EFFECTS OF DISSOLVED-OXYGEN AND HYDROGEN-PEROXIDE ON THE CORROSION POTENTIAL OF 316L STAINLESS-STEEL IN HOT LITHIUM HYDROXIDE SOLUTION

In the present work, the effects of dissolved oxygen and hydrogen pero xide on corrosion potential have been studied on type 316L stainless s teel in a hot lithium hydroxide solution. The results indicate that th e corrosion potential will remain at around - 850 mV vs SCE if the dis solved oxygen in the solution is controlled at a level of less than 10 ppb. However, 316L stainless steel will become completely passivated when about 650 ppb of oxygen exists in the solution. As a result, the corrosion potential of 316L steel will rise to around - 400 mV vs SCE, and eventually, with longer immersion times, to even higher values, e .g. - 300 mV vs SCE. However, the presence of less than 500 ppb H2O2 h as no significant effect on the corrosion potential. A potential jump (from - 850 to - 500 mV vs SCE) is observed only when a large amount o f H2O2, for instance 1 ppm, is present in the solution. Related to rad iolysis of water and with potential-dependent stress corrosion crackin g, the effects of dissolved oxygen and hydrogen peroxide on the corros ion potential of 316L stainless steel in the hot lithium hydroxide sol ution have been discussed.