As always, wisely choose your axes, choose your load combinations, divide the combined stresses in their most basic components along those axes, and evaluate using the Von Mises model. Easily said, sometimes a bit more difficult to practise. But a good understanding/visualisation of those...
There is a separate audit schedule attached to the CE marking requirement (that very few USA manufacturers will follow).
Ask your client if they absolutely need the CE mark, or if a (3.1) certificate that mentions all (chemical and mechanical) specs is sufficient. Chances are, they won't care...
It means even without 3834/1090 cert, they can make machines and affix the CE marking.
MD is an autocertification system (no external control organism needed).
EN 1090 suffices (is actually obligatory) for steel work acc. to the eurocodes.
That's basically an 3834 certification with some additional bells and whistles (like work preparation, bolting, corrosion protection in addition to it).
This has nothing (I repeat: NOTHING) to do with the machinery...
Have you spoken to wire manufacturers? Some offer wire espacially made for robotic applications. I don't know what's specific in that case, though (other than the 200 kg drums).
Please share your feedback in case you find something that reduces friction and does not impede the weld quality.
Use good quality liners
Avoid bends in the wire feed. Even better, keep the wire feed as short as possible.
Use decent drive roll systems
Make sure your welding parameters are spot on. Spatter on the contact tip instantly blocks the feeding motion. If the wire kinks at that time, you're fucked...
Welding on these alloys has been widely tested and documented. I wouldn't say it's unpredictable. I would say it's generally a bad idea, as we can predict fairly accurately what's going to happen.
Here's a common assembly, rails with multiple bolts and locator pins (in hard steel), used on airplanes.
The ISO view is a detail, and doesn't show the entire part.
I know, I often spec stainless (A2/A4) if welding of nuts is required (and if there are no problems with compatibility/galv.corr). I just asked because saying "never weld on bolts of any kind" is neither realistic nor correct in my line of activities.
1. the criminal code.
2. most substrates are low alloy, low strength, like EN 10152 and EN 10346. So usually 1.1, sometimes 1.2. You'll need FM1 certificates.
+ typically the high carbon and chromium content gives ideal circumstances for the creation of martensite after welding (due to rapid cooling). You're bound to end up with hydrogen cracking.
Search for "storage and handling" info sheets from various consumable producers.
Commonly, storage < 60% relative humidity is recommended.
Ofcourse, low hydrogen rods (3.5 ml/100g) require different measures. If vacuum packaged, storage doesn't matter as long as the packs are not pierced.
If...
Train the welders, so that they make more uniform (visualle pleasing) welds?
Use rotating devices, so the welds are made in 1G?
Change weld process (if only for the cap)?
Here's an example of one of our interventions (before/after).
Is it something similar you're looking for?
Basically, if your clamping preload is big enough there won't be a bending moment on the bolts. You'll only have a bending moment if the purple mount comes loose from the surface of the table. I'd start with an energy method, as the posts will also reduce the bending moment at the base due to...
AT first sight, incorrect weld settings. Looks like not enough fusion all around the surface of the stud.
Contaminants could certainly be part of the reason, but I suspect insufficient capacitor discharge as main culprit.
Also, do you have a good spring value (the force that pushes the stud to...
In Belgium, most of the pipeline and railway welding is performed with either Miller or Lincoln power sources, with a large preference for the red machines.
Now, only the 300 and 410 A Lincoln (diesel) gensets are available on the european market. The 500 does not have the required CE marking...