corrosion protection of steel structures |
| CN105648445A (en) * | 2016-01-07 | 2016-06-08 | 广西大学 | Aluminum-zinc-indium-erbium sacrificial anode and preparation method thereof |
-
1984
- 1984-05-21 JP JP59102435A patent/JPS60245766A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60245766A (en) | 1985-12-05 |
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