Abstract:
Aimed at bimetal turbine joint surface defects and material ultrasonic high attenuation characteristics, an ultrasonic phased array detection technique is proposed to detect the interface defects of a double metal turbine. Firstly, a finite element model of a double metal turbine is set up, based on the geometric structure characteristics of bimetal turbine, to analyze the phased array ultrasonic wave propagate in the double metal turbine and the waveform of the receiving point. Then designing and fabricating bimetal turbine specimens and curved probes with specific curvature, the positioning of the artificial defect on the sample was studied by using a bistatic ultrasonic phased array inspection process. Experimental results show that bistatic ultrasonic phased array inspection technology can achieve full coverage detection of bimetal turbine joints with high sensitivity and high positioning accuracy.