Ultrasonic detection method for butt weld of composite steel plate and flat plate for water bridge

The invention relates to the technical field of ultrasonic flaw detection, and discloses an ultrasonic detection method of a flat plate butt weld of a composite steel plate for a water bridge, which comprises the following steps: selecting a waveform, and selecting longitudinal wave flaw detection; determining a probe angle; frequency is selected, and the flaw detection frequency is 0.5-2.5 MHZ; a calibration test block and a reference test block are manufactured, the structures of the calibration test block and the reference test block are the same as those of the stainless steel and carbon steel composite steel plate to be detected, the calibration test block is a CSK-IA test block of a composite stainless steel layer, and the reference test block is in a strip-shaped plate shape; the calibration test block is used for calibrating a baseline, a probe front edge and a probe K value during scanning; making a distance amplitude curve, and making the distance amplitude curve on the reference block; ultrasonic s