The Research Of Thick-walled Pipe Inspection And Evaluation Of Hydrogen Damage

Based on the pipe fragments happened in Deqilong accident, this paper research the hydrogen damage, which is usually happened in petrochemical industry. Through analysis the mechanism and damage forms of hydrogen damage, the existing hydrogen damage are re-classified. Through analysis the existing pipeline accident debris, found the root cause of pipeline damage is hydrogen damage, and further confirmed by the finite element method.Using ultrasonic, magnetic particle, penetration and other conventional non-destructive testing methods for the detection of hydrogen damage pipe fragments, compare the test results, and assess these detection methods for detection of hydrogen damage. Based on the results above, introduction of magnetic memory testing method for hydrogen damage detection. And through specific test results found that metal magnetic memory testing method is an effective detection of hydrogen damage detection. This method can detect early hydrogen damage, and can also reflect the hydrogen damage severity. However, this method also has its shortcomings, it can not determine the position of hydrogen damage in the thickness direction and the nature, but the ultrasonic testing method be able to compensate this deficiencies in that regard.Therefore, this paper introduce the combination of ultrasonic testing and Magnetic memory testing method to test hydrogen damage, and it is a effective method. The specific of this method is that, first use the magnetic memory effectively to identify defects location on the piece surface, and then conduct a review using ultrasonic testing to further determine the defects of hydrogen damage location in the thickness direction, and also the size and nature. This method can effectively discover the hydrogen pipeline damage. And at last, combinate the penetration and magnetic methods for grading the general flaw, get the hydrogen damage grading, and initially get the assessment method of hydrogen damage.