Electromagnetic ultrasonic energy converter for automatic detection of surface of steel rod

The invention provides an electromagnetic ultrasonic energy converter for automatic detection of a surface of a steel rod and belongs to the technical field of steel rod surface inspection. The electromagnetic ultrasonic energy converter comprises a detection coil, a magnetizing device and a work piece to be detected. The magnetizing device is formed by two sets of completely same coils and shells. The coils are formed by winding varnished wires and two sets of the coils are connected in series; and when the coils are electrified by direct current, namely a stable and constant magnetic field B is axially distributed in a rod material to be detected. The shell of the magnetizing device is made of a ferromagnetic material so that a magnetic field generated by the coils is limited in a magnetic circuit formed by the shell of the magnetizing device and the rod material to be detected; and therefore, the magnetization of the rod material can be realized to the greatest extent. The electromagnetic ultrasonic energy converter is mounted on a production line of the steel rod to carry out online detection on the quality of the rod material, find out the defects on the surface of the rod material in time and ensure the quality of a rod material product.