This specification establishes maximum permissible limits for elements not normally specified but which may occur in trace amounts in wrought nickel, cobalt, and iron alloy products.
Control provided by this specification has been used typically for highly-stressed rotating parts, such as turbine discs, where control of trace elements is required to maitain elevated-temperature tensile, stress-rupture, creep, and low-cycle fatigue properties, but usage is not limited to such applications.
It is intended that this specification be invoked only for selected applications by stipulation on drawings, purchase orders, or other documentation supplementing the material specification, or in material specifications.
