Accession Number : AD0687402

Title :   MECHANICAL CONSIDERATIONS IN FRACTURE CHARACTERIZATION OF NARROW GAP WELDMENTS.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Freed,C. N. ; Puzak,P. P.

Report Date : 23 APR 1969

Pagination or Media Count : 17

Abstract : The Dynamic Tear (DT) test provides a reliable measurement of fracture toughness under limit severity mechanical conditions. In this investigation, the DT test was used to characterize the fracture toughness for a weldment of 2-in.-thick A-543 plate prepared by the automatic Narrow-Gap (N-G) welding process. The DT test specimen was modified through the use of side grooves. Fracture toughness of the weld metal was found to be dependent upon welding position; the flat (1200) and near vertical (0200) weld positions produce high upper shelf energy values equivalent to that of the plate metal, while the 0400 (near vertical) and 0600 (overhead) positions indicate a shelf level toughness approximately one-half that of the plate. Results of 5/8-in. DT tests were consistent with values from full-thickness, 2-in. DT specimens. The C sub v test produced a misleading indication of the transition temperature range and the temperature at which the upper shelf, full ductility develops. The uniquely limited width of the N-G weld enhanced the fracture toughness of the weldment in the transition temperature range and on the upper shelf when the crack tip plastic zone size exceeded the weld zone and entered the A-543 plate. This increased the resistance to fracture propagation through involvement of the tough plate metal. (Author)

Descriptors :   (*WELDS, FRACTURE(MECHANICS)), WELDING, STEEL, METAL PLATES, TEST METHODS, CRACK PROPAGATION

Subject Categories : Couplers, Fasteners, and Joints

Distribution Statement : APPROVED FOR PUBLIC RELEASE