Nondestructive Testing of Radial Friction Welds

TWI Industrial Member Report Summary 281/1985

By J L Turner and M Endo

Background

This report contains the results of nondestructive testing trials on 96mm diameter, 10mm wall thickness X52 steel pipe sections joined by the radial friction welding technique. A total of 21 specimens (made under five different welding conditions, four being deliberately chosen to produce defective welds) were extensively examined using manual ultrasonic methods, followed by radiography and dye penetrant testing on selected specimens. The selected welds were then subjected to sectioning and bend testing. Correlations between destructive and nondestructive tests revealed that all the defects that led to the failure of 13 (out of a total of 30) bend test specimens had been initially detected by ultrasonics, except for two, both of which were identified with metallurgically weak zones of ferrite (containing microscopic inclusions) at the root of the weld. Attempts were made to size the larger inclusions in the weld roots using ultrasonic amplitude measurements referred to a set of spark-eroded notches in a suitable calibration block. With the ultrasonic sensitivity settings used here, root defects of height 0.2mm or more could be detected and sized.