RETARDATION OF FATIGUE CRACK GROWTH BY CORROSION ACCELERATOR INJECTION

Abstract

In this study, fatigue crack growth was retarded by injecting corrosion accelerator, Nitric acid (HNO₃), into the crack to induce corrosion. The presence of the corrosion products is expected to reduce the crack opening width and act as a wedge to control the crack closure. Fatigue tests were carried out on the compact tension (CT) specimens. The test revealed that the corrosion process due to HNO₃ injection ends after 24 hours. Then, the reduction in crack opening displacement range can be observed. Retardation in the crack growth was observed regardless of the load range and the effective stress intensity factor range (ΔK_eff) at injection. Meanwhile, the retardation level tends to be affected by the ΔK_eff and crack length at injection.