REPLICATE SOUR ENVIRONMENT TO EVALUATE THE STRENGTH OF METAL
WHAT CAUSES SULFIDE STRESS CRACKING?
Sulfide Stress Cracking is commonly associated with welds. Atomic hydrogen diffuses into the steel and causes embrittlement of the very narrow hard zones in the heat-affected zones adjacent to welds. Metal will crack under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulfide. SSC is one of the many environmental cracking mechanisms resulting in pipeline steels exposed to aqueous sour service environments.
How did Sulfide Stress Cracking form?
Hydrogen embrittlement can occur if the metal is subject to static or cyclic tensile stress. Hydrogen can cause changes in the mechanical properties and behavior of the metal, including:
- Reduction of ductility (elongation and reduction of area)
- Reduction of impact strength and fracture toughness
- Increased fatigue behavior
Hydrogen embrittlement can be avoided by selecting material resistant to hydrogens, such as austenitic alloys with nickel content between 10% and 30%.
PTS performs Sulfide Stress Cracking conforming to NACE TM0177, which simulates exposure of materials to standard sour conditions or other specific field conditions.
This test is normally used to evaluate material’s resistance to cracking failure under the combined action of tensile stress and a corrosive environment containing Hydrogen sulfide prevalent in the petrochemical industries. Products such as valve trims & tool joints are typically evaluated using this test for qualification of resistance to sulfide stress cracking and stress corrosion cracking.
APPLICATION OF SULFIDE STRESS CRACKING TESTING:
Helps to evaluate your materials and detect danger at an early stage
Preventing failure of sour service pipelines and ensuring their reliability and longevity
Common Test Methods
NACE TM0177
ANSI/NACE MR0175
ISO 15156
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Our expert testing team can carry out Sulfide Stress Cracking (SSC) testing of metals subject to help you to evaluate the susceptibility of materials to H2S/Sulfide stress corrosion cracking in a wet H2S environment and select suitable materials for working in H2S media.
For more information on our SSC testing, call us or send us an enquiry today.