FRACTURE TOUGHNESS OF X7006-T6351ALUMINUM ALLOY PLATE WELDMENTS FOR THE LARGE (ADVANCED) STRUCTURES INDEPENDENT DEVELOPMENT PROJECT (TASK B) MATERIALS AND MANUFACTURING DEVELOPMENT.

摘要

The report is concerned with the 'precracked-Charpy'fracture toughness evaluation of 3/4in. X7006-T6351plate and its weldments. Fracture toughness, (W/A) sub c,data at room temperature and LN sub 2temperature are presented for (1) four principal notch orientations in the base-metal and (2) two weld fusion zone directions to assess resistance to longitudinal and transverse weld cracking. The variation of fracture toughness of subthicknesses of the basic plate thickness in both the base metal and weld fusion zone is determined by using varying width 'through-thickness'notched specimens. 'Throughthickness'notch data are used to calculate critical-crack size for two base-metal and two weld-fusion zone orientations. Critical-flaw sizes are calculated for both roomtemperature and LN sub 2temperature. The fracture toughness of the X7006alloy is compared with that of the X7039alloy reported in an earlier report. (Author)