Investigation on Corrosion Fatigue Properties of TA15 Alloy in 3.5%NaCl Salt Spray

Abstract:

In this paper, the corrosion fatigue properties of TA15 alloy in 3.5%NaCl salt spray were investigated at different stress ratio(R= –1, 0.06 and 0.5). An equation describing the Sa-Sm-N curved surface of the alloy was established on the basis of the experimental results, that is, N=1.83×1013/[888Sa /(888–Sm)–329.51]3.65. The result according to the cyclic displacement response of the fatigued alloy show that the cyclic hardening/softening characteristic of TA15 alloy in the salt is was dependent on the applied stress ratio R. SEM observations of the fracture surface indicate that the corrosion fatigue fracture of TA15 alloy presents multi-fatigue crack initiations characterized mainly by the cleavage morphology. In the crack growth zone, the fracture morphology shows that the change of deformation resistance is relative to the stress ratio.

Key words:TA15 alloy; 3.5%NaCl salt spray; corrosion fatigue; average stress; SEM