Research Steel Surface Defect Detection Method Based On Alternating Current Field Measurement

Currently, the scope of China’s oil development has been towards the seabed resources,increasing the number of coastal offshore oil platforms. These platforms should be carried outroutinely every year to detect security risks, under normal circumstances, be detected underthe sea are steel, pipes and so on. Common detection methods can not meet the testing needs,with the emergence of alternating electromagnetic field detection technology, this technologyhas been used to detect a large area in the sea, but the detection of foreign funds expensive, isnot conducive to develop this technology, so the research post varying electromagnetic fieldtheory testing technology, to promote domestic alternating electromagnetic field technologydevelopment is necessary.This paper studies the status quo at home and abroad as well as non-destructive testingtechniques different classes alternating electromagnetic field detection technology, derivedthe basic concepts and principles of various detection techniques. On the basis of thealternating magnetic field measurement techniques on the analysis of the characteristics of analternating electromagnetic field to detect fundamental principle discussed, based on theoverall scheme proposed U-shaped coil excitation alternating electromagnetic field detectionplatform designed rectangular excitation coil probe. On this basis, software simulationanalysis using comsol excitation portion and the detecting portion, for which different testconditions were compared. Design the circuit, the magnetic core, the sensor, the signalprocessing circuit after the excitation signal generation. Software design using AltiumDesinger signal conditioning circuit, using Labview programming interface complete testpreparation software, composite second order filter circuit to achieve effectively eliminatenoise, draw different sets of data on the test results were analyzed. Alternating magnetic fieldtechnology combined with the theoretical model, through a unique detection method,combined with sensors, signal processing circuit, data acquisition software, built alternatingelectromagnetic field test platform for steel crack tested, peak voltage variation obtainedthrough multiple sets Comparative test data analysis, the characteristics of the relationshipbetween the length of the steel sheet crack depth. In this paper, the design of the platform to complete a number of experiments,theoretical analysis of the measured data and the basic line proved alternating magnetic fieldmeasurement method to measure the steel surface cracks feasibility and effectiveness.