Any 400 series can be hardened, useable maximum for 440 is ~58HRc, the lower grades have less hardness. The more you harden the less corrosion resistance you can expect.
As for other material, 440C has gotten very expensive as of late, try to stay to lowest grade that hardens to desired range.
I would not expect a satisfactory outcome in induction hardening 440C. Normal practice is to preheat this material prior to austenitizing to avoid cracking.Trying to induction harden to obtain a hard surface will most likely set up thermal and stress gradients that will lead to cracking.
440C is usually through hardened. The transitions between hard/less hard portions can have very poor properties. If you want hardness variations you can try two things:
Harden the whole part, but use differing quench rates to get different reuslts.
or harden the whole part and use differing temper temps to get different resutls.
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Rust never sleeps
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