Experimental study on the corrosion testing of a buried metal pipeline by transient electromagnetic method

Purpose This paper aims to clarify the transient electromagnetic method used for the nondestructive testing of the corrosion of an in-service buried metal pipeline in trenchless state. Design/methodology/approach The paper designed corrosion models indoor and infield for testing. A method for calculating the residual wall thickness of metal pipelines was also proposed. The calculation method was verified by the test results. In the test, the receiving probe was improved by the addition of a Mn-Zn ferrite core. The amplitudes of the test results obviously increased, and the calculation accuracy was improved. Findings The paper states that the transient electromagnetic method can detect the uniform corrosion distribution of a certain section of a pipeline. A multi-channel profile of the induced electromotive force and the calculated values of the residual wall thickness can be used to confirm the position and degree of corrosion defects, respectively. Research limitations/implications The transient electromagnetic method is more effective for large-area corrosion than for localized corrosion (pitting). Practical implications The paper includes implications for the development of nondestructive testing method of the corrosion of an in-service buried metal pipeline. Originality/value This paper proved the feasibility and reliability of using transient electromagnetic method to test the corrosion of a buried metal pipeline based on experimental study.