Performance of High Strength UNS N08830 in Hydrogen Stress Crack Testing to Simulate Conditions Arising from Subsea Cathodic Protection

The subject of hydrogen stress cracking of various high strength Nickel alloys has recently been reported by others. Comparisons of results for different test methods including Slow Strain Rate Testing (SSRT) and Incremental Step Loading (ISL) were performed.A new Ni-Cr-Mo-Fe alloy known as ATI 830™ alloy (N08830) was recently tested to determine its resistance to Hydrogen Induced Stress Cracking (HISC) simulating conditions arising during cathodic protection in a subsea environment.The unique set of test methods and conditions included SSRT and ISL all using precharged specimens with ongoing continuous charging during testing. Test specimens utilized different geometries including smoothed and notched along with round and rectangular cross sections.The paper draws key conclusions based on comparisons of test methods and also compares N08830 alloy results to other high strength CRA’s used in Oil and Gas subsea production equipment.

Product Number: 51319-12989-SG
Author: Njall Stefansson
Publication Date: 2019