INCOLOY 825

Incoloy 825 is a nickel-iron-chromium alloy containing molybdenum, copper, and titanium. It offers enhanced corrosion resistance in both mildly oxidizing and reducing environments, providing superior protection compared to alloy 800, particularly against aqueous corrosion.

Specifications

Standard/Code	Specification Details
BS 3076 NA16	2.4858, NFe 32 C 20 DU, NiCr 21 Mo
ASTM B425	UNS N08825
API 6CRA 825	Incoloy 825 for corrosion-resistant alloy applications

Characteristics

Composition: An austenitic nickel-iron-chromium alloy with molybdenum, copper, and titanium additions.

Corrosion Resistance: Excellent resistance to both oxidizing and reducing environments. It resists chloride stress-corrosion cracking, pitting, and intergranular attack.

Chemical Resistance: Highly resistant to sulfuric, sulfurous, phosphoric, nitric, hydrofluoric acids, alkalis, and acidic chloride solutions.

Fabrication: Easily formable and weldable by various techniques, typical of nickel-based alloys. Titanium stabilizes the alloy to prevent sensitization during welding.

Standards

ASTM B425

–Plate, Sheet, and Strip–

ASTM B564

–Forgings–

ASME SB 425

–plate, sheet, and strip–

ASTM B619

–Welded Pipe & Tube–

DIN

17752

–German standard–

ISO

9723

–International standards–

In Stock

Feel free to reach out if you require customized services. We will provide you with pricing and availability within 24 hours.

QUOTE NOW

Data Sheet

Chemical Composition

Element	Min	Max
Nickel + Cobalt	38.0%	46.0%
Cobalt	—	2.00%
Chromium	19.5%	23.5%
Copper	1.50%	3.00%
Iron	22.0%	—
Silicon	—	0.50%
Manganese	—	1.00%
Carbon	—	0.05%
Aluminum	—	0.20%

Physical Properties

Property	Value
Density	0.294 lbs/in³ (8.14 g/cm³)
Specific Heat (32 – 212 °F)	0.105 Btu/lb·°F (440 J/kg·°C)
Mean Coefficient of Thermal Expansion	7.7 x 10⁻⁵ in/in·°F (13.9 mm/m·°C) from 70 – 212 °F (20 – 100 °C)
Thermal Conductivity	6.4 BTU/h·ft·°F (11.1 W/m·K) at 70 °F (21 °C)
Modulus of Elasticity	28.4 x 10³ ksi (196 x 10³ MPa) in tension
Magnetic Permeability at 70 °F (21 °C)	Annealed: 1.005 H = 200 Oersted
Melting Point	2500 – 2550 °F (1370 – 1400 °C)

Corrosion Resistance

General Corrosion Resistance

- Excellent resistance to both oxidizing and reducing environments.
- Effectively resists general corrosion in a wide range of conditions.

Localized Corrosion Resistance

- Provides strong protection against pitting and crevice corrosion.
- Resists intergranular corrosion, even in harsh environments.

Stress Corrosion Cracking (SCC)

- Outstanding resistance to chloride-induced stress corrosion cracking, which is common in marine and chemical processing applications.

Performance in Specific Environments

- Sulfuric Acid: Superior resistance across various concentrations, as demonstrated in laboratory testing.
  - Corrosion rate in boiling laboratory sulfuric acid solutions:
    - 10% concentration: 20 mils/year (0.5 mm/year)
    - 40% concentration: 11 mils/year (0.28 mm/year)
    - 50% concentration: 20 mils/year (0.5 mm/year)
- Phosphoric Acid: Excellent resistance, making it suitable for fertilizer production and chemical applications.
- Sulfur-Containing Flue Gases: Highly resistant in environments with sulfur-based compounds.
- Sour Gas and Oil Wells: Effectively resists corrosion in hydrogen sulfide (H₂S)-rich environments.
- Sea Water: Provides long-term durability against the corrosive effects of chloride-rich marine environments.

Comparison with Other Alloys

- Outperforms 316 stainless steel in boiling sulfuric acid, with significantly lower corrosion rates.
- Comparable to Inconel® 625 in many environments but with unique advantages in sulfuric acid solutions.

Mechanical Properties(Room Temperature)

Property	Value	Unit
0.2% Proof Stress	241	N/mm² (35 ksi)
Tensile Strength	590	N/mm² (86 ksi)
Elongation (5.65√S₀ or 4D)	30	%
Reduction of Area	40	%
Hardness (Brinell)	327 (max.)	HB

Mechanical Properties(Elevated Temperature)

Property	Condition	Value	Unit
Compressive Yield Strength	Annealed at 1725°F (940°C) for 1 hour	423	MPa (61,400 psi)
Ultimate Tensile Strength	Annealed at 1725°F (940°C) for 1 hour	720	MPa (104,500 psi)
Temperature Limit for Usage	Avoided above	540	°C (1000°F)
Ductility and Impact Strength	Reduced above	540	°C (1000°F)

Welding and Fabrication

Welding

Compatibility
- Incoloy® 825 is compatible with a variety of welding, brazing, and soldering techniques.
- For best practices, refer to SSINA’s “Welding of Stainless Steels and Other Joining Methods.”
Performance in Welding
- Ensures excellent joint integrity and maintains the alloy’s corrosion resistance.
- Suitable for welding applications requiring strength and durability in challenging environments.
Expert Guidance
- Specialized resources are available to assist with welding techniques to ensure optimal results.

Fabrication

Heat Treatment

- During manufacturing, Incoloy® 825 is heat treated to optimize stabilization, corrosion resistance, mechanical properties, and formability.
- For subsequent fabrication:
  - Annealing should be performed at 1700–1800°F (930–980°C).
  - Rapid air cooling or water quenching is recommended after annealing for thicker cross-sections.
  - Lower temperature annealing ensures stabilization, while higher temperature annealing enhances softness and grain structure, ideal for forming and deep drawing.

Quenching
- Not necessary for thin cross-section products (e.g., sheets, strips, wires).
- Recommended for heavier cross-sections to prevent sensitization and maintain corrosion resistance.
General Fabrication Processes
- Heating, forming, pickling, and finishing procedures should follow industry best practices.
- Refer to the SMC bulletin “Fabricating” for comprehensive guidance.

Applications

Customized Package

Oil-coated paper wraps our plates, providing protection against corrosion.
Plates are placed on wooden pallets and strapped to secure them, preventing shifting during transportation.

Thick woven plastic bags are used to bundle several bars and rods together.
Each bundle is carefully packed, with the weight not exceeding 1500 KG for safe handling.

Tubes and pipes are packed in air cushion film to shield them from dirt and scratches.
For extra protection, they are placed in wooden cases to prevent damage during transit.

Logistics

At AlloyXpert, sea transportation is the most commonly used method for the majority of our orders and is considered the default shipping mode. Therefore, our quotations are typically based on FOB, CFR, or CIF terms. For customers with urgent requirements, we also offer air transportation as an expedited shipping option. Please feel free to reach out for customized solutions based on your delivery needs.

Related Products

ASTM B424

Inconel 625

Hastelloy C276

Monel 400

MAKE AN ENQUIRY

Complete the form below to make an enquiry or request a quote and one of our team will get back to you shortly.