Ball, Leslie W.
Naval Ordnance Lab., White Oak, Silver Spring, Md.
Pages: 5 Published: Jan 1950
The Bureau of Aeronautics recently has authorized the Naval Ordnance Laboratory to make a new attempt at setting up specifications based on the establishment of standard types and grades of discontinuities as shown by radiography. It is for tackling this task that we recommend a revised procedure for establishing radiographic standards. All previous papers by this author on the subject of establishing radiographic standards, and most papers that have been given on this subject by other people, have been dominated by their technical content. Experience in trying to establish specifications containing radiographic standards has shown that these technical contributions are rather like an assortment of building blocks which cannot simply be fitted together to form a useful structure. These building blocks include the standard terminology that A.S.T.M. Committee E - 7 has established, the clear identification of radiographic images by X-ray micrography, and the correlations between strength and radiographic appearance for certain defects and materials. Particularly for aircraft castings, it has become evident that we will never have a satisfactory specification of radiographic standards unless we have an administrative framework upon which these technical bricks are placed to form a complete structure.
Paper ID: STP47342S