Ultrasonic inspection method for super pipeline nozzle of main steam system

The invention relates to an ultrasonic inspection method for a super pipeline nozzle of a main steam system. The ultrasonic inspection method comprises the steps of scanning by use of a straight beam method and scanning by use of an angle beam method; regions to be scanned include the nozzle and a transitional area of the nozzle; according to the straight beam method, peripheral and axial fine scanning is performed on the external surface and the internal surface of the nozzle, and the saddle-shaped external surface part of the transitional area by use of a straight beam probe; according to the angle beam method, peripheral and axial fine scanning is performed on the external surface and the internal surface of the nozzle, and the saddle-shaped external surface part of the transitional area by use of two angle beam probes with different refraction angles. The ultrasonic inspection method is capable of effectively inspecting internal defects of the nozzle.