ASTM B796-07

1.1 This test method covers a metallographic method for determining the nonmetallic inclusion level of powders intended for powder forging (PF) applications.

1.2 The test method covers repress powder forged test specimens in which there has been minimal lateral material flow ( 1%). The core region of the powder forged test specimen shall contain no porosity detectable at 100.

1.3 This test method is not suitable for determining the nonmetallic inclusion level of powder forged test specimens that have been forged such that the core region contains porosity. At the magnification used for this test method residual porosity is hard to distinguish from oxide inclusions. Too much residual porosity makes a meaningful assessment of the inclusion population impossible.

1.4 The test method may be applied to materials that contain manganese sulfide (admixed or prealloyed) provided the near neighbor separation distance is changed from 30 m to 15 m.

The test method may be applied to powder forged parts where there has been a greater amount of material flow provided:

The near neighbor separation distance is changed, or

The inclusion sizes agreed between the parties are adjusted for the amount of material flow.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.