Examinations and Tests of Fractured Steel Plates Removed from Welded Ships

摘要

This report covers the examinations of samples from 8 fractured ships received between April 1, 1950, and March 1, 1951, and laboratory investigations of 13 plates selected from these samples. Preliminary examinations of these samples and preparation of test specimens are in progress, and results of some of these preliminary examinations are discussed briefly in connection with their similarity to previous failures. A different method of analysis of the accumulated data for transition temperatures of source, thru, and end plates, by the use of percentage frequency diagrams, is discussed and illustrated. The method of calculation of the probable maximum transition temperatures of the plates from their chemical compositions and fracture grain sizes is illustrated in a table, and the calculated maximum and the observed transition temperatures of the plates are compared. The method used for determinations of the fracture grain size is described.