Basic Welding Knowledge For Engineers 1

[vocala]

Eng student interviewing at a metal fabricator. They have a welding questioner. What basic welding knowledge should an engineer have? Haven't learned much in school.

All I've learned is weld symbols and the weld size should be the same as the material thickness. If the weldment has multiple thicknesses then the weld size should be the same as the thinnest thickness.

When skip welding, how do you determine the weld and skip lengths? How do you determine when to use multiple passes? Anything else a engineer should know?

Thank you

 

[dik]

There's a bunch more than just that... an excellent site that keeps sending me articles on welding is

https://weldinganswers.com/inspection-before-during-and-after-welding-is-critical/

that's just one of their articles... they have a lot more. You might look into taking a course or two at a local college or tech school... I've learned more about welding in the last three years than I did in the 50 years that preceded that...

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[3DDave]

Start with the Lincoln Arc Welding books. They aren't modern but they are inexpensive and the big blue one deals with the stress analysis required to answer questions about welding, which is the main driver for weld size and for such as skip welds.

If they are looking for a welding engineer you may be doomed. You need decent experience in metallurgy to come even close.

If they are trying to ensure you can read what the weld is so you can have an intelligent conversation with the welders, then the Lincoln Arc Welding books will also help with that.

https://www.jflf.org/SearchResults.asp?Cat=81

Design of Welded Structures is the big blue book. $25.

I would probably also order

METALS AND HOW TO WELD THEM $15.

Both are handy to have.

Best of luck.

 

[3DDave]

Also look at the

https://www.lincolnelectric.com/en/Education/About/MyLincoln-Education-Portal

It appears to be free.

It's a program to maximize the success people have with welding so that Lincoln can sell welders and supplies with the key being success with welding. They compete with a few other makers, such as Miller, so check them out as well.

 

[kingnero]

All I've learned is weld symbols and the weld size should be the same as the material thickness.

Depends on the application. Not so if the base material is thicker than calculated for other than structural reasons.

If the weldment has multiple thicknesses then the weld size should be the same as the thinnest thickness.

Weld size should be determined based on the thinner part. A double sided weld will have a smaller leg length than a single sided weld on the same part.

When skip welding, how do you determine the weld and skip lengths? How do you determine when to use multiple passes?

By calculation

Anything else a engineer should know?

I'd be happy to know if a new guy at a fabricator's has an idea about the different welding processes, the up-and downsides of each process, the application (you can't weld uphill with an SAW installation!), the typical deposit rate of each process, a (basic) knowledge of the what, where and why of heat input, preheat and PWHT, the applicable codes (both structural and welding related), the base materials (does the fabricator only uses A36/S355 or similar, or are high-strength steels also relevant? What are the major structural differences, and how to treat them in the workshop? ...), in case of a fuck-up, how do start with a repair procedure, do you know what NDT is, show some of your draughting examples, and so on and so on and so on

 

[DrZoidberWoop]

If you are entering the "Civil" side of engineering, AISC Design Guide 21 is nearly everything you will need to know. You'll learn the individual calcs as you progress.

If you are going into the "Mechanical" or "Aerospace" side of things, it will be much more industry specific.

 

[capntom62]

I work with a lot of younger Engineers and you are not alone. Unfortunately, the knowledge to "join" pieces of metal together ranges from the DIY'r with a Harbor Freight welder in his garage to the Aerospace or Navy Nuclear welder. The knowledge and experience is never given enough credit.
There are many "best practices" to be thrown around but at the end of the day, most of your answers will come from the welding codes that are invoked by the design.

Keep an open mind and learn as much as you can in the field you are heading to.
Don't ever assume that there is a "quick" answer to a welding question.

 

[gtaw]

Look into ASME' course "Practical Welding Technology". An upcoming class is in November if I remember correctly. They have a website for the "short courses" offered to the public.

Best regards - Al

 

[drawoh]

vocala,

The big-picture summary of welding is that it is not very accurate, and that weird stuff happens when you weld anything other than cold rolled steel. [ul]
[li]Ask your fabricators what tolerances they can achieve. As a student or junior engineer, you cannot be expected to know everything. You do need to demonstrate that you can listen, and learn.[/li]
[li]Understand that welders managing temperature watch the colour cold rolled steel glows at. This does not work on materials that melt at temperatures below red heat. Definitely this includes aluminium.[/li]
[li]If your material is heat treated or work hardened, it won't be heat treated or work hardened in the heat affected zone[ ](HAZ) after welding. Again, this definitely includes aluminium. Your stress analysis should be based on annealed strength.[/li]
[li]Cold rolled steel can be welded by any idiot, except me. For other materials, including medium carbon steels like chromalloy, and aluminium, anticipate that the welding will be done by a better trained, more skilled and expensive worker.[/li]
[li]Make sure there is room for your welding equipment around your weld.[/li]
[/ul]

--
JHG