Influence of Refractive Angle Change on Ultrasonic Testing Results of Welding Defects Studied by Analysis of Variance

Ultrasonic testing was carried out to three specimens respectively containing three kinds of welding defects including slag inclusion on the blowhole, crack and incomplete penetration with different refraction angles, and then the influence of the refraction angle change on the ultrasonic testing results of these three welding defects was studied by the analysis of variance (ANOVA) technique. The results show the change of the refraction angle had no significant influence on the location and length testing results of these three welding defects. It also had no significant influence on the testing results of the highest reflected amplitude of body defects such as slag inclusion on the blowhole. However, it had significant influence on the testing results of the highest reflected amplitude of plane defects such as crack and incomplete penetration.