Laboratory Program to Examine Effects of Layup Conditions on Pitting of Alloy 600. Final Report (PWR)

摘要

The effect of various layup conditions on pitting of Alloy 600 tubing for steam generators was studied in beaker tests at 40 exp 0 C (104 exp 0 F). In addition, several methods to inhibit pitting were studied. The pitting solutions studied were copper chloride or seawater plus simulated sludge containing copper, copper oxide and magnetite. Results show that the pitting of Alloy 600 initiated in less than three weeks in the copper chloride solution with about 700 ppM chloride present. The same results were obtained in the seawater solution with about 6000 ppM chloride present. Retardation of pitting was achieved in three different ways: (1) decreasing the oxygen content of the solution, (2) decreasing the copper content of the solution, and (3) increasing the pH of the solution. (ERA citation 08:035799)