Causes of Flaw Detection Errors of Q345B Seamless Steel Tubes

(1) The high weld seam reinforcement of Q345B seamless steel pipe makes the primary wave flaw detection impossible, and only the triple wave flaw detection can be used. The characteristics of the sound field of the third wave are more complex, which brings some difficulties to the waveform analysis. The sound beam spreads after two reflections, and the sensitivity is low.

(2) The radius of curvature of the small-diameter Q345B seamless steel pipe is small, and the reflected wave sound beam generated by the incident sound beam from the outer wall of the pipe to the inner wall will diverge due to the curvature, resulting in loss of sound energy. In addition, the arc surface of the outer wall of the Q345B seamless steel pipe directly affects the coupling between the planar probe and the outer wall of the Q345B seamless steel pipe.

(3) The internal and external surface state of Q345B seamless steel pipe affects the size of surface compensation and the result of interpolation estimation.

(4) The type of Q345B seamless steel pipe probe, the size of the incident angle, the size of the chip, the frequency and the shape of the contact surface and other factors affect the accuracy of the equivalent method.

(5) The fitting error of groove depth-amplitude curve type affects the accuracy of interpolation estimation of Q345B seamless steel pipe.

The error is not a mistake, but there is a standard. Otherwise, the Q345B seamless steel pipe produced will affect the quality. For the Q345B seamless steel pipe, it is also necessary to carry out research on strengthening technology and quality to promote the continuous improvement of the efficiency of the Q345B seamless steel pipe.