ABSTRACT
Most wrought alloy compositions are also available in an equivalent grade
casting. In addition, there are many alloy castings available in compositions
that are not available as wrought materials. This is the result of the design
freedom associated with the various casting processes. The compositions of
many cast grades are modified relative to their wrought equivalents to take
advantage of the casting process because little or no mechanical working of
the cast component will be necessary. Because of this ability to modify the
alloy compositions of the cast grades, improved and unique properties may
be imparted to some cast alloys compared to their wrought equivalents.
Various alloy designation systems have been developed to separate the
wrought alloys from the cast alloys because of the variations in compositions
and the resulting variations in physical and mechanical properties. Three
designation systems are presently used for the identification of alloys:
Unified Numbering System (UNS), Alloy Casting Institute (ACI), and
American Society for Testing and Materials (ASTM).
