[12V71]

I have it on good authority (Thanks to the guys over at the Hobart Welding Forum), that the angle iron is rerolled rr tracks.

https://jssteel.com/our-rail-steel-products/railroad-rails-high-strength-angle-iron/

Yep, that and certain grades of rebar that don't weld well. I had to peel a bunch of bed frame off a semitrailer that was being used as pallet stops (really) brittle and springy, when you could grab it with a big adjustable wrench it snapped of the welds clean. Of course all the welds appeared to be done with a Harbor Freight flux core welder.

Is that not bed frame angle? Get a load of the other welds. Dang sideways pic.