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Inclusion Counts, ASTM E45, AMS 2300:
"Most metallic materials have some form of inclusion content. In steels, for example, nonmetallic inclusions exist in the form of compounds such as manganese sulphide. Inclusion counts are performed to assess their type, shape, quantity and distribution (ASTM E45). Cleanliness of materials can be an important factor in many applications and current high quantity steel-making processes ensure that inclusion content is kept to a minimum. The presence of inclusions in a material can be used to determine the rolling direction of a plate. Three mutually perpendicular axes are polished and examined. Inclusion stringer direction can be used to assess the direction of rolling. Certain bearing and/or aerospace applications may require a "frequency / severity" determination of inclusions per AMS 2300. This requires a specific test specimen to be machined, hardened, and inspected by wet magnetic particle technique."
