Study of Scratch-Induced Stress Corrosion Cracking for Steam Generator Tubes and Scratch Control

Abstract

This paper introduces the field cases scratch-induced stress corrosion cracking (SISCC) of steam generator tubes in PWR and current study in laboratories. The effect of microstructure for nickel-base alloys, residual stress caused by scratching process and water chemistry on SISCC and possible mechanism of SISCC were discussed. The result shows that scratch-induced microstructure evolution contributes to SISCC significantly. The causes of scratches during steam generator tubing manufacturing and installing process were stated and scratch control is highlighted for reliability of in-service steam generator tubes.