Research On Ultrasonic Automated C-scan Test Of Copper-Steel Weld And Technology Of Denoise

In this paper, the ultrasonic automated C-scan test system was improved and optimized by using the advanced control technology, computer program development techniques, ultrasonic signal processing and ultrasonic C-scan test techniques, meanwhile, the autoumatization, digital and graphic of the inspection of the defect in the copper steel weld were realized.The effect of the vibration and noise generated by the running motor was brought down by resetting the operating parameters of the automatic control system; the security of the system operation was ensured and the automated performance of the motor-control module was increased by fixing two safety control switcheson on the travel guide which was connected with the 2# motor.The interface of the detection software was optimized and the function was further developed:dynamic tracking of the location of the beginning wave was achieved by adding a "waveform position" button so that the structure of the probe holding device was simplified by replacing the probe adaptive device with the button. The running speed of the detection software was improved through opening multi-threaded approach in the program, and the detection speed was enhanced."Ultrasonic C-scan" buttons was added in the test program to achieve the real-time display of ultrasonic A-scan and ultrasonic C-scan. C-scan display mode change button was added to achieve the conversion between two ways of C-scan image display. The way of the result save was changed into a new way by which the result save could be automatically saved as a test report in Microsoft Word format, facilitating the edit and print of the test results completed by test worker.For electrical noise interference, some measures to reduce the noise were adopted on the related devices of the equipment, and wavelet transform was tried to denoise, but the analysis of the denoising method of wavelet denoising didn't apply to elimination of transient electrical noise interference. Given the speciality of transient electrical noise interference, a new method of ultrasonic signal processing called "Asynchronous Signal Difference Values Comparetion" was proposed, and the purpose of eliminate the transient electrical noise interference was ultimately achieved.Based on the Completion of detection technology evaluation test using contrast sample, ultrasonic automatic C-scan inspection test of the 20 samples of natural copper steel weld were completed. The morphological characteristics of C-scan images of different defects including slag, incomplete fusion, Shrinkage void and shrinkage porosity were analysed combining A-scan waveform characteristics of these typical defects. By using the destructive test, not only the reliability of these ultrasonic C-scan images of the typical flaws was proved, but also the capability of the ultrasonic automatic C-scan inspection system was validated well, and the test results were stable and reliable.