Search
Filters
Close

New Insights On Groove Criticality Formed Onto Carbon Steel After Sulfide Stress Cracking Test

The sulfide stress cracking (SSC) resistance of carbon steels and other alloys is commonly addressed through testing according to NACE TM01771 or NACE TM03162. The Method A of the first standard is focused on tests using uniaxial tensile (UT) while the second standard considers 4-point bend (4PB) type of loads. A common way of qualifying a material according to these standards is the absence of failure of the specimens or SSC crack initiation at the surface of the material after a test duration of 720 hours (1 month). After testing, cross-sectional observations of non-broken specimens often reveal so-called “grooves” that can be significantly different in shape and depth depending on the test method, steel grade or environment considered.  

Product Number: 51322-17871-SG
Author: Christophe Mendibide, Flavien Vucko
Publication Date: 2022
Industry: Coatings
$0.00
$20.00
$20.00

This work was conducted to address the experimental parameters influencing the formation of so-called superficial microgrooves during sulfide stress cracking (SSC) test that render sometimes difficult the decision on material qualification. It gives complementary results to a work published earlier. 

Our investigations underline that, in our test conditions and for 2 different steel grades, grooving is not sulfide stress cracking initiation. Grooves can however act as stress concentrators and promote cracking. Calculation using finite element modelling allows to demonstrate that these initiations occur only if some plastic deformation is generated. 

The discussion suggests that grooving and cracking are competing processes but that grooving should prevent seeing cracking if the tested material is susceptible.  

This work was conducted to address the experimental parameters influencing the formation of so-called superficial microgrooves during sulfide stress cracking (SSC) test that render sometimes difficult the decision on material qualification. It gives complementary results to a work published earlier. 

Our investigations underline that, in our test conditions and for 2 different steel grades, grooving is not sulfide stress cracking initiation. Grooves can however act as stress concentrators and promote cracking. Calculation using finite element modelling allows to demonstrate that these initiations occur only if some plastic deformation is generated. 

The discussion suggests that grooving and cracking are competing processes but that grooving should prevent seeing cracking if the tested material is susceptible.  

Also Purchased