Development of a Creep Crack Detection System for the Inner and Outer Walls of High Temperature Hydrogen Furnace Tubes

The hydrogen stove pipe is a crucial component of the petrochemical industry, operating at high temperatures for extended periods. Creep cracks, particularly axial cracks in the inner and outer walls, are a common form of damage in these pipes. In this study, the ultrasonic transmission method was utilized to detect creep cracks in the inner wall, while the vertical mutual induction eddy current method was utilized to detect creep cracks in the outer wall. To accommodate actual testing conditions, the specialized fixtures of the transducers, a mechanical structure for crawling on the outer wall, a rotating sweeping mechanism and the multichannel testing mechanism were designed. Additionally, an ultrasonic eddy current control circuit and upper computer control system were developed which can successfully detecting defects in the inner and outer walls of the pipe with exceptional sensitivity and precision. These results have significant implications for improving the safety and reliability of petrochemical operations.