Quantitative analysis of wall thinning of bimetallic clad steel tube based on pulsed eddy current

Bimetallic clad steel tube (BCST) has been widely adopted in onshore and offshore oil and gas transportation due to its excellent corrosion resistance and mechanical properties. Aged BCSTs are susceptible to the initiation of various types of defects, including corrosion, dents, cracking/leakage, and wall‐thinning defects. However, due to the complex structure of BCST and the different materials of inner and outer tubes, it is difficult to implement conventional nondestructive testing. In light of this, a finite element simulation model is established based on the pulsed eddy current testing technology in this paper. Through a series of simulation analyses, the influence of tubing material, defect location, and other factors on the detection results is intensively investigated. By establishing the mapping relationship between the detection signal characteristics and the wall thickness reduction ratio, it is confirmed that there is a quadratic relationship between the differential voltage peak value and the wall thickness reduction, and the defect identification and quantitative evaluation are carried out. The validity of the proposed defect identification and quantitative evaluation method is verified by experiments, which provides a theoretical basis for BCST nondestructive testing and state maintenance. This work facilitates BCSTs structural integrity management and state maintenance decisions, which are critical to the safe operation of the oil and gas system.