Observations on Sustained Load Environmental Crack Growth of a Titanium 8Al-lM0-lV Alloy

Sustained load environmental cracking of a mill annealed titanium 8Al-1Mo-1V alloy was investigated by methods amenable to fracture mechanics. Two environments were considered: 3.5% NaCl solution and distilled water, both at room temperature. Varying amounts of crack propagation followed by subsequent crack arrest were detected at K levels considerably below an apparent K_Iscc (almost 2 to 1) that would be determined from a time to failure test technique. At crack arrest locations along the specimen surface, minute amounts of crack division were often observed under magnification.