If the ONLY concern is the steel, some Norincos are tough as nails. Tougher than Colt steel? That I'm not sure about. Tougher than Springfield or Caspian (or Ruger for obvious reasons), yes, probably.
There is a reason that the big 1911 smiths have a short list of frames they'll build on. There's a very small amount of variation in what frames will be accepted, but the name at the top of the list is always the same: Colt. Colt steel is very, very good.
That's a pretty small part of what makes a 1911 good, though. Frame geometry is a lot more important than the steel. Are you better off with a Norinco or a Springfield TRP? Definitely the Springfield.
Also, any 1911 will get wrecked if you use cheap or worn-out springs. And Norinco springs really can't be trusted. If you keep up on the spring maintenance, even a cast-framed Springfield GI should run for 50,000 rounds. The ability of the gun to handle +P really relates to spring selection more than anything else. If you make bad decisions about the springs, the gun will break.
Furthermore the first place you're likely to see failure from hot loads is not the frame or slide, it's the barrel link and slide stop. And it'll shut the gun down. So a gun with quality small parts will run longer with hard use than a gun with cheap small parts.
If you factor in the quality of the machining in addition to the steel, and the small parts, and barrel fit (which also plays a significant role in 1911 longevity) there's pretty much only one answer, and it's the only company that actually has the plans: Colt. Everybody else - EVERYBODY - is using reverse-engineered geometry based on the Colt. Some do it well and some poorly, but Colt has the plans AND they do it well, in very high-quality steel.