Effect of Weld Defects on the Strength of Circumferential Welds in Pipe.

Manually arc welded butt welds with and without defects of different type and size in ST52 steel pipe (102 and 133 mm od, 4 mm wall thickness) were assessed in accordance with the x-ray catalogue of the International Institute for Welding Technology and subsequently tensile tested. Tensile and yield strengths were compared with the results of x-ray defect determinations. The effect of weld defects, especially on tensile strength, was found to be surprisingly low. The reasons, and problems in applying the results in industrial applications, are discussed.