Incoloy 825 Seamless Pipes

Overview of Incoloy 825 Seamless Pipes

Incoloy 825 Seamless Pipes (UNS N08825, Werkstoff Nr. 2.4858) are pipes made of nickel-iron-chromium alloys, without the longitudinal weld seam. The smooth construction provides uniform metallurgical properties throughout the entire body of the pipes, which provides the structural integrity needed in high-pressure, high-temperature and corrosion-critical service environments.

UNS N08825 is an alloy designation stipulated under ASTM B423 / ASME SB423 standards of seamless nickel-iron-chromium-molybdenum-copper alloy pipe and tube. The pipes ASTM B423 UNS N08825 and SB 423 UNS N08825 are commonly used in industries, where the resistance to aggressive media is obligatory.

The regulated addition of molybdenum and copper offers excellent service in the oxidising acid like nitric acid and reducing acid like sulfuric and phosphoric acid. The stabilization of titanium eliminates grain-boundary sensitization, which greatly increases the ability to resist intergranular corrosion.

Incoloy 825 seamless pipe products are also drawn using a single solid billet as opposed to weld fusion, which eliminates heat-affected regions, variation in wall thickness at seam, and risk of failure of seams in cyclic pressure. ASTM B423 UNS N08825 seamless pipes are supplied in the solution-annealed and rapidly cooled state, which results in an optimum microstructure in these pipes and maximum corrosion resistance.

Why Seamless?

Having no weld line removes the most vulnerable area of a pipe. Incoloy 825 seamless pipes are used where the pressure integrity and the corrosion resistance cannot be compromised for critical services, including nuclear fuel reprocessing, sour gas (NACE MR0175) and deep-sea offshore extraction.

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Table of Content

Key Features & Advantages of Alloy 825 Seamless Pipe
Manufacturing Process of Inconel 825 Seamless Pipes
Specifications of Incoloy 825 Seamless Pipes
Incoloy 825 Seamless Pipe Equivalent Grades
Chemical Composition of ASTM B423 UNS N08825
Mechanical & Physical Properties of B423 UNS N08825 Pipes
Applicable Standards
Pressure Ratings of ASTM B423 Incoloy 825 Seamless Pipes
Schedule & Wall Thickness Chart
Applications of Incoloy 825 Seamless Pipes

Key Features & Advantages of Alloy 825 Seamless Pipe

Exceptional Corrosion Resistance: Resistant to sulfuric, phosphoric, and nitric acids, chloride-induced pitting, crevice corrosion, and stress corrosion cracking in both oxidizing and reducing environments.
No Weld Seam: Manufactured from a single solid billet. No heat-affected zones, no seam inconsistencies — delivering uniform mechanical properties throughout the entire pipe cross-section.
High-Temperature Strength: Maintains excellent mechanical properties up to 550°C (1020°F). Nickel content ensures stability and combats chloride stress corrosion at elevated temperatures.
Titanium Stabilization: The addition of titanium prevents sensitization of grain boundary precipitates, making the alloy highly resistant to intergranular corrosion — even after welding and heat cycles.
Marine & Seawater Resistant: Copper-bearing alloy with strong resistance to seawater, brine solutions, and marine environments — ideal for offshore platforms, desalination, and subsea applications.
Easy Fabrication: Hot-working range of 870–1180°C. Cold-forming easier than most stainless steels. Compatible with GTAW, GMAW, and SMAW welding processes without pre-heat requirements.

Manufacturing Process

Incoloy 825 seamless pipes are produced through a carefully controlled multi-stage process to ensure chemical uniformity, dimensional precision, and maximum corrosion performance.

Billet Preparation

Solid N08825 billet cast and inspected for chemical homogeneity

Hot Extrusion

Billet extruded at 870–1180°C to form seamless hollow tube

Cold Drawing

Cold-drawn to achieve precise OD, wall thickness & surface finish

Solution Annealing

Annealed and rapidly cooled for optimum corrosion resistance

Testing & Inspection

Hydrostatic, eddy current, tensile, hardness & dimensional tests

Specifications of Incoloy 825 Seamless Pipes

Specification	Details
Standard	ASTM B423, ASME SB423, ASTM B163, ASME SB163
UNS Designation	N08825
Werkstoff Nr.	2.4858
Outer Diameter	4.0 mm – 1219.2 mm (1/2" – 48")
Wall Thickness	0.5 mm – 50 mm
Pipe Size	1/2" NB – 24" NB
Schedule	SCH 5S, SCH 10, SCH 10S, SCH 20, SCH 40, SCH 40S, STD, SCH 60, XS, SCH 80, SCH 80S, SCH 120, SCH 160, XXS
Type	Seamless (Hot Finished, Cold Drawn)
Form	Round, Square, Rectangular, Hex
Length	Single Random (SRL), Double Random (DRL), Fixed / Cut Length
End Finish	Plain End (PE), Beveled End (BE), Threaded
Supply Condition	Solution Annealed + Rapid Cooled
Finish	Bright Annealed, Pickled, Polished (EP/MP)

Incoloy 825 Seamless Pipe Equivalent Grades

Standard	UNS	Werkstoff Nr.	JIS	BS	AFNOR	EN
Incoloy 825	N08825	2.4858	NCF 825	NA 16	NFE30C20DU	NiCr21MoXH38BT

Chemical Composition of ASTM B423 UNS N08825

Element	Min (%)	Max (%)	Role in Alloy
Nickel (Ni)	38.00	46.00	Stress corrosion cracking resistance; heat stability
Chromium (Cr)	19.50	23.50	Oxidation and corrosion resistance
Iron (Fe)	22.00	—	Base structural element
Molybdenum (Mo)	2.50	3.50	Pitting and crevice corrosion resistance
Copper (Cu)	1.50	3.00	Reducing acid and seawater resistance
Titanium (Ti)	0.60	1.20	Stabilizes against intergranular corrosion
Carbon (C)	—	0.05	Max — controlled to prevent sensitization
Manganese (Mn)	—	1.00	Deoxidizer
Silicon (Si)	—	0.50	Deoxidizer
Sulfur (S)	—	0.03	Max — minimized for weldability
Aluminum (Al)	—	0.20	Deoxidizer

Mechanical & Physical Properties of B423 UNS N08825 Pipes

Property	Imperial	Metric
Tensile Strength (min.)	85 ksi (585 MPa)	585 MPa
Yield Strength 0.2% (min.)	30 ksi (205 MPa)	205 MPa
Elongation (min.)	30%	30%
Hardness	≤ 200 HB	≤ 200 HB
Density	0.294 lb/in³	8.14 g/cm³
Melting Range	2370–2550 °F	1300–1400 °C
Max Service Temperature	1020 °F	550 °C
Thermal Conductivity (21°C)	6.7 BTU/hr·ft·°F	11.1 W/m·K
Coefficient of Thermal Expansion	7.8 μin/in·°F	14.0 μm/m·°C

Applicable Standards

Solitaire Overseas supplies Incoloy 825 seamless pipes in compliance with the following international standards:

All pipes are supplied with EN 10204 3.1 Mill Test Certificates as standard. Third-party EN 10204 3.2 inspection and NACE MR0175 compliance documentation available on request.

Applicable Standards

Our Incoloy 825 welded pipes are manufactured and supplied in compliance with the following international specifications:

ASTM B423 ASME SB423 ASTM B163 ASME SB163 DIN 17751 ISO 6207 EN 10216-5 NACE MR0175 ASME B36.19M

All pipes are supplied with EN 10204 3.1 Mill Test Certificates as standard. Third-party EN 10204 3.2 inspection and NACE MR0175 compliance documentation available on request.

Pressure Ratings of ASTM B423 Incoloy 825 Seamless Pipes

Working pressure varies with OD and wall thickness. Values below are in psig at ambient temperature.

NPS	OD (in)	Schedule	Wall Thickness (in)	Working Pressure (psig)
1/2"	0.840	SCH 40 STD	0.109	6,530
1/2"	0.840	SCH 80 XS	0.147	9,730
3/4"	1.050	SCH 40 STD	0.113	5,690
3/4"	1.050	SCH 80 XS	0.154	8,360
1"	1.315	SCH 40 STD	0.133	5,310
1"	1.315	SCH 80 XS	0.179	7,640
1-1/2"	1.900	SCH 40 STD	0.145	4,010
1-1/2"	1.900	SCH 80 XS	0.200	5,870
2"	2.375	SCH 40 STD	0.154	3,400
2"	2.375	SCH 80 XS	0.218	5,040
3"	3.500	SCH 40 STD	0.216	3,240
3"	3.500	SCH 80 XS	0.300	4,720
4"	4.500	SCH 40 STD	0.237	2,760
4"	4.500	SCH 80 XS	0.337	4,100

Schedule & Wall Thickness Chart for UNS N08825 Incoloy 825 Seamless Pipe

Nominal Size	OD (in)	SCH 10 (in)	SCH 40/STD (in)	SCH 80/XS (in)	SCH 160 (in)	XXS (in)
1/2"	0.840	0.083	0.109	0.147	0.188	0.294
3/4"	1.050	0.083	0.113	0.154	0.219	0.308
1"	1.315	0.109	0.133	0.179	0.250	0.358
1-1/4"	1.660	0.109	0.140	0.191	0.250	0.382
1-1/2"	1.900	0.109	0.145	0.200	0.281	0.400
2"	2.375	0.109	0.154	0.218	0.344	0.436
3"	3.500	0.120	0.216	0.300	0.438	0.600
4"	4.500	0.120	0.237	0.337	0.531	0.674
6"	6.625	0.134	0.280	0.432	0.719	0.864
8"	8.625	0.148	0.322	0.500	0.906	0.875

Weight Chart for Incoloy 825 Seamless Pipe (NPS vs. Schedule, kg/m)

NPS	OD (mm)	SCH 40 STD (kg/m)	SCH 80 XS (kg/m)	SCH 160 (kg/m)
1/2"	21.3	1.27	1.62	2.55
3/4"	26.7	1.69	2.20	3.64
1"	33.4	2.50	3.24	5.44
1-1/2"	48.3	4.05	5.41	8.10
2"	60.3	5.44	7.48	13.44
3"	88.9	11.29	15.27	22.32
4"	114.3	16.07	22.32	35.11

Dimensional Tolerances — ASTM B423 Incoloy 825 Seamless Pipe

Parameter	Tolerance	Standard Reference
Outer Diameter (OD) — up to 38.1mm	± 0.127 mm	ASTM B423
Outer Diameter (OD) — 38.1 to 50.8mm	26.7	ASTM B423
Outer Diameter (OD) — over 50.8mm	± 0.8%	ASTM B423
Wall Thickness	+ 20% / -0%	ASTM B423
Length (Fixed/Cut)	+ 6mm / -0mm	ASME SB423
Straightness	3.2mm per 3m	ASTM B423

Applications of Incoloy 825 Seamless Pipes

The combination of seamless construction and the superior corrosion properties of UNS N08825 makes these pipes the first choice for mission-critical applications across a wide range of industries:

Chemical Processing: Sulfuric acid pickling, acid regeneration, phosphoric acid plants
Oil & Gas Extraction: Sour gas service, downhole tubing, wellhead equipment
Nuclear Fuel Reprocessing: Storage tanks, piping for radioactive materials handling
Offshore Platforms: Seawater injection, subsea umbilicals, topside process piping
Pollution Control: Flue gas desulfurization scrubbers, stack gas systems
Heat Exchangers: Shell-and-tube heat exchangers in corrosive fluid service
Desalination Plants: Brine evaporators, multi-stage flash distillation systems
Power Generation: Condenser tubing, flue gas handling, high-pressure steam lines
Petroleum Refining: High-pressure hydrotreating, catalytic reforming units
Radioactive Waste Handling: Containment vessels, transfer piping in nuclear facilities