Lifetime Estimation of Chain Plates for Floodgates Working in Seawater by Continuum Fatigue-Creep Damage Theory and Transient Analysis of Diffusion Process of Hydrogen

Lifetime estimation of chain plates made of 45Cr high strength steel for floodgates working in seawater has been performed by considering fatigue-creep crack initiation and hydrogen assisted crack propagation at the plate. According to the records of operating history of the floodgates, average lifetime of the chain plate is in range of 18~22 years. Estimated lifetime of the chain plate by continuum fatigue-creep damage theory and transient analysis of the diffusion process of atomic hydrogen in the metallic lattice is in range of 19~25 years.