Industrial radiography (RT) is a time-tested technique for examining a welded joint and the heat-affected zone after manufacturing. But RT has obvious limitations: it’s insensitive to mis-oriented planar defects, it does not provide immediate feedback to the welders, and it’s disruptive to other work at the job site. Radiography presents important safety concerns as well.
Codes, standards, and technology have evolved to allow the use of phased array ultrasonic testing (PA UT) in lieu of RT for the inspection of austenitic welds. First adopted on a wide scale at nuclear power plants nearly 15 years ago, the use of dual (2D) matrix array probe assemblies has expanded to oil and gas and other industries where fast, reliable, safer inspections of highly attenuating austenitic welds are necessary.