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Alloy 825

UNS N08825

Alloy 825 material

nickel alloypipe / fitting / flangeP-No. 45

Key Engineering Metrics

Instant specifications summary for Alloy 825

Yield Strength💪
-MPa
Min specified
Tensile Strength🏋️
-MPa
Ultimate min
Carbon Eq. (CE)🧪
N/A
IIW Formula
P-No. / Group⚙️
P45
ASME Sec. IX
Flange Group🛡️
N/A
ASME B16.5
MDMT Curve❄️
Refer to
ASME B31.3

General Specifications & Standard Data

Alloy 825
Standard Specification
Alloy 825
Grade / Designation
Alloy 825
UNS Designation
N08825
ASME P-No. / Group No.
P-No. 45
ASME B31.3 MDMT Curve
Refer to ASME B31.3 Fig 323.2.2A

Minimum Design Metal Temperature rules for impact testing exemption under ASME B31.3 paragraph 323.2.2.

Mechanical Properties

Room Temp (20°C / 68°F)
Density
8140kg/m³
Min Yield
-MPa
Min Tensile
-MPa
Elastic Modulus
196GPa
Thermal Expansion
14µm/m·K
Thermal Cond.
10.8W/m·K
Poisson’s Ratio
0.34

Allowable Stress Data (ASME B31.3 Table A-1)

asme-bpvc

Allowable Stress vs Temperature

ASME B31.3 / BPVC Section II Part D Reference Curve

Max: 160.6 MPaRange: 38° - 500°
Creep Range (≥400°)10011613214816418038°150°250°350°450°500°Stress (MPa)
Temperature (°C)Allowable Stress (MPa)% of Room Temp Rating
38160.6100%
100146.991%
150140.087%
200134.484%
250128.980%
300124.177%
350120.775%
400118.674%
450117.273%
500115.872%
550
600
650

Chemical Composition (% Weight)

Heat & Product Analysis
C
≤ 0.05%
Mn
≤ 1%
Si
≤ 0.5%
S
≤ 0.03%
Cr
19.5–23.5%
Ni
38–46%
Mo
2.5–3.5%
Cu
1.5–3%
Ti
0.6–1.2%
Al
≤ 0.2%

🛡️ Service Compatibility

Severe Acid & Corrosiveexcellent

Exceptional resistance to hydrofluoric, hydrochloric, and hot sulfuric acids.

High Temp Oxidation / Carburizationexcellent

Maintains mechanical strength and oxidation resistance up to 1000°C (Inconel 600/625, Alloy 800H).

Sour Oil & Gas / Severe H2Sexcellent

Immune to SSC, HIC, and pitting in extreme sour oilfield environments.

Seawater & Brineexcellent

Zero pitting or crevice corrosion under stagnant or high-velocity seawater.

🔥 Welding & Heat Treatment

Weldabilityspecial control required
Preheat Requirements

None required. Strict cleanliness required (remove all sulfur, oil, grease, paint to avoid hot cracking). Interpass temp < 150°C.

PWHT Requirements

PWHT not required. Thermal stress relief at 870°C recommended only for Monel 400 in hydrofluoric acid service.

Charpy Impact Test (CVN)

Exempt down to sub-zero temperatures per ASME B31.3.

⚠️ Engineering Verification Notice

Material property data provided is for preliminary engineering reference. Always verify properties against the latest ASME BPVC Section II, ASTM material specification, and Material Test Report (MTR/MTC).

Alloy 825 - Material Properties — PipingCalcPro | PipingCalcPro