Hydrogen induced stress cracking (HISC) and DNV-RP-F112

Abstract

Duplex stainless steels are widely used in subsea petroleum production installation. In many instances such steels are a robust solution to the design and manufacturing challenges. However, a number of failures have occurred, which were attributed to Hydrogen Induced Stress Cracking (HISC). Several failure investigations and extensive testing have been carried out over the last 5-10 years, and a design guideline has been established; DNV-RP-FI12. The article presents HISC as a failure mode, with a brief summary of the necessary conditions and failure characteristics.The testing and research effort into HISC is described. Finally DNV-RP-FI 12 "Design of Duplex Stainless Steel Subsea Equipment Exposed to Cathodic Protection" is introduced and the main features are outlined.