Study on Corrosion Fatigue Damage Behavior of Marine High-strength Steel in Seawater Environment

Corrosion fatigue damage affects the safe service of marine equipment seriously. In order to study the crack propagation law and corrosion fatigue damage mechanism of marine equipment in seawater environment,fatigue crack growth tests in air and seawater environment for marine high-strength steel 10CrNi3MoV were carried out. And the influence of sea water environment on fatigue crack growth rate by comparing different crack growth rates(CGR)and fatigue life in air and seawater environment were analyzed,and the corrosion fatigue behavior history of marine high-strength steel was obtained. Based on the observation of corrosion fatigue fracture morphology and the analysis of corrosion products, the corrosion fatigue damage mechanism of typical marine high-strength steel was revealed. The research results showed that corrosion fatigue damage starts from the pitting corrosion pits on the metal caused by the uneven electrochemical reaction on the surface of the substrate,and gradually evolves into microcracks under the combined action of corrosion and fatigue. Seawater environment has a significant impact on the CGR and fatigue life,significantly accelerating crack propagation and reducing fatigue life. With the increase of the CGR,the influence of mechanical fatigue damage on the crack growth is dominant compared with seawater corrosion. What’s more,anodic dissolution with cleavage characteristics is the main mechanism in the corrosion fatigue damage evolution process of marine high-strength steel. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.