UNS refers to a specific unification number assigned to a metal. For example, ASTM A 213 T22 refers to the product form, how it is made, minimum mechanical properties. The T22 actually has a UNS alloy designation, this is UNS K21590.
There are cross references located in the back of the UNS book. Have you looked at those? They include ASTM and SAE among others.
BTW, ASTM specifications are ANSI standards.