Stress Relaxation Cracking is a creep cracking mechanism that operates in the low creep temperature regime in various alloy systems. Cracks occur with very little ductility, typically within the first year of operation but they can also occur during PWHT, or even later in operation life. This presentation will focus on stainless steels and nickel base alloys but the generic ideas can apply to low alloy steels as well. Taking a stress and ductility approach, it will discuss why cracking occurs in some welds and not in others, why some alloys are more prone to cracking than others, why there is an influence of grain size, and other contributing factors. General mitigative actions will be given and it will be explained why they work.
Date Recorded: November 13, 2024
Instructor: Jan-Willem Rensman, Fluor