Nondestructive Testing of Corrosion-Resistant Alloys and Dissimilar Weld Materials

摘要

In the oil and gas and power generation industries, carbon steel (CS) pipe is frequently clad with a corrosion-resistant alloy (CRA) to create components with specific properties, such as high-temperature resistance in one area and good corrosion resistance in another. These same CRAs can also be used as filler material for girth welds (Figure 1). These metal interfaces, as well as many other types of dissimilar metal welds, can present challenges during nondestructive testing because of the changes in density and acoustic properties of the materials. Radiography is often used to inspect dissimilar metal welds and interfaces; however, radiography is associated with long exposure times and potentially harmful radiation. Because of these difficulties, along with developments in the field of phased array (PA) technology, ultrasonic PA inspection may be a good alternative for these types of inspections.