One of the early shops I worked in while still in school had the job of wheel maintenance for a local foundry (Tyler Pipe) where they have many local rail units transporting iron all around the place. I have turned/reclaimed a few of those wheels. It takes patience when your speed is limited to 1-3 RPM, but it's not a bad gig. Sometimes we repaired the bore as well, by metalizing, bushing/sleeving, or welding and re-boring. Lots of big hot chips.
Another heavy in that industry is Trinity Industries. They build everything but the track. On I-20 I see a great many truckloads of raw wheel forgings as well as finished wheels. Seems like also in Corsicana there is also a depot or shop with hundreds stacked around the plant. Lots of this industry still onshore.
That's hot rotary forging. Lots of the larger oilfield tools start life that way. Sometimes it's cheaper to forge it down if there is a large difference in the largest and smallest diameters of a part. Better than bucketloads of time and chips. I used to buy forged pieces for the larger driveshafts used in downhole mud motors. Only thing against them is lead time, and if you happen to make a boo-boo, it's hard to get just one more.