High-cycle fatigue performance of corroded Q690E high strength steel and Q690qENH high-strength weathering steel: Fid-Bau Portal

High-cycle fatigue performance of corroded Q690E high strength steel and Q690qENH high-strength weathering steel

Yue, Yanan / Gao, Shuling / Li, Ning / Zhang, Rui

Abstract High-strength steel and high-strength weathering steel have been increasingly used in engineering constructions. Corrosion leads to a decrease in the fatigue strength of steel, posing a threat to the safety and reliability of the engineering project. The fatigue strength reduction caused by corrosion usually depends on the type of steel and the corrosion time. In this study, indoor acetic salt spray accelerated corrosion test (ASS) and high-cycle fatigue test were carried out on Q690E high-strength steel and Q690qENH high-strength weathering steel, obtaining the time-varying laws of corrosion damage, the composition of corrosion products, and the fatigue life under different corrosion times. The results show that in the corrosion test process, the uniform corrosion depth $C$ and the pitting depth $S_{z}$ of both types of steel conform to a power function model. In contrast, other pitting parameters conform to a linear model. On the surface of the Q690qENH high-strength weathering steel specimen, $α$ -FeOOH was generated first, which hinders the progress of corrosion. During the fatigue test, under the same stress range, the fatigue life decreases with the increase in corrosion time. For the corroded specimens, the corrosion parameters ( $C, S_{z}$ ) were negatively correlated with the fatigue life linearly. This study can provide a reference for the design and use of high-strength and high-strength weathering steel.

Highlights • Corrosion properties of Q690E and Q690qENH were studied. • Q690qENH has higher corrosion resistance than Q690E. • Corrosion-fatigue life gradually decreases as the corrosion time increases for Q690E and Q690qENH. • There is a linear negative correlation between the corrosion damage and the uniform corrosion and pitting corrosion. • The correlation between uniform corrosion and corrosion-fatigue life is higher than that of pitting corrosion.