Previous in Forum: Which MCU Processor Is Used On CFM56-5B Engine's ECU?   Next in Forum: HVAC cooling tip & Question
Close
Close
Close
34 comments
Participant

Join Date: Aug 2007
Posts: 3

Reverse process of a Corrosion

08/10/2007 7:44 AM

Hi All,

What is the reverse process of a Corrosion?

Thanks,

Mani.

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Engineering Fields - Manufacturing Engineering - New Member Hobbies - Target Shooting - New Member United States - Member - New Member Hobbies - Hunting - New Member

Join Date: Dec 2006
Location: Charlotte, NC USA
Posts: 782
Good Answers: 17
#1

Re: Reverse process of a Corrosion

08/10/2007 7:51 AM

What is the reverse process of growing old?

__________________
Be careful of what you wish for .....
Register to Reply
2
Guru

Join Date: Jul 2007
Location: UK, Midlands
Posts: 515
Good Answers: 2
#2

Re: Reverse process of a Corrosion

08/10/2007 7:51 AM

"Reduction"

__________________
Wish I was here more often.
Register to Reply Good Answer (Score 2)
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16499
Good Answers: 662
#3

Re: Reverse process of a Corrosion

08/10/2007 7:52 AM

Deposition? Plating? Welding?

I dunno, I give up ...What is the reverse process of corrosion?

__________________
health warning: These posts may contain traces of nut.
Register to Reply
Anonymous Poster
#4

Re: Reverse process of a Corrosion

08/10/2007 9:59 AM

I had a corrosion once... a couple shots from the Doc and I was as good as new!!

Register to Reply
Guru

Join Date: Jul 2007
Location: 30°30'N, 97°45'W, Elv: 597 ft.
Posts: 2411
Good Answers: 10
#5

Re: Reverse process of a Corrosion

08/10/2007 12:32 PM

as I understand corrosion. it is either the deterioration of metal OR the deposition of impurities, OR both. A plugged drain can result from corrosion, deposition. A hole can be generated as a result of corrosion, deterioration.

So the opposite of corrosion - cleaning!

CR3

__________________
I never apologize. I'm sorry that's just the way I am.
Register to Reply
Guru
United Kingdom - Member - Olde Member!! Engineering Fields - Instrumentation Engineering - New Member

Join Date: Jul 2006
Location: Dunstable, England
Posts: 2821
Good Answers: 45
#6

Re: Reverse process of a Corrosion

08/10/2007 12:39 PM

What's the reverse of entropy?

__________________
A little knowledge is a dangerous thing - Googling is far worse!
Register to Reply
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16499
Good Answers: 662
#7

Re: Reverse process of a Corrosion

08/10/2007 12:46 PM

! emit ni kcab og ot si yaw ylno ehT .

leD

__________________
health warning: These posts may contain traces of nut.
Register to Reply Off Topic (Score 4)
Power-User

Join Date: Jul 2006
Posts: 295
Good Answers: 4
#8

Re: Reverse process of a Corrosion

08/11/2007 1:18 AM

Corrosion is generally speaking, that is not specifically, oxidation. The reverse process would be deoxidizing.

Ha!...the reverse process of corrosion is decorrosion.

Register to Reply
Guru
United States - Member - New Member Technical Fields - Education - New Member Popular Science - Cosmology - New Member

Join Date: Dec 2006
Location: Boca Raton, Florida
Posts: 576
Good Answers: 13
#11
In reply to #8

Re: Reverse process of a Corrosion

08/11/2007 12:08 PM

Ha!...the reverse process of corrosion is decorrosion.

Or uncorrosion? Seriously though, some of the other replies already got it -- corrosion mainly results from oxidation of a metal to metal oxide, so the opposite process would be *reduction* (or "plating") of a metal oxide back to metal.

__________________
Problems worthy of attack prove their worth by hitting back. -- Piet Hein
Register to Reply
Guru
Engineering Fields - Retired Engineers / Mentors - New Member

Join Date: Dec 2006
Location: Brecksville, OH
Posts: 1607
Good Answers: 18
#14
In reply to #11

Re: Reverse process of a Corrosion

08/11/2007 10:09 PM

The problem with corrosion is that one is generally concerned about corrosion (oxidation) in a specific uncontrolled area. While there are means to eliminate or reverse corrosion, there is (as far as I know) no means to eliminate or reverse corrosion in specific targeted areas. Except perhaps by sacrificial oxidation of the surfaces.

__________________
"Consensus Science got us into this mess, then why can't it get us out?" : Rephrase of Will Rogers Comment
Register to Reply
Guru
United States - Member - New Member Technical Fields - Education - New Member Popular Science - Cosmology - New Member

Join Date: Dec 2006
Location: Boca Raton, Florida
Posts: 576
Good Answers: 13
#16
In reply to #14

Re: Reverse process of a Corrosion

08/12/2007 9:21 AM

there is (as far as I know) no means to eliminate or reverse corrosion in specific targeted areas.

Good point. And even if we can reverse metal corrosion in targeted areas, the final metal surface would be rough and the regenerated metal only loosely held. The metal oxide formed during the original corrosion process tends to be porous and raised off of the metal surface. As pointed out by several members, that oxide can be converted back to metal (i.e., by electric current or by "electroless" chemical reduction), but the regenerated metal retains the shape of the porous oxide. Not a very satisfactory result.

__________________
Problems worthy of attack prove their worth by hitting back. -- Piet Hein
Register to Reply
Power-User

Join Date: Apr 2007
Posts: 270
Good Answers: 18
#9

Re: Reverse process of a Corrosion

08/11/2007 5:20 AM

Inverse corrosion for:

Metals - Electroplating, galvanising, sacrificial anodes combined with a wet layer of the required cathodic deposition material.

Plastics - Spraying on of coatings, dipping

Wood - (tricky one this) mainly consists of repairs

Concrete - Spraycrete, sacrificial anodes for the reinforcement

Fabric - Cooperative silk worms

Glass - Projected coatings (generally sputtered on), self-cleaning coatings

__________________
omw7
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#10

Re: Reverse process of a Corrosion

08/11/2007 7:34 AM

You have had the funny (some were really great!) answers, maybe you should tell us why you want to know.....it might change the tone of the answers for you.

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Power-User

Join Date: Jun 2007
Location: Gulf Coast
Posts: 209
Good Answers: 7
#12

Re: Reverse process of a Corrosion

08/11/2007 2:53 PM

The only way I can think of is electro plating, as Del was first to note, but that's not a reversal; its a adding upon what may have already electrolytically decayed.

One preventative that comes close is cathodic protection with sacrificial anodes like zinc or active anodes. Some ships are equipped with an active cathodic protection system. This (very basically) consists of emitters (active anodes) that emit current to the designed surrounding metal creating an electrical potential whereby the parent metal will retain its electrons that would normally be attracted away (thus corroding) by an undesired electrolytic action. These systems can work quite well as long as the monitoring probe is functioning properly, but can have a very averse effect in the wrong environments and with the wrong parent metals. I heard of some aluminum hulls getting 'eaten up'.

__________________
In my many years I have come to a conclusion that one useless man is a shame, two is a law firm, and three or more is a congress. - John Adams
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#15
In reply to #12

Re: Reverse process of a Corrosion

08/12/2007 3:11 AM

You mentioned, quite correctly "Some ships are equipped with an active cathodic protection system."

Such systems, not only have sacrificial anodes of some base metal, but they also monitor the currents obtained between hull and anode and apply a reverse current to nullify the corrosion current, that will flow between dissimilar metals when immersed in sea water. Its like a simple battery. It has to be set up on a regular basis to just nullify and not add to any corrosion. This is needed due to changes in the ships position, water salinity etc etc...

Maybe it sets itself up automatically today and in this case it did not do a good job, just guessing though!!

If aluminium hulls are being "eaten" away, then the system was incorrectly set up (or installed) in the first place....

Depending upon the Hull metal, sacrificial anodes must be made of a "less noble" metal, (taken from the periodic table of metals)....in my limited experience Zinc or similar, but maybe aluminum needs something else to fully prevent corrosion. I only worked with steel, wood and fiberglass hulls.....aluminium was only used to build the upper works of certain 60s style warships.....it has proved to be a problem there for other reasons, not corrosion....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Power-User

Join Date: Jun 2007
Location: Gulf Coast
Posts: 209
Good Answers: 7
#17
In reply to #15

Re: Reverse process of a Corrosion

08/12/2007 1:14 PM

Hi Andy,

What you are referring to is the galvanic series chart that illustrates the nobility of one metal in comparison to others.

The systems that I was familiar with some years ago were manually monitored and adjusted. I imagine that the new ones are much more sophisticated.

Zinc is still the most favored sacrificial anode used on both steel and aluminum vessels today.

__________________
In my many years I have come to a conclusion that one useless man is a shame, two is a law firm, and three or more is a congress. - John Adams
Register to Reply
Power-User
Engineering Fields - Piping Design Engineering - Environmental Contractor United States - Member - Born, raised and proud to be Texan Safety - Hazmat - New Member

Join Date: Nov 2006
Location: South of Alabama
Posts: 196
#13

Re: Reverse process of a Corrosion

08/11/2007 2:57 PM

Wrenched had it in post 2. Where are all our chemists?

__________________
Believe none of what you hear......and only half of what you see.
Register to Reply
4
Guru

Join Date: Jun 2007
Posts: 1035
Good Answers: 40
#18
In reply to #13

Re: Reverse process of a Corrosion

08/12/2007 1:33 PM

I find myself biting-my-lip occasionally, debating whether to add fuel to the raging inferno, or throw water on it. Herewith, a splash of H2O.

According to NACE (National Association of Corrosion Engineers International), virtually everything is subject to corrosion, with corrosion defined as "the deterioration of a material due to interaction with its environment." Plastics, concrete, even glass can and do corrode given the right (or wrong) environment.

When speaking of corrosion of metals, corrosion involves REDOX reactions ... both Reduction AND Oxidation must occur simultaneously, or there is no corrosion. Oxidation is the losing or giving-up of an electron (in no way is oxygen *Required* for oxidation to occur, period). Reduction is the gaining or picking-up of an electron. Oxidation occurs at the anodic site of a corrosion cell; reduction occurs at the cathode of a corrosion cell. Since the reduction of oxygen (at the cathode, mind you!) is one of the most common cathodic reactions encountered, the vast majority of people get mislead in their comprehension of the process.

The post that mentioned a battery stopped a wee bit short.

A typical (carbon-zinc, alkaline, or even lead-acid) battery is a perfect example of a corrosion cell. [The 4 mandates for a metallic corrosion cell are: Anode - Cathode -Metallic Path - Electrolyte] The lead-acid battery is "rechargeable" because it employs material which, in the electrolyte provided, can corrode unleashing tremendous volumes of electrons... then, by use of a generator (or rectified alternator) can "push" electrons back into the fancy alloy... to a pretty fair degree "uncorroding" it, or reversing the corrosion reaction that took place during discharge.

For every different metallic corrosion in every different environment* (*electrolyte presence ~ for without the electrolyte, no corrosion) there is a different set of anodic & cathodic reactions that takes place. Thus, there would be an equal number of equivalent "reverse" reactions to distinguish the variations of "reverse corrosion".

Hope this clarified some of the mud ~

Register to Reply Good Answer (Score 4)
Power-User
Engineering Fields - Piping Design Engineering - Environmental Contractor United States - Member - Born, raised and proud to be Texan Safety - Hazmat - New Member

Join Date: Nov 2006
Location: South of Alabama
Posts: 196
#22
In reply to #18

Re: Reverse process of a Corrosion

08/12/2007 5:17 PM

Excellent.......and thanks.

__________________
Believe none of what you hear......and only half of what you see.
Register to Reply
Guru

Join Date: Jul 2007
Posts: 4448
Good Answers: 143
#19

Re: Reverse process of a Corrosion

08/12/2007 1:52 PM

Refining. Iron oxide + blacksmith = iron. OK, a little more effort than that, but millenia old.

__________________
"Well, I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it." Elwood P. Dowd
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#20
In reply to #19

Re: Reverse process of a Corrosion

08/12/2007 1:59 PM

Simple and to the point!!

Doesn't steel mainly come from Pittsburg, USA, or have I mixed up my towns!! (School is a LONG way behind me, sorry!!)

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Power-User
Engineering Fields - Piping Design Engineering - Environmental Contractor United States - Member - Born, raised and proud to be Texan Safety - Hazmat - New Member

Join Date: Nov 2006
Location: South of Alabama
Posts: 196
#21
In reply to #20

Re: Reverse process of a Corrosion

08/12/2007 5:12 PM

Mine unfortunately seems to come from overseas in the form of carbon steel pipe. I think it started as scrap from the US.

__________________
Believe none of what you hear......and only half of what you see.
Register to Reply Off Topic (Score 5)
Guru

Join Date: Jul 2007
Posts: 4448
Good Answers: 143
#24
In reply to #20

Re: Reverse process of a Corrosion

08/12/2007 7:00 PM

Not so much anymore. It's pretty much all gone to overseas producers. Anyway, it's a lot easier to breathe now.

__________________
"Well, I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it." Elwood P. Dowd
Register to Reply Off Topic (Score 5)
Guru

Join Date: Jun 2007
Posts: 1035
Good Answers: 40
#23
In reply to #19

Re: Reverse process of a Corrosion

08/12/2007 5:48 PM

Another well-stated & appropriate point... along the path of electroman's implication, and the additions from some other comments as well.

As Michael Farady taught us over 170 years ago...

...the corrosion of metals is (primarily) an electrochemical action. Iron, in nature, LIKES to exist at a much lower level of (Gibbs') Free Energy. Thus, it is found in its oxide form. To make it useful to us, we must not only add other constituents to it, but we must pump additional energy into the new crystalline structure in the process.

After being put into service, most structural steel (if not adequately coated and/or cathodically protected) tends to "give-up" that added free energy via the process of corrosion. Then, being in its oxide form again, re-refining is required to restore full usefullness.

As previously stated; addressing the original (verbatim) Q: for each different material ("corroded"), there would be a different reverse-corrosion mechanism.

Register to Reply
Guru
United Kingdom - Member - Old New Member

Join Date: Jul 2005
Location: South east U.K.
Posts: 3538
Good Answers: 92
#25

Re: Reverse process of a Corrosion

08/13/2007 5:23 AM

As has been mentioned in some other posts the opposite of corrosion is reduction. If parts are held in an oxidising atmosphere you will get some degree of oxidation. If these parts are then held in a reducing atmosphere (usually with some heat) the oxidation will be reversed. Generally the reducing atmosphere will be one that excludes oxygen & is usually rich in hydrogen. The application of heat promotes the consumption of the oxygen held in the oxides (I'm not a chemist so I may not have explained this too well). Unfortunately this cannot re-attach oxides that have flaked off.

__________________
I didn't have a really important life, but at least it's been funny (Lemmy Kilminster 1945-2015)
Register to Reply
Guru

Join Date: Jun 2007
Posts: 1035
Good Answers: 40
#28
In reply to #25

Re: Reverse process of a Corrosion

08/13/2007 10:21 AM

Whilest correct insofar as the effect from exposure to a reducing atmosphere, I beg to "nit-pick" the first line ~~~ Re-read paragraph 3, post 18. Reduction is the opposite of, mirror-image of, or reverse of Oxidation (specifically), not corrosion (specifically). For a metal to experience corrosion, both Reduction & Oxidation must occur simultaneously.

Using steel as an example, the material is NOT truly homogenous. There are both anodic and cathodic sites littered throughout any plate, pipe 'what-have-you' made of steel. When one of the anodic sites decides to "give-up" an electron ("oxidation"), that electron must be taken-up by an adjoining cathodic site on the steel. The oxidation reactions on said piece of steel can ONLY ... repeat ONLY take place at the rate of consumption of electrons in the cathodic reactions, or reduction (period).

Said corrosion reactions (REDOX reactions) will only occur given the right environment, which must include an electrolyte. As previously mentioned, there are 4 mandates required for a metallic corrosion cell to exist (Post 18). Eliminate any *1* of those 4 mandates, and you eliminate corrosion.

Thus, eliminating the electrolyte from the "circuit" (by sufficient coating), you eliminate corrosion. Eliminating the "differences" between anodic and cathodic site potentials (which is what we do with cathodic protection of steel), and you eliminate corrosion.

Without rambling any further, "ANODIC" protection does NOT perform the same function as CP (Cathodic Protection). Anodic protection is applied to Stainless steels and other alloys that develop a passive film for corrosion protection. Anodic protection uses a working cathode to help maintain the integrity of the passive film in the presence of extra-aggressive electrolyte solutions.

"Lest we lead others astray...." ~

Register to Reply Score 1 for Good Answer
Guru

Join Date: Jul 2007
Location: UK, Midlands
Posts: 515
Good Answers: 2
#26

Re: Reverse process of a Corrosion

08/13/2007 5:36 AM

I thought there was a process by which, for instance, tarnished silver could be restored chemically/electrically.

If not we should invent one forthwith for the preservation of old relics, before I get any older.

__________________
Wish I was here more often.
Register to Reply
3
Guru
United States - Member - New Member Technical Fields - Education - New Member Popular Science - Cosmology - New Member

Join Date: Dec 2006
Location: Boca Raton, Florida
Posts: 576
Good Answers: 13
#29
In reply to #26

Re: Reverse process of a Corrosion

08/13/2007 2:52 PM

I thought there was a process by which, for instance, tarnished silver could be restored chemically/electrically.

Yes, you can easily restore silver by the electrochemical reduction of the tarnish layer (which consists mainly of silver sulfide, Ag2S). I've done it myself. Just take a glass or plastic container, line the bottom and sides with aluminum foil, fill with distilled water, add about two teaspoons of ordinary salt per liter/quart of water, add the same amount of baking soda (sodium bicarbonate), dissolve, and finally completely submerge the silver object in the solution. Make sure that the silver object makes good electrical contact the the aluminum foil. Aluminum donates electrons to reduce silver sulfide back to silver metal. In the process, some of the aluminum metal converts to a colloidal white solid consisting mainly of aluminum hydroxide and a trace of aluminum sulfide (safe to handle and flush down the drain). Sometimes the restored silver layer appears a bit chalky and dull white. If so, rubbing with a soft cloth usually brings back the mirror shine.

__________________
Problems worthy of attack prove their worth by hitting back. -- Piet Hein
Register to Reply Good Answer (Score 3)
Power-User

Join Date: Jun 2006
Location: Birmingham, Alabama, USA
Posts: 313
Good Answers: 7
#27

Re: Reverse process of a Corrosion

08/13/2007 10:06 AM

Aw, come on folks. The opposite of corrosion is smelting. And yes, it does occur naturally, when metal oxides melt along with other rocks inside the the earth.

Bill

__________________
Bill Morrow
Register to Reply
Guru
Engineering Fields - Piping Design Engineering - New Member Egypt - Member - Member since 02/18/2007

Join Date: Feb 2007
Location: Cairo, Egypt
Posts: 1734
Good Answers: 244
#30

Re: Reverse process of a Corrosion

09/04/2007 7:59 AM

Corrosion = Oxidization.

Reverse process of Corrosion = Reverse process of Oxidization.

Now, What is the reverse process of Oxidization?

__________________
It is better to be defeated on principles, than to win on lies!
Register to Reply
Guru
Engineering Fields - Piping Design Engineering - New Member Egypt - Member - Member since 02/18/2007

Join Date: Feb 2007
Location: Cairo, Egypt
Posts: 1734
Good Answers: 244
#32
In reply to #30

Re: Reverse process of a Corrosion

03/06/2008 6:15 PM

Reduction is the reverse process of oxidization, so reduction is the reverse process of corrosion.

__________________
It is better to be defeated on principles, than to win on lies!
Register to Reply
Anonymous Poster
#33
In reply to #32

Re: Reverse process of a Corrosion

03/06/2008 6:37 PM

Here is a thought for the day:

how bout reading all the posts already placed above before opening mouth and inserting foot...?!

Register to Reply
Guru
Engineering Fields - Piping Design Engineering - New Member Egypt - Member - Member since 02/18/2007

Join Date: Feb 2007
Location: Cairo, Egypt
Posts: 1734
Good Answers: 244
#34
In reply to #33

Re: Reverse process of a Corrosion

03/07/2008 3:02 PM

how bout reading all the posts already placed above before opening mouth and inserting foot...?!

1st. We all are not here for exam.

2nd. Knowing the reduction as the reverse of oxidation is not requiring an expert, but any child at primary school can answer that question.

3rd. Please refer to my posts to evaluate my participations and my experience.

4th. I don't like your speech and I think there is only one here to insert a foot inside his mouth, because he is unknown person under name of Guest, post 33.

__________________
It is better to be defeated on principles, than to win on lies!
Register to Reply
Power-User

Join Date: May 2007
Posts: 225
Good Answers: 4
#31

Re: Reverse process of a Corrosion

03/06/2008 7:20 AM

it depends on the type of corrosion....

if it's just an oxidation then is reduction..

if it's a Stress Corrosion, erosion-corrosion, intergranular corrosion and so on then is not easy to give you an answers...

S.

http://www.corrosionist.com

Register to Reply
Register to Reply 34 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Abdel Halim Galala (3); agua_doc (1); Andy Germany (3); Anonymous Poster (2); bmorrow492 (1); Del the cat (2); Electroman (1); Labyguy (1); mareng (2); ndt-tom (3); Nigh (1); omw7 (1); Pepper (3); sail4evr (1); strider6 (1); svengali (3); TexasCharley (1); TVP45 (2); Wrenched (2)

Previous in Forum: Which MCU Processor Is Used On CFM56-5B Engine's ECU?   Next in Forum: HVAC cooling tip & Question

Advertisement