Alloy 690, of various microstructures and types of cold work, was tested in representative pressurized
water reactor primary water at 340 and 360 °C. Intergranular cracking was observed on Alloy 690 at
constant stress intensity factor (no cycling) and with “gentle” cyclic loading. Crack growth rates in some
cases were in the range of 1 to 10 x 10–9 mm/s, but growth rates as high as 7 x 10–7 mm/s were
observed in Alloy 690 with microstructural banding and 1-dimension cold rolling that was tested in the
S-L orientation.
Keywords: Stress corrosion cracking, Alloy 690, cold work, microstructural inhomogeneity, banding,
PWR, PWSCC, high temperature water