The purpose of this investigation was to determine the effect of varying the pH of a sea water environment on the stress corrosion cracking behavior of the Ti-7Al-2Cb-1Ta alloy. Various pH levels of 1.0, 3.0, 5.0, 7.4, 9.0, 11.0, and 11.6 were studied by additions of HCl and NaOH to the as-received sea water (pH = 7.4). The titanium specimens were beta-fabricated (rolled 1900 F, 1038 C), and tested using a cantilever weight test. It was found that an increase in the pH level of the sea water from 1.0 to 7.4 decreased the stress corrosion susceptibility of the Ti-7Al-2Cb-1Ta alloy. In all cases, the mode of cracking was transgranular; yet, differences in the angle of cracking through the titanium platelet structure were observed. A distinct low ductility zone on the fracture surface of the sea water samples was noted, but no correlation could be made between the size of this zone and the pH of the solution. Photomicrographs of the specimens are included, along with macrographs of the fractured surfaces.

Subject
Marine environments, Water, Ions, Notches, Fracture surfaces, Corrosion testing, Transgranular stress corrosion cracking, Acidity, Stress, Titanium, Fracture, Titanium alloys, Stress corrosion cracking
© 1970 National Association of Corrosion Engineers
1970
You do not currently have access to this content.