CA2118658A1 - Spendable anode for anticorrosion protection of offshore structures, and process for manufacturing it - Google Patents
Spendable anode for anticorrosion protection of offshore structures, and process for manufacturing itInfo
- Publication number
- CA2118658A1 CA2118658A1 CA002118658A CA2118658A CA2118658A1 CA 2118658 A1 CA2118658 A1 CA 2118658A1 CA 002118658 A CA002118658 A CA 002118658A CA 2118658 A CA2118658 A CA 2118658A CA 2118658 A1 CA2118658 A1 CA 2118658A1
- Authority
- CA
- Canada
- Prior art keywords
- anode
- anodic material
- spendable
- anodic
- offshore
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 11
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 5
- 239000010405 anode material Substances 0.000 claims abstract description 33
- 239000011248 coating agent Substances 0.000 claims abstract description 14
- 238000000576 coating method Methods 0.000 claims abstract description 14
- 239000000463 material Substances 0.000 claims abstract description 8
- 238000005266 casting Methods 0.000 claims description 7
- 229910000861 Mg alloy Inorganic materials 0.000 claims description 6
- 229910000838 Al alloy Inorganic materials 0.000 claims description 5
- 229910001297 Zn alloy Inorganic materials 0.000 claims description 5
- 239000002131 composite material Substances 0.000 abstract description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 3
- 239000011701 zinc Substances 0.000 description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 241000370685 Arge Species 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/10—Electrodes characterised by the structure
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
- C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
- C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
- C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
- C23F13/18—Means for supporting electrodes
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
- E02B17/0017—Means for protecting offshore constructions
- E02B17/0026—Means for protecting offshore constructions against corrosion
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F2213/00—Aspects of inhibiting corrosion of metals by anodic or cathodic protection
- C23F2213/30—Anodic or cathodic protection specially adapted for a specific object
- C23F2213/31—Immersed structures, e.g. submarine structures
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Engineering & Computer Science (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Prevention Of Electric Corrosion (AREA)
Abstract
"IMPROVED SPENDABLE ANODE FOR ANTICORROSION PROTECTION
OF OFFSHORE STRUCTURES, AND PROCESS FOR MANUFACTURING
IT".
Abstract A spendable anode for the anticorrosion protection of offshore structures, is constituted by a composite structure in which a first anodic material, which constitutes an external coating on the same anode carrier means, with said material having a more negative electrochemical potential than of the material which constitutes the offshore structure to be protected, is provided, in its turn, with an external coating constituited by a second anodic material the electrochemical potential of which is still more negative than of said first material.
Furthermore, some types of anodic material, as well as a process for manufacturing such a spendable anode are specified.
OF OFFSHORE STRUCTURES, AND PROCESS FOR MANUFACTURING
IT".
Abstract A spendable anode for the anticorrosion protection of offshore structures, is constituted by a composite structure in which a first anodic material, which constitutes an external coating on the same anode carrier means, with said material having a more negative electrochemical potential than of the material which constitutes the offshore structure to be protected, is provided, in its turn, with an external coating constituited by a second anodic material the electrochemical potential of which is still more negative than of said first material.
Furthermore, some types of anodic material, as well as a process for manufacturing such a spendable anode are specified.
Description
rr: ' 21186~8 "I~PROVED SPENDABLE ANODE FOR ANTICORROSION PROTECTION
OF OFFSHORE STRUCTURES, ~ND PROCESS FOR HANUF~CTURING
IT".
The present invention relates to a novel spendabLe anode for the anticorrosion protection of offshore structures, vhich anode, thanks to its particular composite-structure con~iguration, besides making it possible the necessary amount of anodic material to be decreased ~ith self-explanatory economic advantages, also improves the protection state of the surfaces of the offshore structure, ~ith protective compact deposits being formed in a larger amount.
The present invention also relates to the process for acconplishing such a spendable anode.
According to the prior art, the anticorrosion protection of offshore structures by means of spendable anodes represents today one of the most used techniques in this field, and its developme~.t.s.m~d~.it possible optimal anodic material from the vie~points of efficiency and ~eight and cost savings to be found out, such as aluminum, zinc and magnesium alloys.
According to such a technique, the spendable anode, made of an anodic material having a more negative electrochemical potential than of the material ~hich constitutes the offshore structure to be protected, generates a bias ~hich in its turn causes a protection current to be established, ~hich causes protective calcareous deposits to be formed on the same strucuture.
Such a bias clearly is the h;gher, the more negative the electrochemical potentiaL of the anodic material used.
On the other hand, the above said necessary protection current for the adequate protection of the offshore structure depends, besides such marine conditions as temperature, salinity, oxygen content, and so forth, also, and above all, on the surface condit;ons of the offshore structure to be protected, i.e., ~hether calcareous deposits are present or less.
From the above it results hence that during the early steps of the life time of the offshore structure to be protected, during which the protective calcareous deposits have not been adequately formed yet, the need exists for having the maximal protection current, which may then decrease during the subsequent life steps of the structure, as a function of the quality of the calcareous deposit formed during said initial step.
from the above, it derives that an essential element in the design of any spendable anode is the ability of the latter to supply the high demand of starting protection current during the initial step of the life of the offshore structure, besides being capable of preserving the protection state of said structure throughout the subsequent steps of the useful operating life of the latter. Inasmuch as, however, the starting current ~hich a spendable anode is capable of supplying depends, bes~des the marine conditions and its electrochemical potential, also on :, - :- :.- -:.:: ,,, - .. : : : :-, . .. ::. - . .. ..
OF OFFSHORE STRUCTURES, ~ND PROCESS FOR HANUF~CTURING
IT".
The present invention relates to a novel spendabLe anode for the anticorrosion protection of offshore structures, vhich anode, thanks to its particular composite-structure con~iguration, besides making it possible the necessary amount of anodic material to be decreased ~ith self-explanatory economic advantages, also improves the protection state of the surfaces of the offshore structure, ~ith protective compact deposits being formed in a larger amount.
The present invention also relates to the process for acconplishing such a spendable anode.
According to the prior art, the anticorrosion protection of offshore structures by means of spendable anodes represents today one of the most used techniques in this field, and its developme~.t.s.m~d~.it possible optimal anodic material from the vie~points of efficiency and ~eight and cost savings to be found out, such as aluminum, zinc and magnesium alloys.
According to such a technique, the spendable anode, made of an anodic material having a more negative electrochemical potential than of the material ~hich constitutes the offshore structure to be protected, generates a bias ~hich in its turn causes a protection current to be established, ~hich causes protective calcareous deposits to be formed on the same strucuture.
Such a bias clearly is the h;gher, the more negative the electrochemical potentiaL of the anodic material used.
On the other hand, the above said necessary protection current for the adequate protection of the offshore structure depends, besides such marine conditions as temperature, salinity, oxygen content, and so forth, also, and above all, on the surface condit;ons of the offshore structure to be protected, i.e., ~hether calcareous deposits are present or less.
From the above it results hence that during the early steps of the life time of the offshore structure to be protected, during which the protective calcareous deposits have not been adequately formed yet, the need exists for having the maximal protection current, which may then decrease during the subsequent life steps of the structure, as a function of the quality of the calcareous deposit formed during said initial step.
from the above, it derives that an essential element in the design of any spendable anode is the ability of the latter to supply the high demand of starting protection current during the initial step of the life of the offshore structure, besides being capable of preserving the protection state of said structure throughout the subsequent steps of the useful operating life of the latter. Inasmuch as, however, the starting current ~hich a spendable anode is capable of supplying depends, bes~des the marine conditions and its electrochemical potential, also on :, - :- :.- -:.:: ,,, - .. : : : :-, . .. ::. - . .. ..
2~
its surface and, consequently, its geometry, the above said condition practical-y results in that the geometric dimensions and the ~e;ght of the spendable anode have to be determined as a function of the S starting current required by the offshore structure to be protected, and, respectively, of the protection current ~hich must be generated during the subsequent operating steps of the same structure, after the formation of the protective calcareous deposit.
No~, as magnesium and its alloys display the highest negative eLectrochemical potential, one might think that the spendable anode made of magnesium aLloy is the optimal solution for the anticorrosion protection of offshore structures because it, by generating a high bias and, consequently, a high initial anodic current, is capable of suppLying a very effective protection of the above said structure, by causing compact calcareous deposits to be formed, ~hich reduce the magnitude of the required protection current during the subsequent steps of the useful operating life of said structure. Actually, ho~ever, such an anode of magnesium alloy, by displaying a lo~ anodic efficiency, is not capable of covering the ~hole useful operating life of the offshore structure to be protected, unless it is used in such large amounts as to render it economically - unecceptable, o~ing to its large ~eight and high cost.
In fact, the presently most largely used spendable anodes for the protection of offshore structures are aluminum or zinc alloys uhich secure, 2~$~
even uhen small ueight amounts thereof are used, the fulL protection of the structure to be protected throughout the who~e life span thereof, ~ith the demand for a high initial current being satisfied by S suitabLy increasing the geometric size of said anodes.
The purpose of the present invention precisely is of obviating the above said draubacks and hence supply;ng a spendable anode for the anticorrosion protection of offshore structures uhich is capable of 1û supplying the high starting current uhich is initially demanded in order to create an effective protective layer of calcareous deposit on the offshore structure to be protected, although its geometrical dimens;ons are kept small, as uell as of securing the anticorrosion protection throughout the operating life span of the structure, ~ith its weight being anyuay kept small.
The above purpose is substantially achieved by using a composite-structure spendable anode in uhich the anodic material, generally consisting of zinc or aluminum alloys, uhich constitutes an external coating applied onto the carrier uhich supports the same anode, is externally coated, in its turn, by a second anodic material, generally magnesium alloys, having an electrochemical potential still more negative than of the above said zinc or aluminum alloyed-based anodic material.
The advantages displayed by such a composite-structure spendable anode over to the traditional anodes knoun from the prior art substantially derive 21186~8 from the actions of initial bias;ng and of anodic efficiency ~hich a spendable anode should perform being caused no~ to be carried out by two different anodic materia~s, so as to take the maximal advantage from their intrinsic properties.
In fact, in that ~ay, the magnesium aLloy ~h;ch constitutes the outermost coating, ~ith lo~ anodic capacity and high negative electrochemical potential, will operate dur;ng the first step of the useful operating life of the offshore structure to be protected, and hence makes it possible the geometric dimension of the same anode to be reduced, whilst the internal anodic material, constituted by aluminum or zinc alloys, ~hich starts acting only after that all tS of said outermost magnesium coating has been consumed, will operate on surfaces which are already biased and coated by compact calcareous deposits, which hence require low protection current values, with the weight amount of said internaL anodic material, necessary in order to protect the structure during the residual portion of the useful operating life of the latter, being consequently decreased.
Experimental tests demostrated that the use of composite-structure spendable anodes according to the present invention makes it possible a considerably ~arge economing saving, of the order of 20~., to be obtained, as compared to the use of traditional spendable anodes kno~n from the prior art.
Summing-up, the spendable anode for the anticorrosion protection of an offshore structure, 21 186~8 comprising a carrier means provided with an external coating made of an anodic material having a more negative electrochemical potential than of the materiaL which constitutes said offshore strurture to be protected, is characterized, according to the present invention, in that said anodic material is provided, in its turn, with an external coating of a second anodic material with a still more negative electrochemical potential than of the above said anodic material.
Then, according to a preferred feature of the present invention, the process for manufacturing such a spendable anode, suitable for the anti-corrosion protection of offshore structures, comprises the steps of casting said anodic material which constitutes the external coating of the carrier means which supports the same anode into a suitable ingot mould or chill or mould and then casting, into another suitable ingot mould or chill or mould, said second anod;c material around the anode formed during the preceding step.
The invention is better explained now by referring to the accompanying drawing, which displays a preferred embodiment supplied for merely exemplifying, non-limitative purposes, because technical, structural or technological changes may be always supplied without departing from the scope of the present invention. So, for example, rather than by means of sequential steps of casting into ingot moulds or chills or moulds the two anodic materials which coat, in sandwich fashion, the anode carrier means, 7.
the composite-structure anode can also be manufactured by spraying said second anodic material onto said support already coated with the above said anodic materiaL ~ith lower negative electrochemical potential, or coating the Latter with said second anodic material by means of a plating process.
On the other hand, it is evident that all of the above said processes make it possible composite anodes with any cross-section and length features to be manufactured.
In said drawing:
figure 1 shows a perspective view of a spendable anode for the anticorrosion protection of offshore structures, manufactured according to the invention;
Figure 2 displays a longitudinal sectional view made along the middle of the anode of Figure 1;
Figure 3 displays a front sectional view made along section line AA of figure 2.
Referring to the above Figures, w;th the reference numeral 1 the carrier means is indicated of the anode to be manufactured, which carrier means, charged to a suitable ingot mould or chill or mould, not shown in Figure, is provided with an external coating by casting an anodic material 2 with a more negative electrochemical potential than of the material which constitutes the structure to be protected.
Said coated carrier means is then charged to another suitable ingot mould or chill or mould, also not displayed in Figure, and, in its turn, is provided 21186~
~ith an externa~ coating by casting an anodic material 3 ~ith a more negative e~ectrochemical potential than of the anodic materiaL 2.
its surface and, consequently, its geometry, the above said condition practical-y results in that the geometric dimensions and the ~e;ght of the spendable anode have to be determined as a function of the S starting current required by the offshore structure to be protected, and, respectively, of the protection current ~hich must be generated during the subsequent operating steps of the same structure, after the formation of the protective calcareous deposit.
No~, as magnesium and its alloys display the highest negative eLectrochemical potential, one might think that the spendable anode made of magnesium aLloy is the optimal solution for the anticorrosion protection of offshore structures because it, by generating a high bias and, consequently, a high initial anodic current, is capable of suppLying a very effective protection of the above said structure, by causing compact calcareous deposits to be formed, ~hich reduce the magnitude of the required protection current during the subsequent steps of the useful operating life of said structure. Actually, ho~ever, such an anode of magnesium alloy, by displaying a lo~ anodic efficiency, is not capable of covering the ~hole useful operating life of the offshore structure to be protected, unless it is used in such large amounts as to render it economically - unecceptable, o~ing to its large ~eight and high cost.
In fact, the presently most largely used spendable anodes for the protection of offshore structures are aluminum or zinc alloys uhich secure, 2~$~
even uhen small ueight amounts thereof are used, the fulL protection of the structure to be protected throughout the who~e life span thereof, ~ith the demand for a high initial current being satisfied by S suitabLy increasing the geometric size of said anodes.
The purpose of the present invention precisely is of obviating the above said draubacks and hence supply;ng a spendable anode for the anticorrosion protection of offshore structures uhich is capable of 1û supplying the high starting current uhich is initially demanded in order to create an effective protective layer of calcareous deposit on the offshore structure to be protected, although its geometrical dimens;ons are kept small, as uell as of securing the anticorrosion protection throughout the operating life span of the structure, ~ith its weight being anyuay kept small.
The above purpose is substantially achieved by using a composite-structure spendable anode in uhich the anodic material, generally consisting of zinc or aluminum alloys, uhich constitutes an external coating applied onto the carrier uhich supports the same anode, is externally coated, in its turn, by a second anodic material, generally magnesium alloys, having an electrochemical potential still more negative than of the above said zinc or aluminum alloyed-based anodic material.
The advantages displayed by such a composite-structure spendable anode over to the traditional anodes knoun from the prior art substantially derive 21186~8 from the actions of initial bias;ng and of anodic efficiency ~hich a spendable anode should perform being caused no~ to be carried out by two different anodic materia~s, so as to take the maximal advantage from their intrinsic properties.
In fact, in that ~ay, the magnesium aLloy ~h;ch constitutes the outermost coating, ~ith lo~ anodic capacity and high negative electrochemical potential, will operate dur;ng the first step of the useful operating life of the offshore structure to be protected, and hence makes it possible the geometric dimension of the same anode to be reduced, whilst the internal anodic material, constituted by aluminum or zinc alloys, ~hich starts acting only after that all tS of said outermost magnesium coating has been consumed, will operate on surfaces which are already biased and coated by compact calcareous deposits, which hence require low protection current values, with the weight amount of said internaL anodic material, necessary in order to protect the structure during the residual portion of the useful operating life of the latter, being consequently decreased.
Experimental tests demostrated that the use of composite-structure spendable anodes according to the present invention makes it possible a considerably ~arge economing saving, of the order of 20~., to be obtained, as compared to the use of traditional spendable anodes kno~n from the prior art.
Summing-up, the spendable anode for the anticorrosion protection of an offshore structure, 21 186~8 comprising a carrier means provided with an external coating made of an anodic material having a more negative electrochemical potential than of the materiaL which constitutes said offshore strurture to be protected, is characterized, according to the present invention, in that said anodic material is provided, in its turn, with an external coating of a second anodic material with a still more negative electrochemical potential than of the above said anodic material.
Then, according to a preferred feature of the present invention, the process for manufacturing such a spendable anode, suitable for the anti-corrosion protection of offshore structures, comprises the steps of casting said anodic material which constitutes the external coating of the carrier means which supports the same anode into a suitable ingot mould or chill or mould and then casting, into another suitable ingot mould or chill or mould, said second anod;c material around the anode formed during the preceding step.
The invention is better explained now by referring to the accompanying drawing, which displays a preferred embodiment supplied for merely exemplifying, non-limitative purposes, because technical, structural or technological changes may be always supplied without departing from the scope of the present invention. So, for example, rather than by means of sequential steps of casting into ingot moulds or chills or moulds the two anodic materials which coat, in sandwich fashion, the anode carrier means, 7.
the composite-structure anode can also be manufactured by spraying said second anodic material onto said support already coated with the above said anodic materiaL ~ith lower negative electrochemical potential, or coating the Latter with said second anodic material by means of a plating process.
On the other hand, it is evident that all of the above said processes make it possible composite anodes with any cross-section and length features to be manufactured.
In said drawing:
figure 1 shows a perspective view of a spendable anode for the anticorrosion protection of offshore structures, manufactured according to the invention;
Figure 2 displays a longitudinal sectional view made along the middle of the anode of Figure 1;
Figure 3 displays a front sectional view made along section line AA of figure 2.
Referring to the above Figures, w;th the reference numeral 1 the carrier means is indicated of the anode to be manufactured, which carrier means, charged to a suitable ingot mould or chill or mould, not shown in Figure, is provided with an external coating by casting an anodic material 2 with a more negative electrochemical potential than of the material which constitutes the structure to be protected.
Said coated carrier means is then charged to another suitable ingot mould or chill or mould, also not displayed in Figure, and, in its turn, is provided 21186~
~ith an externa~ coating by casting an anodic material 3 ~ith a more negative e~ectrochemical potential than of the anodic materiaL 2.
Claims (5)
1. Spendable anode for the anticorrosion protection of an offshore structure, comprising a carrier means provided with an external coating made of an anodic material having a more negative electrochemical potential than of the material which constitutes said offshore structure to be protected, characterized, in that said anodic material is provided, in its turn, with an external coating made of a second anodic material with a still more negative electrochemical potential than of the above said anodic material.
2. Spendable anode according to Claim 1, characterized in that said anodic material which externally coats said carrier means is constituted by aluminum alloys.
3. Spendable anode according to Claim 1, characterized in that said anodic material which externally coats said carrier means is constituted by zinc alloys.
4. Spendable anode according to Claim 1, characterized in that said second anodic material is constituted by magnesium alloys.
5. Process for manufacturing a spendable anode suitable for the anticorrosion protection of offshore structures, according to the preceding claims, characterized in that it comprises the steps of casting said anodic material which constitutes the external coating of the carrier means of the same anode into a suitable ingot mould or chill or mould 10.
and then casting, into another suitable ingot mould or chill or mould, said second anodic material around the anode formed during the preceding step.
and then casting, into another suitable ingot mould or chill or mould, said second anodic material around the anode formed during the preceding step.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ITMI93A000457 | 1993-03-10 | ||
| ITMI930457A IT1272001B (en) | 1993-03-10 | 1993-03-10 | PERFECTED SACRIFICIAL ANODE FOR THE ANTI-CORROSIVE PROTECTION OF OFFSHORE STRUCTURES AND PROCEDURE FOR ITS CONSTRUCTION. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2118658A1 true CA2118658A1 (en) | 1994-09-11 |
Family
ID=11365307
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002118658A Abandoned CA2118658A1 (en) | 1993-03-10 | 1994-03-09 | Spendable anode for anticorrosion protection of offshore structures, and process for manufacturing it |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0615002A1 (en) |
| JP (1) | JPH06340986A (en) |
| CN (1) | CN1107534A (en) |
| BR (1) | BR9400848A (en) |
| CA (1) | CA2118658A1 (en) |
| IT (1) | IT1272001B (en) |
| NO (1) | NO940787L (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6461082B1 (en) * | 2000-08-22 | 2002-10-08 | Exxonmobil Upstream Research Company | Anode system and method for offshore cathodic protection |
| JP5167863B2 (en) * | 2008-02-28 | 2013-03-21 | 株式会社Ｉｈｉ | Anode for forming anticorrosion electrodeposition coating on steel structure |
| CN102328064A (en) * | 2011-03-11 | 2012-01-25 | 中国海洋石油总公司 | Magnalium composite sacrificial anode and preparation method thereof |
| CN102328063A (en) * | 2011-03-11 | 2012-01-25 | 中国海洋石油总公司 | Magnalium composite sacrificial anode and preparation method thereof |
| JP6333248B2 (en) * | 2012-07-30 | 2018-05-30 | コンストラクション リサーチ アンド テクノロジー ゲーエムベーハーＣｏｎｓｔｒｕｃｔｉｏｎ Ｒｅｓｅａｒｃｈ ＆ Ｔｅｃｈｎｏｌｏｇｙ ＧｍｂＨ | Electrostatic anode and corrosion prevention method |
| CA3152509A1 (en) * | 2012-10-18 | 2014-04-24 | Gareth Glass | Protection of steel reinforced concrete elements |
| CN113122852A (en) * | 2021-04-25 | 2021-07-16 | 浙江钰烯腐蚀控制股份有限公司 | Preparation method of magnesium-aluminum composite anode and magnesium-aluminum composite anode |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1803523B1 (en) * | 1968-10-17 | 1970-03-05 | Stein Dr Ing Heinrich | Process for the production of sacrificial anodes for cathodic protection against corrosion |
| CH540351A (en) * | 1971-04-27 | 1973-08-15 | Alusuisse | Sacrificial anode |
| FR2364274A1 (en) * | 1976-09-13 | 1978-04-07 | Elf Aquitaine | CATHODIC PROTECTION OF A STRUCTURE AT SEA BY SACRIFICIAL ANODES |
| US4409081A (en) * | 1982-02-05 | 1983-10-11 | Terrase Leon J | Sacrificial anode |
| DK12989D0 (en) * | 1989-01-11 | 1989-01-11 | Joergen Hoegberg | HOLDER FOR SHIPPING ANODS |
-
1993
- 1993-03-10 IT ITMI930457A patent/IT1272001B/en active IP Right Grant
-
1994
- 1994-03-05 EP EP94200566A patent/EP0615002A1/en not_active Withdrawn
- 1994-03-07 NO NO940787A patent/NO940787L/en unknown
- 1994-03-09 BR BR9400848A patent/BR9400848A/en not_active Application Discontinuation
- 1994-03-09 CA CA002118658A patent/CA2118658A1/en not_active Abandoned
- 1994-03-10 JP JP6066643A patent/JPH06340986A/en not_active Withdrawn
- 1994-03-10 CN CN94104277A patent/CN1107534A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| IT1272001B (en) | 1997-06-10 |
| BR9400848A (en) | 1994-11-08 |
| CN1107534A (en) | 1995-08-30 |
| EP0615002A1 (en) | 1994-09-14 |
| JPH06340986A (en) | 1994-12-13 |
| NO940787D0 (en) | 1994-03-07 |
| ITMI930457A0 (en) | 1993-03-10 |
| ITMI930457A1 (en) | 1994-09-10 |
| NO940787L (en) | 1994-09-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |