The corrosion fatigue behavior of magnesium alloy influenced by corrosion inhibitors with the differentiated inhibition mechanisms

• The influences of three corrosion inhibitors with different action mechanisms on the corrosion fatigue behavior of Mg alloys were studied. • The relationship between the static corrosion and fatigue corrosion behaviors of Mg alloys with corrosion inhibitors was clarified. • A multi-dimensional screening and evaluation framework for corrosion inhibitors of Mg alloys was proposed. The effects of three corrosion inhibitors on Mg-Zn-Y-Nd alloy corrosion fatigue were investigated. Salicylic acid (SA) induces uniform but rapid corrosion, limiting fatigue life improvement. 2, 6-pyridinedicarboxylic acid (2,6-PDCA) delays crack initiation under low stress yet fails to fully suppress localized corrosion. Paeonol condensed cysteine Schiff base (PCCys) significantly inhibits both uniform corrosion and localized attacks, enhancing corrosion fatigue life. Localized corrosion behavior, rather than isolated corrosion rate metrics, critically determines mechanical performance under combined corrosive-dynamic stress conditions. A multi-parameter evaluation framework integrating localized corrosion, corrosion rate, and stress effects is proposed for practical screening of corrosion inhibitors for magnesium alloys.