In situ observation of short fatigue crack propagation in oxygenated water at elevated temperature and pressure

A new method is demonstrated for in situ measurement of short crack propagation rates during a corrosion fatigue test of an austenitic stainless steel within a windowed autoclave at 250 °C, 50 atmospheres, oxygenated water. Digital image correlation is used to monitor crack growth through measurement of the opening displacements of defects; either focused ion beam (FIB) milled notches from which fatigue cracks initiated, or stress corrosion cracks that subsequently propagated by fatigue.

► We demonstrate a new method for in situ measurement of short fatigue crack propagation rates.
► Short corrosion fatigue cracks are observed in a windowed autoclave.
► Digital image correlation is used to measure crack opening displacements.
► Crack growth rates are measured at 250 °C, 50 atmospheres, oxygenated water.