CA2567681A1 - Alloy for use in galvanic protection - Google Patents

Alloy for use in galvanic protection Download PDF

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Publication number
CA2567681A1
CA2567681A1 CA002567681A CA2567681A CA2567681A1 CA 2567681 A1 CA2567681 A1 CA 2567681A1 CA 002567681 A CA002567681 A CA 002567681A CA 2567681 A CA2567681 A CA 2567681A CA 2567681 A1 CA2567681 A1 CA 2567681A1
Authority
CA
Canada
Prior art keywords
per cent
anode
minus
plus
cathode
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
Application number
CA002567681A
Other languages
French (fr)
Inventor
Brett Alexander Maddern
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MARINE PROTECTION SYSTEMS Pty Ltd
Original Assignee
MARINA PROTECTION SYSTEMS Pty Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by MARINA PROTECTION SYSTEMS Pty Ltd filed Critical MARINA PROTECTION SYSTEMS Pty Ltd
Publication of CA2567681A1 publication Critical patent/CA2567681A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C21/00Alloys based on aluminium
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23FNON-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
    • C23F13/00Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/06Constructional parts, or assemblies of cathodic-protection apparatus
    • C23F13/08Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
    • C23F13/12Electrodes characterised by the material
    • C23F13/14Material for sacrificial anodes
    • CCHEMISTRY; METALLURGY
    • C23COATING 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
    • C23FNON-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
    • C23F2213/00Aspects of inhibiting corrosion of metals by anodic or cathodic protection
    • C23F2213/30Anodic or cathodic protection specially adapted for a specific object
    • C23F2213/31Immersed structures, e.g. submarine structures

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Prevention Of Electric Corrosion (AREA)

Abstract

The invention relates to an aluminium alloy and anode made therefrom containing silicon, iron, copper, manganese, magnesium, chromium, zinc and titanium. The anode is used as a sacrificial anode in water vessels with non-metallic hulls.

Description

TITLE
"ALLOY FOR USE IN GALVANIC PROTECTION"
FIELD OF THE YNVENTION

The present invention relates to an alloy used in the galvanic protection of non metallic water vessels.

BACKGROUND TO THE INVEN'TION

In the marine industry the prevention of corrosion of components, such as metal fasteners, shaft and propeller components, constructed from stainless steel and bronze alloys is a primazy concern. In aerated marine environments these materials are susceptible to crevice and pitting corrosion. Sacrificial anodes are commonly employed to provide cathodic protection to these components. Application of these sacrificial anodes on wooden and fibreglass vessels can result in an over protection, which may result in a reduced life of coatings and an enhanced level of marine growth and wood rot.

The present invention seeks, therefore, among other things, to provide an alloy which overcomes some of the above mentioned disadvantages.

SiJMMARY OF THE INVENTION

An alloy which comprises from 0.30 to 0.6 per cent silicon plus or minus 5 per cent, 0. l to 0.30 per cent iron plus or minus 5 per cent, 0.10 copper plus or minus 5 per cent, 0,10 per cent manganese plus or minus 5 per cent, 0.35 to 0.6 per cent magnesium plus or minus 5 per cent, 0.05 per cent chromium plus or minus 5 per cent, 0.15 per cent zinc plus or minus 5 per cent, 0.10 per cent titanium plus or minus 5 per cent, 0.05 maximum
2 individual trace metals plus or minus 5 per cent, 0. 15 per cent total trace metals plus or minus 5 per cent and the balance aluminium.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing there is shown Figure 1 which is a schematic side elevation of an anode formed of the alloy of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In, a preferred embodiment of the present invention the metallic components of a water vessel with a non-metallic hull are protected by connecting the alloy of the present invention and the metallic components of the water vessel to form an electrochemical cell. This electrochemical cell is created through the electrical connection of an anode formed of the alloy the present invention to a cathode which are the metallic components of a vessel. The cathode and the anode are both located in a bridging medium.
The connection of the anode and the cathode in this way allows for the passage of electrons from the anode to the cathode. These electrons are generated through oxidation of species at the anode and reduction of species at the cathode.

In a galvanic protection system the physical integrity of the anode is sacrificed in orderto maintain the physical integrity of the cathode. The physical integrity of the anode is sacrificed through the dissolution of the anode into the bridging medium. The suitability of the anode for galvanic protection is determined by the electrochemical potential ofthe anode compared to the cathode and the capacity of the anode to protect the oathode.
3 The alloy forming the anode has a chemical composition comprising 0.30 to 0.6 per cent silicon plus or minus 5 per cent, 0.1 to 0.30 per cent iron plus or minus 5 per cent, 0.10 copper plus or minus 5 per cent, 0.10 per cent manganese plus or minus 5 per cent, 0.35 to 0.6 per cent magnesium plus or minus 5 per cent, 0.05 per cent chromium plus or minus 5 per cent, 0.15 per cetnt zinc plus or minus 5 per cent, 0.10 per cent titanium plus or minus S per cent, 0.05 maximum in.dividual trace metals plus or minus 5 per cent, 0.15 per cent total trace metals plus or minus 5 per cent with the balance being aluminium.
The anode forrned of the alloy of the present invention has an electrochemical potential more negative than that of the cathode, preferably with an electrochemical potential in the range of -500 to -1200 mV, more preferably with an electrochemical potential in the range of -500 to -1100 mV.

The capacity of the anode to protect the cathode may be in the range of 1000 to 2000 At/kg, preferably in the range of 1400 to 1700 Ah/kg.

The surface area of the anode 10 shown in Figure 1 is increased through the incorporation of ridges 12 on the surface of the anode. The surface area ratio of the anode to the cathode may be in the range of 1:1 to 1:20, preferably in the range of 1;2 to 1:20.

The electrical connection provides a passage for the flow of electrons between the cathode and the anode. The electrical connection is preferably a metallic wire, more preferably a copper wire.
4 The bridging medium provides a passage for the flow of electrons between the anode and the cathode. The bridging medium is preferably an aqueous solution, more preferably saltwater, particularly sea water.

s By applying an excess negative electcochemical potential applied across the cell the accumulation of excess calcium deposits, wood rot and paint disbondment may be prevented. This excess negative electrochemical potential is applied across the cell due to the differences in the electrochemical potential of the anode and the cathode.

In an alternative embodiment of the invention, seawater as a bridging medium may be replaced with another suitable aqueous liquid, preferably brackish water or fresh water.
The anode may be connected to the metallic components of the vessel using known techniques such as connecting the anode to the shaft gland/ seal and, or shaft support bracket and, or the rudder and, or the trimtabs through a bonding buss bar/
system via bonding wire, The anode of the present invention is particularly envisaged for use with water vessels with fibreglass or wooden hulls.

Modifications or variations as would be apparent to a slcilled addressee are deemed to be within the scope of the present invention.
5

Claims (12)

1. An alloy which comprises from 0.30 to 0.6 per cent silicon plus or minus 5 per cent, 0.1 to 0.30 per cent iron plus or minus 5 per cent, 0.10 copper plus or minus 5 per cent, 0.10 per cent manganese plus or minus 5 per cent, 0.35 to 0,6 per cent magnesium plus or minus 5 per cent, 0.05 per cent chromium plus or minus 5 per cent, 0.15 per cent zinc plus or minus 5 per cent, 0.10 per cent titanium plus or minus 5 per cent, 0.05 maximum individual trace metals plus or minus 5 per cent, 0.15 per cent total trace metals plus or minus 5 per cent and the balance aluminium.
2. An anode formed of an alloy according to claim 1.
3. An anode as according to claim 2, wherein the electrochemical potential of the anode is more negative than that of the cathode.
4. An anode as according to claim 3, wherein the electrochemical potential of the anode is in the range of -500 to -1200 mV.
5. An anode as according to claim 4, wherein the electrochemical potential of the anode is in the range of -500 to -1100 mV.
6. An anode as according to any of the claims 2 to 5, wherein the capacity of the anode to protect the physical integrity of the cathode is in the range of 1000 to 2000 Ah/kg.
7. An alloy as according to claim 6, wherein the capacity of the anode to protect the physical integrity of the cathode is in the range of 1400 to 1700 Ah/kg.
9. An anode as according to any of the claims 2 to 7, for use in the galvanic protection of water vessels with non-metallic hulls.
9. An anode as according to claim 8, wherein the vessel is designed for use in seawater.
10. An anode as according to any of the claims 2 to 9, wherein the surface area ratio of the anode to the cathode in the electrochemical cell is in the range of 1:1 to 1:20.
11. An anode as according to claim 10, wherein the surface area ratio of the anode to the cathode is in the range of 1:2 to 1:20.
12. An anode as according to any of the claims 2 to 11, characterised in that an excess negative electrochemical potential is applied across the electrochemical cell.
CA002567681A 2006-11-03 2006-11-10 Alloy for use in galvanic protection Abandoned CA2567681A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU2006235903A AU2006235903B2 (en) 2006-11-03 2006-11-03 Alloy for use in galvanic protection
AU2006235903 2006-11-03

Publications (1)

Publication Number Publication Date
CA2567681A1 true CA2567681A1 (en) 2008-05-03

Family

ID=37890999

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002567681A Abandoned CA2567681A1 (en) 2006-11-03 2006-11-10 Alloy for use in galvanic protection

Country Status (7)

Country Link
US (1) US20080107560A1 (en)
EP (1) EP1918393B1 (en)
AT (1) ATE513933T1 (en)
AU (1) AU2006235903B2 (en)
CA (1) CA2567681A1 (en)
NO (1) NO20065162L (en)
NZ (1) NZ551262A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105256178A (en) * 2015-10-29 2016-01-20 无锡市嘉邦电力管道厂 Corrosion resisting aluminum alloy and preparing method thereof

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3368952A (en) * 1964-05-18 1968-02-13 Olin Mathieson Alloy for cathodic protection galvanic anode
US3496620A (en) * 1966-11-07 1970-02-24 Olin Mathieson Composite aluminum article
US6602363B2 (en) * 1999-12-23 2003-08-05 Alcoa Inc. Aluminum alloy with intergranular corrosion resistance and methods of making and use
JP4436553B2 (en) * 2000-09-25 2010-03-24 株式会社ナカボーテック Aluminum alloy for low temperature seawater environmental current anode
KR20050067605A (en) * 2003-12-29 2005-07-05 주식회사 삼공사 Aluminum alloy for galvanic anode

Also Published As

Publication number Publication date
NZ551262A (en) 2007-03-30
AU2006235903A1 (en) 2008-05-22
EP1918393A2 (en) 2008-05-07
EP1918393A3 (en) 2009-01-28
ATE513933T1 (en) 2011-07-15
EP1918393B1 (en) 2011-06-22
AU2006235903B2 (en) 2011-03-03
US20080107560A1 (en) 2008-05-08
NO20065162L (en) 2008-05-04

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Legal Events

Date Code Title Description
FZDE Discontinued

Effective date: 20121113