This one time, long ago when I had a machine shop... these tourists broke an axle in a borrowed van. Snapped it right off at the bearing. The Ford dealer towed them in, figure it out but didn't have one in stock. The two pretty ladies driving it didn't want to wait 4 days for it to show up, so they end up in my shop begging me to repair it. I explained in 20 different ways you can't weld up broken axles but they wouldn't hear of it they were on a deadline.
So I beveled it, welded it, annealed it, machined it back to original tolerance. And made them sign a hand written release and a promise not to go over 20 mph and only to the next town with a real axle in stock. They installed it and went down the road. I have no idea if it lasted 1 mile or 1 million miles but I got them on the road again.
you can't weld broken axles, but then again maybe so..