I used 440C on some of the original Argonne Assaults. . . Please forgive me. . .they were for amphibious assault and jungle warfare and their top priority was rust resistance.
Also Vasco Wear, Stellite 6K, 0-1, A-2, D-2, I probably used more D-2 than any other maker out there except for Bob Dozier who is now actually made out of D-2
---in fact I still have over 18,000 lbs of D-2 in my old shop along with approx. 14,000 lbs. of A-2. I never have to worry about that building blowing away! Also, ATS-34, 154CM in the late 80's when you could only get it in 3/16" thick, very narrow bars 1.25" wide I think), BG-42 sometime between '89 - '91 . . . long before anyone else had used it, that I'm aware of., Homemade Damascus (0-1 and 1018), some other exotic steels I'd have to look up to remember, including a Maraging Cobalt/Nickel "350 Vasco Max" or something like that. . . .Weird stuff, you simply baked it at 900 degrees for 9 hours and it would harden out at 58-60 Rc with no chance of rusting. . . NONE!
I was very fortunate in the steel department mainly due to the fact that Koncor industries is within 8 miles of my shop and they are, or were, a division of Latrobe steel and I believe Crucible. I knew the guys at the plant pretty well, so I got a shot at anything new that came in.
I would constantly go there in search of the perfect steel. . .But I could never seem to find exactly what I was looking for. . . . . .back then.
Happily, I haven't been there since 1997!!!
Jerry