Simulation and experimental verification of phased array ultrasonic testing process in 316L butt weld

Aiming at solving the problem of limited scanning space and low signal-to-noise ratio in ultrasonic testing of 316L stainless steel weld in China Fusion Engineering Testing Reactor (CFETR), a phased array ultrasonic testing technology based on dual matrix array(DMA) probe was proposed. Through CIVA simulation, the sound field of DMA probe under different focusing parameters was analyzed, and the testing technology of butt joint was determined. Referring to appendix I of NB/T47013.3-2015 "Nondestructive testing of pressure equipments-Part 3:ultrasound testing", the reference blocks were designed and manufactured to verify the beam coverage and signal-to-noise ratio of φ2 mm side drilled holes under the testing process. The results show that the DMA probe beamscan cover all the weld in limited scanning space, and the signal-to-noise ratio of φ2 mm side drilled holes in different locations of the reference block is greater than 15 dB. The experimental results can provide reference for the formulation of phased array ultrasonic testing technology for 316L stainless steel butt weld.