Study On Ultrasonic Testing Technology Of Cast Iron

According to the standards of the Iron and Steel Association,oil pipe in the production,processing and put into use before the full length of the thickness of the measurement.At present,the conventional ultrasonic thickness gauge is a point by point measurement method,the lack of continuous measurement of the entire pipe capacity.The cast pipe is Coarse-grained materials,the grain distribution has anisotropy,the reflected signal of the ultrasonic wave in the propagation is submerged by the noise formed by the scattering effect of the crystal interface,and can not receive the accurate echo signal;Followed by the presence of slag and porosity in the cast iron,which makes it difficult to propagate and reflect the ultrasonic waves in the tissues.The different cast pipe materials have different The rate of spheroidization.This will cause the ultrasonic wave The change in sound velocity affects the measured value.In addition,the surface of the cast iron pipe is rough,the coupling condition of the ultrasonic emission is poor,and the small signal received is only some distortion clutter.In this paper,the ultrasonic pulse continuous thickness measurement system can continuously measure the thickness of cast pipe pipe,the system can achieve the full thickness of cast pipe pipe thickness measurement.In this paper,the design and processing of the ultrasonic flooding focusing probe are completed.Four different coupling devices are designed according to the characteristics of the probe.The four coupling devices are designed by Fluent to provide the basis for the experiment.Then,the ultrasonic testing system Accuracy and accuracy of test results.In this paper,the internal flow field of the four coupling devices is simulated and analyzed.After the fluid enters the internal flow field of the coupling device,the turbulence in the lower part of the coupling device is gradually reduced with the improvement of the device,The air bubbles can be discharged in the coupling device.Finally,the coupling effect is better of the coupling device.In this paper,the development of ordinary straight probe emission frequency of(3MHz,4MHz),piezoelectric wafer materials using lead zirconate titanate piezoelectric ceramic(PZT-5X),wafer diameter of 12 mm,damping block material for the epoxy resin plus tungsten powder,Protective film made of copper,shell selection of copper.Focusing probe through the acoustic lens to make ultrasonic convergence,acoustic lensmaterial selection of plexiglass,the straight probe protective film made curved surface,the curvature of the same with the outer surface of the pipe.The probe matching circuit is then analyzed to determine that the matching inductance is(4.3?10-15H).The ultrasonic acoustic field of circular transducers with frequency of(2.5MHz,3MHz,3.5MHz and 4MHz)is simulated and analyzed respectively.It is concluded that the directional direction of the beam is improved with the increase of the ultrasonic emission frequency of the probe.Area length increases.