Welding Distortion Explained Part 1: Principles

[@thomasherbig]

Fantastic. This is top notch: clear but not dumbed down. Thank you.

[@anengineersfindings]

Glad if you like the content, thanks.

[@johnmcnamara3719]

Greetings from Australia. Every now and again you stumble on an engineering giant that carefully crafts the sharing of knowledge in a clear and precise manner. Thanks to Stefan Gotteswinter for the heads up. I subscribed to this Chanel immediately. And look forward to further updates. Thank you Alex.

[@anengineersfindings]

Glad if you find the video's content helpful. Thanks for your kind comment!

[@spike60735]

This video series are just really well made, thank you for offering that sort of knowledge for free!

[@anengineersfindings]

You're welcome, glad you find the videos interesting.

[@gcmarcrod]

What a brilliant and informative vidio

[@bradthayer6782]

Very clear demo, thanks! Now I understand why cast iron must be pre-heated before it is welded. Since it’s not ductile, the strain would be quite bad without pre-heating.

[@anengineersfindings]

Right!

[@S_Rios]

So you teach at TUM! That explains a lot. Fantastic video. Thank you very much!

[@austinsmith2756]

This is exactly what I was looking for! Hammering, clamping, and weld sequence are all my current job uses. Gaining an understanding above that will set me apart from all the other welders in my shop. Being able to introduce this heat treatment technique will be a game-changer! Many thanks, and look forward to watching more videos

[@DudleyToolwright]

Very useful and entertaining. It must be the engineer in me that loves data.

[@zoozolplexOne]

Thanks for sharing, clear explanations

[@warrenjones744]

Well done sir. excellent explanation of the principles. On to part 2

[@OldIronShops]

my grandfather was a welder and was a genius with flame straightening. once he was asked to fix and train dock edging that had to be + - 1/16" . the part that complicated this was that the train graded in to the platform and it was also curving so the edge was a enormous helix. his boss told him they never would have gotten it with out him. excellent video cant wait for the others.

[@anengineersfindings]

Very impressive, the story of your grandfather. I find that people tend to forget that the modern world we live in was made pretty much without computers, CNC-machines or 3D-printers. Rather it was made by excellent craftsmen and smart mechanical machinery. The other three parts of the series are coming in the next few days, I hope you will find them valuable. Thanks.

[@OldIronShops]

@@anengineersfindings another interesting story was that when he first started they still used Star tip hand hammered drills to install concrete anchors. This was maybe 1960 or so

[@zekecook6586]

Thank you, that was terrific! Nicely done.

[@beachboardfan9544]

What fab table is that? Looks great!

[@ronhuffman7973]

Great information!

[@uncledoug9999]

Great series!

[@donaldcope]

As ever, fantastic video Dr.-Ing. Fillafer! I'm really looking forward to the upcoming series segments.

[@anengineersfindings]

Thank you, Sir. The remaining three parts will be online in the next few days.

[@bobvines00]

Alex, since experiment sample #1 increased its thickness, I have to assume the there is a ring around the "thicker" portion that is now thinner that it was. The thicker material has to come from somewhere! Thank you for a very interesting video -- I'm watching all of your older videos now because they are very interesting. ;) And I started my professional life as a Mechanical Design Engineer a long time ago, so _everything_ you discuss is very interesting to me.

[@anengineersfindings]

Mr. Vines, what you say about the thinned ring around the thickened spot is perfectly true. I don't show this in the video because the thinning is narrow and not so straight forward to measure. Thank you for your kind comments, glad if you find my videos interesting.

[@beachboardfan9544]

28:20 Is there a distortion perceptibility material list? I'm curious to know whats at either end of the spectrum...

[@av0wvos]

I don't know if it would be exact, but a table of thermal expansion coefficients would probably get you close.

[@richardallan455]

Hi ,thank you well explained ,interesting content I cannot wait for more ,I am a Welder and without proper welding sequences heat input and a whole lot more materials expand ,buckle ,warp so well done .

[@sergiofernandez664]

Thank you very much professor wonderful explanation ¡¡

[@SkylerOlsen]

Great presentation. Thanks for sharing!

[@MuellerNick]

Excellent! Thanks a lot for your efforts!

[@raymondpeters8106]

This is amazing! Thank you so much!!

[@Hydro1738]

Excellente video... !!!

[@somebodyelse6673]

Strange how little information is available on a process so vital to modern fabrication. The welders I know, have all developed an intuition for managing distortion, but no formal instruction on the principles. I am also hopeful your press project is going well!

[@anengineersfindings]

Sir, I fully agree. To my best knowledge, even the very extensive welding textbooks can't provide much practically useful information on how to control welding distortion. I hope this four part video series will be of value for practical welders or advanced welder education. The remaining three parts I will post in the next few days. The press brake is finished since about two months, I will probably make a video of it's build and characteristics soon, since it seems to be of general interest.

[@stevecanny1583]

Awesome video Alex, I'm following with great interest! :)

[@anengineersfindings]

Thank you, Sir!

[@Gottenhimfella]

13:07 Surely any residual stress in the central spot would be tensile, not compressive? it is, after all, trying to shrink the surrounding panel. In which case, the sign of that stress would be the opposite of the sign of the stress creating the thickening, so it seems to me that thickening resulting from plastic deformation under compressive stress would be REDUCED by the residual stress, not increased?

[@anengineersfindings]

It seems to me that you confuse the terms "residual stress" and "stress" in general. The thickening of the heated spot happens while you heat it, so responsible for it are stresses, or more precisely "Eigenstresses" (stresses which are not caused by external mechanical forces). These stresses change during cooling, i.e. the sign inverts. The stresses which remain after cooling (and after plastic deformation has happened) are called residual stresses. Hope this answers your question. You might find part 2 of this video series helpful for understanding this, there I show with a mechanical contraption how stresses develop during heating and cooling.

[@Gottenhimfella]

@@anengineersfindings I'm puzzled. Which of the specific claims in my comment suggested to you that I misused the term "residual stress"? Maybe my language was unclear somewhere, because your reply seems to confirm my understanding to be correct.

[@shedfullnow2007]

hi thanks for this looking forward to the rest, btw how is the press build going ?

[@anengineersfindings]

Thanks, I finished the press brake about two months ago. Since this seems to be of general interest, I will probably make a video of it's build and characteristics.

[@TorteTS]

Great content. Why the subsequent shrinkage cannot compensate this increase in thickness? What is the correlation between radial and axial shrinkage?

[@anengineersfindings]

The subsequent shrinkage does not compensate for the thickening, because this is not a forward and back kind of behavior, but rather a forward, sideward and backward one because of the plastic deformation. Radial and axial shrinkages depend on the shape of the object. A sheet behaves different that e.g. a cylinder. Or think of the experiment with the heated spot at the corner, here also the local "shape" influences the (thickening) result.

[@albizeta5674]

Is it reasonable to say that occurs also a change in length of the square sides ?

[@av0wvos]

A good question. I think the plastic defamation would be localized to the high temperature point in the center of the square. The rest of the square should expand and contract by the same amount producing no permanent change.

[@andval256]

greats videos. too bad you don't create more content about welding

[@anengineersfindings]

Thanks, and sorry, but another content opportunity for welding stuff will surely come along. At the moment I'm busy with a lot of customer work of which I am not allowed to show interesting things, sorry.

[@MachinistGuru]

Is the welding table your own creation? It's impressive!

[@anengineersfindings]

The welding table in the video is a commercially available one from a German manufacturer (Siegmund). It is nice, but some features of it I don't like very much.

[@MachinistGuru]

@@anengineersfindings Well, I for one would definitely be interested in a video about it. Thank you for the content.

[@bobvines00]

@@anengineersfindings Alex, could you touch on the pros & cons of the welding table in a future video, even if that's only a small part of a longer video?

[@anengineersfindings]

Sure, I'll try to cover this in a future video. Currently I am building a welding table from a wartime surface plate, so this is right on topic. Thanks.