oxygen on corrosion

You should start by searching online for the definition of corrosion. Once you have satisfied yourself that you know what it is, you can ask more specific questions. We'll still be here.

Mike

All you had to do was explain, you remind me of this tutor at my school that nobody likes, when asked to show how a problem is done...he says figure it out, he doesn't understand that if a person is unfamiliar with something...it's hard to comprehend it at first, especially when a teacher that cannot teach explains it.

Corrosion is the chemical process of "oxidation" where oxigen combines with the material.

Rust is "Iron Oxide"

The white powder on aluminum is "aluminum Oxide"

This is not enough to pass your homework. Better to read your books

Funny how the homework questions have not changed in 30 years!

Oxigen?! or Oxygen?

Typos happen. Get over it. Or be an English teacher (if you aren't already).

"...Oxigen?! or Oxygen?..."

Is this the issue?

Thanks Techno for keeping it simple, unlike "Dum Dum Head", who said look it up.

There's no excuse for laziness

your question is short and sweet but needs a lot understanding.

To get some idea on corrosion aspects, The International Nickel Co. (Mond) Ltd. of UK. had made a film on the subject matter, titled "Corrosion in Action". This highlights all types of corrosion that one comes across, including the one you are asking about.

Hope, you can trace the Film or the Notes on the film to get full understanding of subject. The notes in question are shown with slide pictures and corresponding details on same.

The International Nickel Co. (Mond) Ltd.

Thames House, Millbank, London SW1. UK.

Thanks chitterlings!

Just kidding, I couldn't resist that one. Thanks chittaranjan. I think I spelled your name right.

Oxygen is only one part of the corrosion cycle. It generally requires an aqueous medium where cations and anions migrate to form the new compounds which are oxides, hydroxides and more complex molecules of the two. Confusingly, oxidation is the term applied for many of the corrosion types even when it is not an oxide that is produced (e.g. silver sulphide is the black substance on the face of silverware).

Unfortunately, it will require a substantial amount of reading to get close to answering your question. This is because there are so many factors that influence the rate of corrosion and the type of corrosion that asking how oxygen influences corrosion is like asking how the surface of the road influences how a car performs: too many things unsaid.

A couple of pointers: iron castings form oxides on their surface which are characterised by a reddish powder which is the more common of the two iron oxides, iron beams (and other rolled products) will form rust in their laminations which are a combination of iron oxide and hyroxides, aluminium naturally forms a layer of aluminium hyroxide which is inert and so remains a thin dusty unsightly layer, aluminium is treated in the factory to form a very thin aluminium oxide layer which is also relatively inert, titanium is relatively inert due to the thin oxide layer.

Cutting any metal gives a shiny appearance, the more reactive the metal the quicker it will dull due to oxidation with the air.

Hopefully this is the beginning of your knowledge on oxidation etc. But you must read alot more about it if you are to answer your own question.

until a rating system for posts installed

Corrosion....yikes....

consider corrosion as a battery

you need three things

electrical potential - always present in metal because it is not at "rest" or in a natural state as found in nature

metals contain various elements all having different electrical potential creating a natural cathode and anode point to exchange electrons

Electrolyte - this is likely to be water carrying elements allowing the transfer of a charge (known as a brine solution) - like you would find in a battery

Oxygen - required for the oxidation process - free oxygen will attach readily to iron to form iron oxide to bring it to a natural state

this is why we paint - form an osmotic barrier and to keep it dry underneath to eliminate the potential for an electrolyte to form

no oxygen, no electrolyte = no electron exchange = no corrosion

simple physics, simple answer, common sense

We all need some more of this stuff. Cheers, guest. Sign in or register, and be blessed.

Corrosion = oxidation. Nough said?

I'll try to keep it simple.

Oxygen has a role in corrosion process 'cause it's usually the cathodic part of the corrosion.

In order to have corrosion you need an anodic reaction, dissolution of iron for example wich consume electrons, and a cathodic reaction that gives the electron necessary to the anodic reaction.

So for example if you have iron in water and you can keep all the oxygen out of the water, or at least under a value of we can say 8 ppb, and there are no other oxydant in the water, there will be no corrosion because there will be no reaction that can provide electrons.

So the corrosion of iron in air, is due to the oxygen in the atmosphere.

Hope this help

Vict

This is the best way relation between oxygen and corrosion is explained and you should have this base to go deeper through authenic books, if further interested.

I've made a mistake in my reply.

Is the anodic reaction that produce electrons, for example: Fe --- Fe 2+ + 2 e-

and the cathodic consume the electrons, for example: O2 + 4e- + H2O ----- 4 OH-

sorry.

Vict