ASTM B424 Alloy 825 Plate | UNS N08825 | Incoloy 825

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies Nickel Alloy 825, also known as Incoloy 825, identified as UNS N08825 and Werkstoff 2.4858 (EN designation NiCr21Mo), in plate, sheet, and strip form according to ASTM B424 / ASME SB-424.

Nickel Alloy 825 is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium, designed to provide exceptional resistance to many corrosive environments. The nickel content (38-46%) is sufficient for resistance to chloride-ion stress-corrosion cracking, while the nickel, molybdenum, and copper together provide outstanding resistance to reducing environments such as sulfuric and phosphoric acids. The chromium content (19.5-23.5%) confers resistance to oxidizing substances such as nitric acid and oxidizing salts, and the titanium addition stabilizes the alloy against sensitization to intergranular corrosion. The alloy is readily fabricated, welded, and formed, and is not age-hardenable.

Composition per ASTM B424 requirements.

Actual properties depend on product form, dimensions, and heat-treatment condition.

Annealed

Alloy 825 plate is normally supplied in the annealed condition. The standard annealing treatment is performed at approximately 1,832°F (1,000°C) followed by rapid cooling. This treatment provides optimal corrosion resistance and ductility. The titanium addition stabilizes the alloy against sensitization to intergranular corrosion.

Cold Working

Alloy 825 is not age-hardenable – strength increases only through cold working. Annealed plate exhibits tensile strength of approximately 96 ksi (662 MPa) with 45% elongation.

Temperature Limitation: Exposure to temperatures above about 1,000°F (540°C) can result in microstructural changes (phase formation) that significantly lower ductility and impact strength, so the alloy is not normally used where creep-rupture properties are design factors.

Alloy 825 provides exceptional resistance to many corrosive environments.

Key Corrosion Characteristics:

• Excellent resistance to sulfuric and phosphoric acids of various concentrations
• Good resistance to nitric acid – better than ASTM 316L
• Excellent resistance to chloride stress-corrosion cracking due to nickel content above 40%
• Superior pitting and crevice corrosion resistance compared to molybdenum-alloyed stainless steels such as ASTM 316L
• Titanium stabilization prevents sensitization and intergranular corrosion in the as-welded condition
• Good resistance to seawater, caustic alkalis, and ammoniac
• Approved for sour service per NACE MR0175 / ISO 15156 in annealed and cold-worked conditions

Selection Considerations:

• Superior to standard molybdenum-alloyed stainless steels such as 316L, particularly in non-oxidizing media
• For more aggressive environments requiring higher Ni and Mo content, Alloy G-3 or C-276 may be preferred
• Not recommended for service above 540°C where creep-rupture properties are required
• Final selection must consider the specific medium, concentration, temperature, and exposure conditions

• Chemical Processing: Reactors, heat exchangers, evaporators, piping for sulfuric and phosphoric acid environments
• Oil and Gas: Sour gas well components, off-shore piping systems, flanges, valves
• Pollution Control: Flue gas desulfurization equipment, waste incineration systems
• Pickling Operations: Pickling tank equipment
• Nuclear: Fuel reprocessing, radioactive waste handling
• Pulp and Paper: Digesters, bleach plants

Available quality-control services include:

• Heat-number traceability
• Chemical composition verification
• Tensile, yield and elongation testing
• Hardness inspection
• Dimensional and surface inspection
• Positive Material Identification (PMI)
• Ultrasonic testing
• Dye penetrant inspection
• Heat-treatment records
• EN 10204 3.1 material certificate

For an accurate quotation, please provide:

Alloy Grade · Standard · Product Form · Dimensions (Thickness × Width × Length) · Quantity · Surface Finish · Inspection Requirement · Application · Working Temperature · Destination Port

For corrosive environments, also provide:

Chemical Medium · Concentration · Temperature · Oxidizing or Reducing Conditions

• Request ASTM B424 Alloy 825 Plate Quote
• Upload Drawing or MTO
• Check Available Stock
• Ask for Alloy Selection Support