DETECTION AND CHARACTERIZATION OF DEFECTS IN WELD JOINT BY USING ULTRASONIC NON-DESTRUCTIVE TESTING TECHNIQUE

Abstract

In industrial production, the annual production of welded structure is about 45% of steel’s, due to the inherent defects in welding technology and the characteristics of metal, there are always certain flaws in welding structure. In addition, welded structure is often used in more important equipment and structure. Therefore, nondestructive testing of welded structures is very necessary and important. The purpose of the non-destructive testing is to detect, locate and size the defect or discontinuities in materials. There are many types of non-destructive testing technique (radiography, ultrasonic, dye penetrant, eddy currents, magnetic particles, etc.), and each type offers advantages and disadvantages, depending on the material being inspected, type of discontinuity, medium in which the material is, etc. Thus, the choice of the most appropriate method depends on the desired application. In the detection of welding defects, it is universally acknowledged that ultrasonic test...