S22. Heat Treatment
S22.1 Test specimens shall be heat treated together
with the castings they represent. Heat-treated specimens
shall be tested and shall meet the tensile and impact properties
specified.
S22.2 The remaining test specimens from Supplementary
Requirement S22.1 representing the casting shall be
treated thermally after the final (foundry) heat treatment
to simulate heat treatments below the critical temperature
that the casting may receive during fabrication, and then
tested for mechanical properties. Time, temperature, and
cooling rate shall be as stated in the order. In the case of
postweld heat-treatment, the total time at temperature or
temperatures for the test material shall be at least 80% of
the total time at temperature or temperatures during actual
postweld heat-treatment of the fabrication of which the
casting or castings are a part. The total time at temperature
or temperatures for the test material may be performed in
a single cycle. When this Supplementary Requirement is
specified, the welding qualification test metal must be processed
in the same manner.