For heaven's sake, we're not completely sure how Damascus steel was made, and that was done by humans hundreds of years ago, with thousands of samples lying around the world. And we're just supposed to assume that because we've tried all the combinations of alloys we can think of, there are no other possibilities? Have some imagination. Think about nano-layering and quasicrystals, to say nothing of stable-island heav…
This is different. Any example of "Damascus steel" that you can point to you can use an XRF device on to figure out the actual alloy composition. That doesn't tell you exactly how to make it, it just tells you what elements it's made out of.
Just to belabor the point some more, we didn't know until recently that damascus steel contains carbon nanotubes (probably derived from plant material). Was an XRF machine ever going to pick that up? Not in any detail, I'm guessing.
https://en.wikipedia.org/wiki/Damascus_steel
And this is all without using any imagination. If you're dealing with the question of alien technology, that's silly.