Editing Galvanization

{{Short description|Process of layering steel or iron with zinc to prevent rusting}}
{{Redirect2|Galvanize|Galvanized}}
{{Distinguish|Galvanism|Electrogalvanization}}

[[File:Feuerverzinktes Geländer.jpg|thumb|right|Galvanized surface with visible spangle]]
'''Galvanization''' ([[American and British English spelling differences|also spelled]] '''galvanisation''')<ref>{{cite web|title=Galvanize|work=[[Cambridge English Dictionary]]|url=https://dictionary.cambridge.org/dictionary/english/galvanize|access-date=10 November 2019}}</ref> is the process of applying a protective [[zinc]] coating to [[steel]] or [[iron]], to prevent [[rusting]]. The most common method is [[hot-dip galvanization|hot-dip galvanizing]], in which the parts are coated by submerging them in a bath of hot, molten zinc.<ref>{{Cite web |title=What is the HDG Process? |url=https://galvanizeit.org/hot-dip-galvanizing/hdg-process |access-date=2025-03-12 |website=American Galvanizers Association |language=en}}</ref>

==Protective action==
The zinc coating, when intact, prevents corrosive substances from reaching the underlying iron.<ref>{{cite web |title=How to Galvanize Metal to Protect Pipes |url=https://www.appmfg.com/blog/how-to-galvanize-metal-to-protect-pipes |website=www.appmfg.com |access-date=3 February 2022 |language=en}}</ref>  Additional [[electroplating]] such as a [[chromate conversion coating]] may be applied to provide further [[Passivation (chemistry)#Surface passivation|surface passivation]] to the substrate material.<ref>{{cite journal |last1=Magalhães |first1=A.A.O |last2=Margarit |first2=I.C.P |last3=Mattos |first3=O.R |title=Electrochemical characterization of chromate coatings on galvanized steel |journal=Electrochimica Acta |date=July 1999 |volume=44 |issue=24 |pages=4281–4287 |doi=10.1016/S0013-4686(99)00143-7 }}</ref>

==History and etymology==
[[File:NailsCloseup.jpg|thumb|Galvanized nails]]
The process is named after the Italian physician, physicist, biologist and philosopher  [[Luigi Galvani]] (9 September 1737 – 4 December 1798). The earliest known example of galvanized iron was discovered on 17th-century Indian armour in the [[Royal Armouries]] Museum collection in the United Kingdom.<ref>[https://web.archive.org/web/20150327062539/http://royalarmouries.org/what-we-do/research/analytical-projects/zinc-coatings-of-indian-plate-and-mail-armour ZINC COATINGS OF INDIAN PLATE AND MAIL ARMOUR]. Summary of XRF analysis conducted in September 1999 by the Royal Armouries Museum in Leeds and written up as part of a thesis by Helen Bowstead Stallybrass at the Department of Archaeological Sciences, [[Bradford University]].</ref>

The term "galvanized" can also be used metaphorically of any stimulus which results in activity by a person or group of people.<ref>{{cite book|title=The Oxford English Dictionary|edition=2|volume=VI|publisher=Oxford University Press|page=340|editor-last=Murray | editor-first = James A. H. |display-editors=etal|isbn=0 19 861218-4|url-access=registration|url=https://archive.org/details/oxfordenglishdic6simp/page/340|year=1989}}</ref> 
 
In modern usage, the term "galvanizing" has largely come to be associated with zinc coatings, to the exclusion of other metals. Galvanic paint, a precursor to [[hot-dip galvanizing]], was patented by [[Stanislas Sorel]], of [[Paris]], on June 10, 1837, as an adoption of a term from a highly fashionable field of contemporary science, despite having no evident relation to it.<ref>{{cite journal|url=https://books.google.com/books?id=W8oGAAAAYAAJ&dq=%22Specification+of+a+Patent+for+a+process+for+protecting+articles+made+of+Iron+or+Steel+from+oxidation.%22&pg=PA52 |title= Specification of a Patent for a process for protecting articles made of Iron or Steel from oxidation|author= Sorel, M. |journal= Journal of the Franklin Institute (Philadelphia, Pa.)|publisher= Pergamon Press|date= 1838}}</ref>

==Methods==
[[Hot-dip galvanizing]] deposits a thick, robust layer of zinc iron alloys on the surface of a steel item. In the case of [[automobile]] bodies, where additional decorative coatings of paint will be applied, a thinner form of galvanizing is applied by [[electrogalvanization|electrogalvanizing]]. The hot-dip process generally does not reduce strength to a measurable degree, with the exception of high-strength steels where [[hydrogen embrittlement]] can become a problem.<ref>{{cite web |url=http://www.galvanizeit.org/designing-fabricating/design-considerations/steel-selection/ |publisher=American Galvanizers Association |title=Steel Selection |access-date=3 April 2015 |archive-date=21 August 2013 |archive-url=https://web.archive.org/web/20130821041723/http://www.galvanizeit.org/designing-fabricating/design-considerations/steel-selection |url-status=dead }}</ref>

Thermal diffusion galvanizing, or [[Sherardizing]], provides a zinc diffusion coating on iron- or copper-based materials.<ref name="Zinchand">{{cite book |last=Porter |first=Frank C. |date=1991 |title=Zinc Handbook |publisher=CRC Press |isbn=978-0-8247-8340-2 |url=https://books.google.com/books?id=laACw9i0D_wC&q=sherardizing}}</ref><ref name="MittemeijerSomers2014">{{cite book |last1=Natrup |first1=F. |last2=Graf |first2=W. |editor1-last=Mittemeijer |editor1-first=Eric J. |editor2-last=Somers |editor2-first=Marcel A. J. |date=21 November 2014 |title=Thermochemical Surface Engineering of Steels: Improving Materials Performance |chapter=20 – Sherardizing: corrosion protection of steels by zinc diffusion coatings |publisher=Elsevier Science |isbn=978-0-85709-652-4 |chapter-url=https://books.google.com/books?id=8I-uAwAAQBAJ&pg=737 |page=737}}</ref>

==Eventual corrosion==
[[File:Rust 1.jpeg|thumb|right|Rusted corrugated steel roof]]
Galvanized steel can last for many decades if other supplementary measures are maintained, such as [[paint]] coatings and additional [[sacrificial anode]]s. Corrosion in non-salty environments is caused mainly by levels of [[sulfur dioxide]] in the air.<ref>{{cite web|url=http://www.galvanizing.org.uk/about_galvanizing/corrosion_performance/atmospheric_resistance |title=Atmospheric Resistance |publisher=Galvanising Association (UK) |url-status=dead |archive-url=https://web.archive.org/web/20140222165139/http://www.galvanizing.org.uk/about_galvanizing/corrosion_performance/atmospheric_resistance |archive-date=2014-02-22 }}</ref>

==Galvanized construction steel==
This is the most common use for galvanized metal; hundreds of thousands of tons of steel products are galvanized annually worldwide. In developed countries, most larger cities have several galvanizing factories, and many items of steel manufacture are galvanized for protection. Typically these include street furniture, building frameworks, balconies, verandahs, staircases, ladders, walkways, and more. Hot dip galvanized steel is also used for making steel frames as a basic construction material for steel frame buildings.<ref>{{Cite web|last=marshall|date=2019-10-11|title=Galvanized Steel: Types, Uses, Benefits|url=https://punjabpipestore.com/gi-pipes/|access-date=2021-02-06|website=National Material Company – Steel Processing Facilities|language=en-US}}</ref>

==Galvanized piping==
{{See also|Galvanic corrosion|Pipe (fluid conveyance)|Piping}} 
In the early 20th century, galvanized piping swiftly took the place of previously used [[Cast iron pipe|cast iron]] and [[Pipe (fluid conveyance)#Materials|lead]] in [[Tap water|cold-water]] [[plumbing]]. Galvanized piping rusts from the inside out, building up layers of plaque on the inside of the piping, causing both water pressure problems and eventual pipe failure. These plaques can flake off, leading to visible impurities in water and a slight metallic taste. The life expectancy of galvanized piping is about 40–50 years,<ref>{{Cite web|last=Biard & Crockett|date=2016-05-16|title=How Long Will My Galvanized Pipes Last?|url=https://www.bcpsi.com/galvanized-pipes/|access-date=2021-02-06|website=Biard & Crockett}}</ref> but it may vary on how well the pipes were built and installed. Pipe longevity also depends on the thickness of zinc in the original galvanizing, which ranges on a scale from G01 to G360.<ref>{{Cite web|last=American Galvanizers Association|date=|title=Zinc Coatings|url=http://courtgalvanizinginc.com/wp-content/uploads/2012/04/Zinc_Coatings.pdf|archive-url=|archive-date=|access-date=|website=courtgalvanizinginc.com}}</ref>

== See also ==
{{div col|colwidth=30em}}
* [[Electroplating]]
* [[Aluminized steel]]
* [[Cathodic protection]]
* [[Corrugated galvanized iron]]
* [[Galvanic corrosion]]
* [[Galvannealed]] – galvanization and annealing
* [[Prepainted metal]]
* [[Rust]]
* [[Rustproofing]]
* [[Sendzimir process]]
* [[Sherardizing]]
* [[Corrosion]]
* [[Sacrificial metal]]
* [[Corrosion engineering]]
{{div col end}}

==References==
{{Reflist|30em}}

==External links==
* {{cite journal |last1=Pchelintseva |first1=Irina Yu. |last2=Pchelintsev |first2=Alexander N. |last3=Litovka |first3=Yuriy V. |title=Modeling of metal distribution when coating flat metal plates in electroplating baths |journal=International Journal of Numerical Modelling: Electronic Networks, Devices and Fields |date=March 2021 |volume=34 |issue=2 |doi=10.1002/jnm.2830 }}
{{Wiktionary|galvanize}}
{{Commons category|Galvanization}}

{{Authority control}}

[[Category:Chemical processes]]
[[Category:Corrosion prevention]]
[[Category:Metal plating]]
[[Category:Zinc]]
[[Category:Bimetal]]