The problem with tempering and cryo is that tempering stabilizes the retained austenite preventing it from being transformed to martensite. There is some danger in going directly from quench to cryo as far as cracking so some will 'snap temper' but that must be done at a fairly low temperature such as 300F.Higher temperatures such as 400F will definitely stabilize the austenite.My suggestion would be to quench, snap temper at 300F for 1 hour , cryo,10 hours would be more than enough, then double temper.
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