Alloy 2535 (UNS N08535) is a cold hardened nickel-based alloy intended for corrosion resistance in highly sour (H2S) environments with moderate chloride content, requiring high strength up to 350°F. 2535 offers increased resistance to the effects of H2S relative to stainless steels allowing its use as downhole tubular components, packers, and other subsurface equipment in sour wells with high-pressure and high-temperature (HPHT) conditions and Acid Gas Injection (AGI) wells. However, all environmental factors, including H2S, CO2 , temperature, pH, and chloride concentration, should be considered before final material selection.
UNS N08535 is classified in MR0175/ISO15156 as a type 4c alloy, with no restrictions to a partial pressure of H2S below 270°F and resistant to 200 psi H2S at 350°F.
CRA 2535E (UNS N08535) is a premium, electro-slag re-melted version of alloy 2535. The performance and consistency are enhanced through tightly controlled compositional limits and microstructural cleanliness.
24 - 27
29 - 36.5
2.5 - 4
Made by electric furnace process followed by Vacuum Oxygen Decarburization (VOD) or Argon Oxygen Decarburization (AOD)
Manufactured by traditional tube manufacturing processes, High strength tubulars should be furnished in cold worked condition
Solution Annealing Process before final cold drawing
Specified Mechanical Properties
API 5CRA / ISO 13680 Group 3 Category 25-32-3
Yield Strength ksi
Tensile Strength ksi
NACE MR0175/ISO 15156 H2S Sour Service Limits
Table A.14 Type 4c
No limit ≤ 270°F, Refer to table for temperatures up to 450°F
140 Grade not recommended for sour service
*Non-standard mechanical properties and grades are made available upon agreement.