EP3835441A1 - Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle - Google Patents

Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle Download PDF

Info

Publication number
EP3835441A1
EP3835441A1 EP19215052.2A EP19215052A EP3835441A1 EP 3835441 A1 EP3835441 A1 EP 3835441A1 EP 19215052 A EP19215052 A EP 19215052A EP 3835441 A1 EP3835441 A1 EP 3835441A1
Authority
EP
European Patent Office
Prior art keywords
weight
aluminium
maximum
based alloy
sacrificial anode
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.)
Withdrawn
Application number
EP19215052.2A
Other languages
German (de)
English (en)
Inventor
Christian Thomsen
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.)
BAC CORROSION CONTROL AS
Original Assignee
BAC CORROSION CONTROL AS
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 BAC CORROSION CONTROL AS filed Critical BAC CORROSION CONTROL AS
Priority to EP19215052.2A priority Critical patent/EP3835441A1/fr
Priority to EP20204306.3A priority patent/EP3835442A1/fr
Publication of EP3835441A1 publication Critical patent/EP3835441A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/10—Alloys based on aluminium with zinc as the next major constituent
    • 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
    • C23F13/12—Electrodes characterised by the material
    • C23F13/14—Material for sacrificial anodes
    • 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

Definitions

  • the present invention relates to an aluminium-based alloy for use in a sacrificial anode and a sacrificial anode produced from the aluminium-based alloy.
  • Cathodic protection using sacrificial anodes is a well-known technique within a number of areas including ships, vessels and offshore constructions, e.g. oil exploitation rigs.
  • the electrochemical process taking place is generally along the following scheme for a ferrous material: Fe ⁇ Fe 2+ + 2e - O 2 + 2H 2 O + 4e - ⁇ 4OH - 2H 2 O + 2e - ⁇ H 2 + 2OH -
  • ferrous hydroxide also known as rust: F e 2+ + 2OH - ⁇ Fe(OH) 2
  • anode materials are aluminium or zinc or alloys comprising aluminium or zinc as the main component, but other materials may be used as alternatives to zinc and aluminium, such as magnesium as well as alloys containing magnesium.
  • the sacrificial anodes should be of a type suitable to the environment of operation, i.e. taking into consideration the chemical composition of the environment and also the temperature. Furthermore, the size of the anode(s) as well as their mutual positioning are relevant to consider in order to provide a satisfactory protection.
  • anode construction for the purpose of arranging anodes to an offshore construction, pipelines or other equipment
  • the previously known construction comprises a framework with the anodes placed in mutually distanced positions to ensure the proper functioning of the cathodic protection.
  • the anodes are connected to suitable connection points of the construction to be protected by means of suitable wiring.
  • Such previously known anode construction is relatively bulky and therefore difficult to transport from the production site to the actual operational site.
  • the alloy compositions described herein are designed to have high operating efficiencies to make the alloy as cost-effective as possible, high current output to enable high and long-lasting performance for a given weight of anode (energy density), and optimized operating potential, which will vary depending on the application.
  • An important added benefit is that in the alloys of this invention the content of zinc is very low.
  • the most used commercial aluminium anode alloy is aluminium-5% zinc-0.02% indium.
  • This alloy is specified in MIL-DTL-24779 and has proven to be very effective in worldwide climates to protect a variety of materials including iron, steel, and aluminium piers, ships, off-shore rigs, and bridges among other applications. It is approximately 90% efficient, which is lower than pure zinc, which is about 98% efficient, but much higher than magnesium, which is about 60% efficient.
  • Zinc is an aquatic toxin and contains residual cadmium from the mining process. Zinc is known to be toxic for marine plants and animals. Consequently, there is a raising demand for alloys in which the content of zinc is very low, but which still provide the same outstanding efficiency, current output and energy density.
  • the alloy of this invention has the potential to replace the aluminium-zinc-indium alloy for use as described above. Moreover, zinc is also more expensive than aluminium. Thus, replacing the amount of zinc in an alloy with aluminium, reduces the cost of producing the alloy.
  • An object of the present invention is to provide an alloy for sacrificial anodes which is environmental friendly and can be produced in a cost-effective manner.
  • a further object is to provide a sacrificial anode based on aluminium and with a very low amount of zinc, which provides good properties in respect of cathodic protection of more noble metals.
  • the present invention relates to an aluminium-based alloy for use in a sacrificial anode, which alloy comprises:
  • balance indicates that aluminium constitutes the amount of the alloy which is required to reach 100% by weight, e.g. if the combined amount of zinc, indium, gallium, iron, copper, and optional impurities constitutes 0.5% byweight, the amount of aluminium constitutes 99.5% by weight.
  • maximum indicates that the specified percentage is the maximum content of the metal in the alloy.
  • the alloy may also comprise elements in form of impurities in an amount of maximum 0.02% by weight of each element.
  • the impurities may e.g. be constituted by magnesium, mangan, silicium, chrome, cadmium, tin, boron and other elements.
  • the impurities may originate from the aluminium grade used.
  • the high amount of aluminium combined with low amounts of zinc, indium, gallium, iron, and copper provides an alloy for a sacrificial anode with good properties and which is significantly lesser harmful to the environment that sacrificial anodes comprising high amounts of zinc.
  • the aluminium-based alloy comprises:
  • the amount of impurities present in the alloy may be larger than the amount of some of the individual elements: zinc, indium, gallium, iron, and copper, the lower presence of these metals, however, appears to improve the electrochemical properties of the alloy.
  • the aluminium in the aluminium-based alloy generally has a high purity, and in an embodiment the aluminium has a purity of at least 99,0% by weight.
  • the aluminium has a purity of at least 99,5% by weight.
  • the aluminium may have purities in the ranges 99.00 to 99.99% byweight, preferably in the ranges 99.50 to 99.99% by weight, such as purities in the ranges 99.90 to 99.99 % by weight.
  • the aluminium-based alloy according to the invention has an excellent electrochemical efficiency, and in an embodiment the aluminium-based alloy has an electrochemical efficiency above 1500 Ah/kg, preferably above 2000 Ah/kg, such as above 2500 Ah/kg, when tested according to the DNV GL standards, such as DNV RP B401.
  • the aluminium-based alloy according to the invention has low potential (potential vs. Ag/AgCI), and in an embodiment the potential is even lower than -800mV, such as lower than -1000mV.
  • the aluminium-based alloy according to the invention is able to provide a very good cathodic protection to more noble metals, e.g. steel.
  • the invention also relates to the use of an aluminium-based alloy in a sacrificial anode for protecting metallic constructions in a humid and marine environment, said aluminium-based alloy comprising:
  • the aluminium may have purities in the ranges 99.00 to 99.99% by weight, preferably purities in the ranges 99.50 to 99.99% byweight, such as a purity in the ranges 99.90 to 99.99% by weight.
  • the use according to the invention provides sacrificial anodes with an excellent electrochemical efficiency, and in an embodiment the anodes with the aluminium- based alloy has an electrochemical efficiency above 1500 Ah/kg, preferably above 2000 Ah/kg, such as above 2500 Ah/kg, when tested according to the DNV GL standards such as DNV RP B401.
  • the use according to the invention also provides sacrificial anodes with low potential (potential vs. Ag/AgCI), and in an embodiment the potential is even lower than -800mV, such as lower than -1000mV.
  • sacrificial anodes with very good cathodic protection to more noble metals, e.g. steel.
  • the invention further relates to a sacrificial anode for protecting metallic constructions in a humid and marine environment, said sacrificial anode comprising an aluminium-based alloy comprising:
  • the aluminium in the aluminium-based alloy may have purities in the ranges 99.00 to 99.99% byweight, preferably purities in the ranges 99.50 to 99.99% byweight, such as a purity in the ranges 99.90 to 99.99% by weight.
  • the sacrificial anode according to the invention has an excellent electrochemical efficiency, and in an embodiment the sacrificial anode with the aluminium-based alloy has an electrochemical efficiency above 1500 Ah/kg, preferably above 2000 Ah/kg, such as above 2500 Ah/kg, when tested according to the DNV GL standards, such as DNV RP B401.
  • the sacrificial anode has a low potential (potential vs. Ag/AgCI), and in an embodiment the potential is lower than -800mV, such as lower than -1000mV.
  • potential vs. Ag/AgCI potential vs. Ag/AgCI
  • use of the aluminium-based alloy provides sacrificial anodes with very good cathodic protection to more noble metals.
  • Figure 1A shows an embodiment of a sacrificial anode 10.
  • the sacrificial anode comprises the aluminium alloy 12 shaped as a bar and with connection pieces 14 at each end.
  • the connection pieces 14 comprise holes by which the sacrificial anode 10 can be connected to the item which requires cathodic protection by means of bolts or screws.
  • Figure 1B shows another embodiment of a sacrificial anode 10 with sacrificial alloy 12 and connectors 14.
  • the connectors 14 can be welded to the item that requires cathodic protection.
  • Figure 1C shows yet an embodiment of a sacrificial anode 10 with sacrificial alloy 12 and connectors 14.
  • the connecters 14 are "S"-shaped and can be attached by welding to the structure which requires cathodic protection.
  • the amount of the sacrificial alloy 12 shaped as a bar may be 100 kg or more.
  • a sacrificial anode according to the invention was produced using the aluminium-based alloy with the approximate composition: Zinc: 0.5% by weight Indium: 0.02% by weight Gallium: 0.05% byweight Iron: 0.06% byweight Copper: 0.002% byweight Impurities: 0.03% by weight in total Aluminium: balance
  • the aluminium-based alloy was shaped into a cylindrical rod constituting a sacrificial anode, and the electrochemical efficiency and the potential were determined.
  • the sacrificial anode had an electrochemical efficiency above 2500 Ah/kg when tested according to the DNV GL standards, such as DNV RP B401.
  • the sacrificial anode had a potential (potential vs. Ag/AgCI) lower than -1050mV.
  • the sacrificial anode provided very good properties in respect of cathodic protection for metallic 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)
EP19215052.2A 2019-12-10 2019-12-10 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle Withdrawn EP3835441A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP19215052.2A EP3835441A1 (fr) 2019-12-10 2019-12-10 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle
EP20204306.3A EP3835442A1 (fr) 2019-12-10 2020-10-28 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19215052.2A EP3835441A1 (fr) 2019-12-10 2019-12-10 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle

Publications (1)

Publication Number Publication Date
EP3835441A1 true EP3835441A1 (fr) 2021-06-16

Family

ID=68848178

Family Applications (2)

Application Number Title Priority Date Filing Date
EP19215052.2A Withdrawn EP3835441A1 (fr) 2019-12-10 2019-12-10 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle
EP20204306.3A Pending EP3835442A1 (fr) 2019-12-10 2020-10-28 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP20204306.3A Pending EP3835442A1 (fr) 2019-12-10 2020-10-28 Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle

Country Status (1)

Country Link
EP (2) EP3835441A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4885045A (en) * 1987-06-16 1989-12-05 Comalco Aluminum Limited Aluminium alloys suitable for sacrificial anodes
US20130084208A1 (en) * 2011-09-30 2013-04-04 Questek Innovations Llc Aluminum-based alloys

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7958052B2 (en) 2007-12-31 2011-06-07 Mastercard International Incorporated Methods and systems for cardholder initiated transactions
US20190078179A1 (en) 2017-09-14 2019-03-14 United States Of America As Represented By The Secretary Of The Navy Aluminum Anode Alloy

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4885045A (en) * 1987-06-16 1989-12-05 Comalco Aluminum Limited Aluminium alloys suitable for sacrificial anodes
US20130084208A1 (en) * 2011-09-30 2013-04-04 Questek Innovations Llc Aluminum-based alloys

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ANSHUMAN SHARMA ET AL: "and thermodynamic modelling of alloying effects on activity of sacrificial aluminium anodes", CORROSION SCIENCE, OXFORD, GB, vol. 53, no. 5, 20 January 2011 (2011-01-20), pages 1724 - 1731, XP028156793, ISSN: 0010-938X, [retrieved on 20110128], DOI: 10.1016/J.CORSCI.2011.01.046 *

Also Published As

Publication number Publication date
EP3835442A1 (fr) 2021-06-16

Similar Documents

Publication Publication Date Title
CN101288924B (zh) 一种耐海水腐蚀埋弧焊丝盘条、焊丝及其应用
JP5807669B2 (ja) 耐海水腐食性に優れたステンレスクラッド鋼板
KR20160075746A (ko) 해양응용을 위한 내식스틸
US20110300395A1 (en) Corrosion Protection System for Offshore Steel Structures and a Method for its Application
CN102605295B (zh) 一种耐酸性土壤腐蚀的接地网耐蚀合金材料
EP3835442A1 (fr) Alliage destiné à être utilisé dans une anode sacrificielle et anode sacrificielle
CN103781930A (zh) 生态弹药
CA3075878C (fr) Alliage d'aluminium anodique
US6251240B1 (en) Mg-Ca sacrificial anode
Mobin et al. Corrosion control by cathodic protection
JP4241552B2 (ja) 水素侵入抑制効果を有する高強度低合金鋼
US2541062A (en) Utilization of aluminous metal electrodes in cathodic protection installations
US2805198A (en) Cathodic protection system and anode therefor
JPH07118784A (ja) 鋼構造物防食用アルミニウム合金
WO2000026426A1 (fr) Alliage a base de zinc, son utilisation comme anode soluble, anode soluble et procede de protection cathodique de constructions menacees par la corrosion dans un environnement agressif
CN110814577A (zh) 适用于干湿交替环境下的铜包钢接地网放热熔钎焊焊粉
EP3647465A1 (fr) Alliage d'anode sacrificielle à base de zinc, utilisation d'un alliage à base de zinc et anode sacrificielle
US5547560A (en) Consumable anode for cathodic protection, made of aluminum-based alloy
DE19702953C2 (de) Magnesiumwerkstoff mit einer Korrosionsschutzschicht
WO2017034486A1 (fr) Alliage d'aluminium pour anode sacrifiée
US3582319A (en) A1 alloy useful as anode and method of making same
JP5167863B2 (ja) 鋼構造物防食電着被膜形成用陽極
Leheta et al. Cathodic Protection design procedure for steel offshore structures
Ekhasomhi et al. Design of a cathodic protection system for 2,000 barrels crude oil surge tank using zinc anode
Efendi et al. ZINC ANODE ANALYSIS USED KRI WITH COMPOSITION AND POTENTIAL CORROSION PARAMETERS TEST

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20211217