Talk:Galling

Original research

This looks more like a dictionary entry. Should it be here, or in wiktionary? Motor 03:01, 16 Mar 2004 (UTC)

I think it just needs expanding and/or merged with some more appropriate article. --144.131.67.249 13:41, 10 October 2006 (UTC)

I plead guilty to original research in this case. I just removed the following paragraph, and replaced it with my own explanation of galling as a cold welding phenomenon:

Galling can occur when metal parts, such as the threads of nuts and bolts, are forced together and rubbing generates friction between surface asperities. The friction causes heat, which is mainly isolated to these asperities. The asperities weld together but further displacement causes these tiny welds to break, which makes the surface even rougher, creating more opportunity for friction. Galling should not be confused with cold welding.

The friction welding explanation does not match my own observations, see the main article for more details. Unfortunately, I have never found a credible source discussing galling, so I have no references to offer.--Yannick 01:06, 20 May 2007 (UTC)

I myself am an active researcher within the area of tribology, with particular focus on wear in sheet metal forming, which is often related to galling. Very often in text books, galling is used as a term describing cold welding, scuffing or severe adhesive wear for metals with no emphazises on that the metals should be a certain Fe-alloys or a pure element such as Al, as the previous author described. Generally, these materials materials are more suspectible to galling, but indeed other metals suffer from galling as well. The statement that carbon-steels do not suffer from galling is incorrect, which has been shown by several researchers including myself. If this was the case, than the automobile industry, as an example, should have no need for the use of press-lubricants during forming of carbon-steel components. But this is of course not the case.

However, the definition of galling as a single event, or wear mechanism, is very rarely used. Rather, most authors, including myself, use the expression to describe a wear process, composed of several regimes and wear mechanisms. A short description is the following: Initially when two surfaces are brought into contact and slid relative each other, a regime of mild wear is initiated, meaning that transfer of material from one surface to the other will occur. Generally material transfer occurs from the softer surface to the harder surface. This regime will continue for some sliding distance, depending on the loading, temperature, materials etc. The continuous pick-up of material on one surface localizes the contact, leading to a concentration of the contact pressure which subsequently localizes the areas of where material transfer occurs. Therefore, lumps of transferred material will grow in certain areas, which at a certain lump size initiates the entering into the second regime, where scratching of the counter-surface by the lump initiated. Generally, the lump hardness is increase by strain hardening and oxidation phenomena, which makes scratching possible. In this stage, the metal forming industry often starts to notice the phenomena of galling, since scratches begin to be visible on the formed parts. If the sliding is allowed to continue, at least in un-lubricated conditions, scratching will transfer into severe metallic adhesive wear, cold welding or scuffing etc, which is related with very high friction and possible seizure of the tool and work material. /Anders

If I understand you correctly, you're saying that the former friction-welding definition is closer to the truth than my cold-welding definition currently in the article. And yet this doesn't match my practical experience, which is that galling happens exclusively to corrosion resistant metals, and preferentially to similar mating materials. For example, even a 304 / 17-4 pair will gall less than either of those materials gall with themselves. I've found a weak web reference [1] which might make us both right. According to this, the mild wear regime which you describe will only occur after the oxide surface film has broken down, which of course is thinner on corrosion-resistant metals. Once that happens, material similarity would accelerate asperity accretion since it essentially becomes localized cold-welding. That will rapidly take us to the second regime where all the visible scratching occurs.

In other words, the mechanism you explained is universal, (and may apply to carbon steels in unusual situations which I haven't seen,) but it is greatly magnified by cold-welding in corrosion-resistant metals. Is this a good technical basis for a better definition of galling?--Yannick 04:37, 31 August 2007 (UTC)

What about the role of load in galling? Surely the mild-adhesive wear regime could be bypassed if loads are sufficient. After all isn't this the idea behind the ASTM test for galling? —Preceding unsigned comment added by 71.234.236.251 (talk) 04:53, 1 January 2011 (UTC)

Thermological explanation of galling

Hi. I´m responsible for most of the text regarding the galling phenomenon presently found in the Wiki archive.

My opinion of the galling phenomenon is the following. Galling is highly connected to thermal or pressurized influenced contact and the interaction between the mating surfaces.
The temperature or pressure around penetrating objects is higher for small and sharp objects compared to larger blunt objects due to higher acceleration. This means that phase transition can take place even in the initial build up process and onset of adhesive material transfer and galling. It was clear that a change in material behaviour, which increased resistance for further advancement, took place around sharp edges even in the build up process where attached material was insignificant. My conclusion, there is a connection between the attached material and the geometrical situation around penetrating objects and developed pressure and temperature in the contact zone.
The theory about electrolyte and a galvanic exchange is interesting but in my research using a SOFS (slider-on-flat-surface) tribo-tester, revealed a clear difference between exhibited contacts found in the tracks after testing. An electrolyte and a galvanic exchange should always be present, which was not observed using the above equipment.

If you are interested in the argumentation read the reference and perhaps include it as a reference in the Wiki text about galling.

• A scientific report on galling and friction, Full text [pdf], [2], Harald Wallin, Karlstad University, (2008), 1-129, An investigation of friction graphs ranking ability regarding the galling phenomenon in dry SOFS contact: (Adhesive material transfere and friction), Link: http://www.diva-portal.org/smash/record.jsf?searchId=1&pid=diva2:37573 —Preceding unsigned comment added by Haraldwallin (talk • contribs) 16:06, 17 November 2008 (UTC)

Category:Welding

The galling phenomenon is not really a type of welding process but the same mechanism, "concentration of energy", is involved in both friction welding and cold welding as in galling.

The above text was in the article and really belongs here for discussion. The author of this comment might well be correct that the welding category should go. Wizard191 (talk) 17:51, 24 July 2009 (UTC)

Sorry about that. I thought it was god idea to explain the difference between welding and material deterioration. Galling is a wear process and friction welding is a manufacturing process. Booth include concentration of energy which in this case means kinetic energy (acceleration of deformed material), pressure and heat. Acceleration of deformed material is a prerequisite to develop a contact pressure of any sort, in fact all developed forces include acceleration even the gravitational force. --Haraldwallin (talk) 22:00, 18 October 2009 (UTC)

Electrolytical explanation of galling

Could it not be that because when the oxide layer is removed and there is a electrolyt present that ther is a galvanic exchange in metal and that is why the bounding occurs? Willems.stijn (talk) 04:37, 18 January 2008 (UTC)

Location of galling

Why is no mention at all made of thread galling ? Its one of the most common places for galling to occur and certainly the most likely place that anyone outside of the sheet metal forming industry would encounter it. As a result I believe it actually deserves a special mention in the opening paragraph. But to not even mention it at all when one of the two references used in the article deals with it specifically is a travesty. —Preceding unsigned comment added by 124.169.218.140 (talk) 06:37, 5 September 2010 (UTC)

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It´s a travesty to complain, and do nothing =)

I suspect that your generall intention is only to mention my name in an unfavourable manner, which is against wkikpedias generall purpose.
If you want to be a bully you can use faacebook or flaschback as everybody else. However, if you are serious which i strongly disbelieve, you are free to add anything that make the galling page better.
Because I do not have suprimousy over wikipedia, but if I´m right, I´m right, and you can´t do anything about that LOL =)

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No, my intention was\is to improve the article. Which I did and then subsequently saw removed with no explanation. There's no point in making trying to make any changes to the article if you are just going to jealously remove my contributions, I've got better things to do than get into a revert war. I even went to the trouble of finding a relevant reference only to see you use it for its discussions of 'materials likely to gall' without any mention at all of its major topic, thread galling. —Preceding unsigned comment added by 203.59.133.156 (talk) 02:08, 4 December 2010 (UTC)

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Yes you did a god jobb and many of your changes where valid and I was very impressed, they are still in the text, but you did some errors regarding the context and melody of the text and therefore I took your text and changed it slightly. Regarding your exitness over threads, you can put it in because I don´t have ownership over the wikipedia article. But make the article better and don´t vandalize or make unjust accusation, as you previously did against me LOL
Remember, this is wikipedia and you as well as I, are free to make changes and there are many who will. No offence

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OK well I think its fair to say I'm not going to be able to emulate the exact 'context and melody' that your going for here so I'll leave the specifics of it to you. Personally I think the whole tone of the article is very dry and overly specialized for a public access encyclopedia but anyway. I see that there IS now a mention of threads but it incorrectly states that galling occurs during the thread cutting operation. In fact if you read the reference I supplied properly, its during the assembly of the fasteners that galling is most likely to occur. Which is why I believe that's where the average 'wiki reader' is most likely to encounter it. I mean how many people use bolts compared to those that operate sheet metal forming equipment ? BTW Might I suggest that in the future if your going to remove a significant chunk of someones writing for any reason you at least show them some courtesy and write a few words of explanation in the edit summary? —Preceding unsigned comment added by 124.169.189.2 (talk) 02:46, 16 January 2011 (UTC)

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Ok. I apologize for not showing the courtesy to write a few words of explanation in the edit summary. I don´t know how to do it properly and politely and I haven´t written any comments previously because every body else was changing the text without any politeness or extensive comments.
And quite frankly, your original comment refers only to me regarding this problem but the problem is universal for all of Wikipedias articles and to attack only me was not very polite. Although I understand and sympathize with your request.
However, the problem with an incorrect statement that galling occurs during the thread cutting operation, are not to be found. Only thread manufacturing are mentioned.
If your browser connect to another version of the galling article, please notify me.

I hope this apology is accepted. --Haraldwallin (talk) 16:46, 31 January 2011 (UTC)

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No worries, apology accepted. Yeah that's the bit I'm talking about. I guess cutting wasn't a true synonym for manufacturing in this case since you can also roll threads. But my point was the reference deals with neither, its about the assembly of the completed fasteners.

I hope I can be excused for using mixed language between British and American English

Hi, I noticed that my use of mixed spelling between British and American English have been a source for minor exasperation.
I hope I can be excused, because "British English" is not my mother language and the subject galling, friction and thermodynamic issues are very complex subjects and the glossary are not always well established. And quite frankly, British and American English, it all sounds the same to me.

However, I tried to use an objective spelling and in detail explain and define, all used glossaries that can be apprehended as strange. Know this, galling was a very undeveloped field of science when I started to write a report based on my research done in the University back in 2006-2007 and subsequently the galling article found here in the Wikipedia archive, that I contributed to in 2008, involve much of its content. In my research, and in others, the frequent use of knew developed expressions was very common.
However, their are frequent misinterpretation and misunderstandings due to differences in opinion, understanding and interpretation of definitions. This is why I tried my best to explain all aspects of the galling phenomenon in such a essential and fundamental way as I possibly could, whit out using my own terminology.
For example, my own paper found in the references, is much more explicit and exact in distinctions between different contacts such as abrasive- and adhesive-wear and I also theoretically explain differences in the adhesive-wear regime and consequently name them based on how they operate and are manifested in differences in exhibited characteristic patterns found in the tracks after sliding.
I defined and explained my terminology in detail because there just were no standardized words available to make a useful report that following researchers could understand and learn from so that they could avoid do research based on theoretical errors.
The consequence is that the reader must go through the introduction and discussion chapter to fully understand the context and definitions that I used and make the thesis fully comprehensible and useful.

I hope this explanation perhaps solve some of the issues regarding spelling, structure and used glossary in in the text found in the wikipedia Galling article. --Haraldwallin (talk) 13:33, 28 November 2010 (UTC)

Cleanup templates

The following discussion was started on my talk page, and I'm moving it here. Wizard191 (talk) 18:50, 8 December 2010 (UTC)

Why is the galling page changed and include three different types of uninformed and out of date information? The three information banners can bee seen below: {{Copyedit}} {{COI}} {{wikify}}

I discussed the problem whit the three shown banners whit the Wikipedia live-chat service and they told me to just delete them. I now noticed that you included them again in the article, so I now humbly request to the supremacy of Wizard191 to get rid of these three inaccurate information banners or at least specify the problem in the galling discussion page, as everybody else. If you haven´t read the galling article, how do you know it´s something wrong whit it? I can assure you that everything I put the Wikipedia galling article it is extensively peer-viewed and approved at Karlstad University, Sweden.

--Haraldwallin (talk) 16:21, 8 December 2010 (UTC)

What is this "live-chat service" that you speak of? I haven't ever heard of one. The proper way to discuss the templates is here on the talk page of the article. All three are applicable because: 1. {{Copyedit}} the English needs to be improved 2. {{COI}} you have pretty much taken ownership of the article 3. {{wikify}} the article needs more wikilinks. Hope that explains it. Wizard191 (talk) 18:53, 8 December 2010 (UTC)

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Hi dude, Wazz up Wizard191, why didn´t you include my entire massege? It looks very miserable and whining, as it reads above =)

Are you kidding me?, so you don´t have a "Wikipedia live-chat service", strange because I used it, and if that isn´t possible must sombody be realy evil. No suprise to me when the whole world is bullying and abusing people who have no means of fighting back, with the exeption of trying to make it so clear how horrific the discussion, realy can be. And it is to be hoped that somewhone in the crowd of onlookers finally realize the unreasonable and unjust in the many´s bullying against an unknowing victim or potential plaintiff.

Regarding your, Wizard191, complaints quotation: "you have pretty much taken ownership of the article 3." end quotation, I can only reply that there are several others who make contributions to the galling article and I only make sure it´s scientificly correct with regards to syntax and source. Some parts have I watched extra carefully, for example the pictures because I made them and it´s therefore easy for me to correct the content and syntax of the description. Other peaople are free to write any knew exiting findings and I will not change anything as long it´s has warranty. A lot of the text have been changed by others over the years and is still present in the article so don´t blame me for something that clearly isn´t true. --Haraldwallin (talk) 17:06, 13 December 2010 (UTC)

I thought I did include the whole message, other than the greeting. If I missed something else, then feel free to copy it over; it was a mistake if I missed it. After looking through the history of the article it doesn't appear that you've taken ownership of the article. So I'm cool with dropping the COI tag. Wizard191 (talk) 19:18, 14 December 2010 (UTC)