25 Chrome

Also Known As

• 25 Chrome Duplex
• 25Cr
• SM25CR®
• VM® 25
• 2507
• Duplex 2507

Suitable Applications

Corrosive environments containing the presence of CO2 , low H2S, and chlorides

High-pressure, high-temperature (HPHT), sweet (CO2) environments where localized corrosion is a concern (high temperature, high chlorides, and low pH)

Product Availability

FORMS:
Seamless Pipe, Tubing

OD:
MIN OD: 2-7/8”
MAX OD: 10-3/4”
Standard & Non-Standard Sizes Available

RANGE:
R1, R2, R3

25 Chrome

UNS S31260 | Datasheet

25 Chrome Applicable Environments25 Chrome (UNS S31260), also referred to as 2507 Duplex or Duplex 25 Chrome, is a cold hardened duplex stainless steel intended for corrosion resistance in sweet (CO2) and mildly sour (H2S) environments with high chloride content, requiring high strength up to 450°F.

25 Chrome offers increased resistance to the effects of CO2 , chlorides, pH, and temperatures relative to 22 Chrome allowing use as downhole tubular components, packers, and other subsurface equipment in deeper wells with high-pressure and high-temperature (HPHT) conditions where pitting corrosion from high chlorides are a concern.

This alloy is classified in MR0175/ISO15156 as a duplex stainless steel having a Pitting Resistance Equivalent Number ≤40, suitable for H2S partial pressure ≤0.3 psi.

Chemical Composition

CCrNiFeMnSiMoCuPSWN
≤ 0.0324 - 265.5 - 7.5BAL≤ 1≤ 0.752.5 - 3.50.2 - 0.8≤ 0.03≤ 0.030.1 - 0.50.1 - 0.3
(mass %)

Manufacturing Process

PROCESSDESCRIPTION
Steel MakingMade by electric furnace process or blast furnace followed by Vacuum Oxygen Decarburization (VOD) process or Argon Oxygen Decarburization (AOD) Process
Pipe MakingManufactured by traditional tube manufacturing processes, High strength tubulars should be furnished in cold worked condition
Heat TreatmentSolution Annealing Process before final cold drawing

Specified Mechanical Properties

API 5CRA / ISO 13680 Group 2 Category 25-7-3 
GradeYield
Strength
ksi
Tensile
Strength
ksi
Elongation
%
Hardness
HRC
NACE MR0175/ISO 15156
H2S Sour Service Limits
minmaxminminmax
656590902526Table A.24
(annealed)
H2S ≤ 3.0 psi,
Temp ≤ 450°F
7575100902526
1101101401251136Table A.25
(cold-worked)
H2S ≤ 3.0 psi
1251251501301036
140140160145938140 Grade not recommended for sour service
*Non-standard mechanical properties and grades are made available upon agreement.

Typical Physical Properties

  70°F200°F400°F
Densitylbs/in30.28
Thermal ExpansionX10-6/°F77.58
Elastic Moduluspsi x 1062928.227
Poisson Ratio0.240.240.24
Thermal ConductivityBtu/ft h °F8910
Specific HeatBtu/lb °F0.120.120.12

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