The invention provides an on-line detection
system and an on-line detection method for pipes or bars ultrasonic
phased array. The method comprises the following steps of: arranging a plurality of
concave surface phased array energy converter probes on planes which are perpendicular to the center lines of the pipes or bars and at the position which forms a certain included angle with the center lines of the pipes or bars at the peripheries of the pipes or the bars; generating an electronic control
sound field focused by the phased arrays by utilizing the
concave surface phased array energy converter probes; and switching continuously and quickly by utilizing a high-
voltage switch array, a multi-channel phased array transmit-receive
system and a
control system through a high-
voltage switch array circuit, and controlling different array elements of the
concave surface phased array
energy converter to transmit and receive at different moments, so that phased array focusing acoustic beams rotate in the pipes or bars at high speed to realize dynamic focusing and scanning. By the
system and the method, the 360-degree full-coverage scanning of the pipes or bars can be realized under the condition that the concave surface phased array energy converter probes are not moved, longitudinal and
traverse defects can be scanned and detected, and the detection speed is improved greatly while the detection accuracy is improved.