The X-Ray Testing of Metals at Watertown Arsenal
TESTS of metals with X-rays, as made at Watertown Arsenal, are of two classes: (a) radiographic tests in which photographic images of internal details of the gross structure are obtained and (b) diffraction tests in which images are obtained that may be interpreted to give information regarding details of micro-structure of the constituents in the metal. The present paper deals with tests in the first class. Diffraction tests will eventually result in steels that have better physical properties required for special applications in industry, but such improvement must be accompanied by elimination of defects in the gross structure of forgings and castings before the greatest utility of better steels can be realized. Radiographic testing gives pictures of defects whereby the nature of the defects can be determined, but their causes must be sought by logical deductions from other information.