COMMON TRADE NAMES: CRA 2535E, SM2535®, 25%Cr-35%Ni, 25 CR35 Ni
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.
|≤ 0.03||24 - 27||29 - 36.5||≥ 29.5||BAL||≤ 1||≤ 0.5||2.5 - 4||≤ 1.5||≤ 0.03||≤ 0.03|
|Steel Making||Made by electric furnace process or blast furnace followed by Vacuum Oxygen Decarburization (VOD) process or Argon Oxygen Decarburization (AOD) Process|
|Pipe Making||Manufactured by traditional tube manufacturing processes, High strength tubulars should be furnished in cold worked condition|
|Heat Treatment||Solution Annealing Process before final cold drawing|
API 5CRA / ISO 13680 Group 3 Category 25-32-3
|NACE MR0175/ISO 15156
H2S Sour Service Limits
|No limit ≤ 270°F,
Refer to table for temperatures up to 450°F
|140||140||160||145||9||38||140 Grade not recommended for sour service|
|Elastic Modulus||psi x 106||28.3||27.6||26.3|
|Thermal Conductivity||W/ft h °F||5||6||6.4|
|Specific Heat||Btu/lb °F||0.09||0.09||0.09|