Effect of Derofmation and Orientation on SCC of Alloy 690

Alloy 690 and its weld metals (Alloys 152 and 52) are now widely used as preferred materials compared to Alloy 600 and its weld weld metals (Alloy 182 and 82).  Alloys 690, 152 and 52 were tested in pressurized water reactor primary water at 290 to 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 most cases were in the range of 1 to 10 x 10^–9 mm/s, but growth rates in the range of 0.4 to 4 x 10^–7 mm/s were observed in 1-dimension cold rolled Alloy 690 tested in the S-L orientation.