Introduction

Incoloy 825 (UNS N08825 / Alloy 825 / W.Nr. 2.4858) is a nickel-iron-chromium alloy with added molybdenum, copper, and titanium, designed for exceptional corrosion resistance in both oxidizing and reducing environments. Incoloy 825 seamless tube, pipe, heat exchanger tube, round bar, sheet, plate, strip, welding wire, forging, flange, and fitting are widely used in chemical processing equipment, flue gas desulfurization systems, oil and gas piping, marine heat exchangers, acid pickling tanks, and offshore platforms. This alloy offers outstanding resistance to sulfuric acid, phosphoric acid, chloride stress corrosion cracking, pitting, and seawater corrosion. It performs reliably at temperatures up to 550°C. Available per ASTM B423, B424, B425, B163, or customer specifications.

Chemical components （%）

Mechanical properties

Physical properties

Incoloy 825 Available Products and Standard

1. GB/T 15007 (Nickel and Nickel Alloy Plate, Strip, and Foil)

Domestic Grade: NS142 (GB/T 15007) / Incoloy 825 equivalent

Type: Wire / Strip / Bar / Sheet / Seamless Tube / Pipe / Forgings

Size Range:

• Incoloy 825 Wire: 0.1 – 15.0 mm dia

• Incoloy 825 Strip: 0.05 – 5.0 mm thick × 5 – 500 mm wide

• Incoloy 825 Round Bar: 8 – 355 mm dia

• Incoloy 825 Sheet / Plate: 0.5 – 180 mm thick

• Incoloy 825 Seamless Tube / Pipe: Custom sizes available

Surface: Annealed, Bright, Pickled, Ground

Testing: Chemical analysis, mechanical test (tensile strength, yield strength, elongation), hardness test, intergranular corrosion test, pitting corrosion test, dimensional inspection

2. ASTM B423 (Standard Specification for Nickel-Iron-Chromium-Molybdenum-Copper Alloy Seamless Pipe and Tube)

Grade: UNS N08825 / Incoloy 825 / Alloy 825 / W.Nr. 2.4858

Type: Seamless Pipe / Seamless Tube / Heat Exchanger Tube

Size Range:

• Incoloy 825 Seamless Pipe: 6 – 610 mm OD × 1 – 50 mm wall thickness

• Incoloy 825 Seamless Tube: Custom sizes

Surface: Annealed, Pickled, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hydrostatic test, eddy current test, corrosion test (sulfuric acid), dimensional inspection

3. ASTM B424 (Standard Specification for Nickel-Iron-Chromium-Molybdenum-Copper Alloy Plate, Sheet, and Strip)

Grade: UNS N08825 / Incoloy 825 / Alloy 825

Type: Sheet / Plate / Strip

Size Range:

• Incoloy 825 Sheet / Plate: 0.5 – 180 mm thick (hot rolled or cold rolled)

• Incoloy 825 Strip: 0.05 – 5.0 mm thick × up to 500 mm wide (coils)

Surface: Annealed, Pickled, Bright, Polished

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, intergranular corrosion test, pitting corrosion test, dimensional inspection

4. ASTM B425 (Standard Specification for Nickel-Iron-Chromium-Molybdenum-Copper Alloy Rod and Bar)

Grade: UNS N08825 / Incoloy 825 / Alloy 825

Type: Round Bar / Rod / Wire

Size Range:

• Incoloy 825 Round Bar: 8 – 355 mm dia (hot rolled or cold drawn)

• Incoloy 825 Wire: 0.1 – 15.0 mm dia (coils or straight)

Surface: Annealed, Pickled, Ground, Turned, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, ultrasonic test, dimensional inspection

5. Additional Standards (upon request)

• ASTM B163 – Seamless Condenser and Heat Exchanger Tube

• ASTM B564 – Forgings / Forged Ring / Flange

• ASTM B366 – Fittings (elbows, tees, reducers)

• ASME SB423 / SB424 / SB425 – Boiler and Pressure Vessel Code

Testing for additional products: Chemical analysis, mechanical test, hardness test, PMI (positive material identification), ultrasonic test, dimensional inspection

Advantages

(1)Outstanding sulfuric and phosphoric acid resistance: Incoloy 825 seamless tube and plate perform exceptionally well in hot sulfuric acid and phosphoric acid environments, even when contaminated with chlorides or fluorides.

(2)Excellent chloride stress corrosion cracking resistance: The high nickel content (38–46%) gives Alloy 825 round bar and pipe superior resistance to SCC in marine and chemical processing applications.

(3)Good pitting and crevice corrosion resistance: Molybdenum and copper additions enable Incoloy 825 sheet and strip to withstand seawater, brine, and chloride-containing media.

(4)Stable in both oxidizing and reducing acids: This nickel-iron-chromium alloy performs reliably in nitric acid (oxidizing) as well as dilute sulfuric acid (reducing), offering versatile corrosion protection.

(5)Good weldability and fabricability: Incoloy 825 welding wire and filler rod produce sound joints, and the alloy can be readily formed into heat exchanger tubes, flanges, and fittings for complex equipment.

Applications

(1)Chemical processing equipment – Incoloy 825 plate and seamless pipe are used in reactors, evaporators, and pickling tanks handling sulfuric acid, phosphoric acid, and organic acids.

(2)Flue gas desulfurization (FGD) systems – Alloy 825 heat exchanger tube and strip resist chloride attack and pitting in scrubbers, ductwork, and stack liners for power plants.

(3)Oil and gas piping – Incoloy 825 seamless tube and fitting are specified for downhole tubing, flow lines, and sour gas service where H₂S and chlorides are present.

(4)Marine and offshore platforms – Incoloy 825 round bar and fastener serve in seawater piping, pumps, valves, and platform risers requiring resistance to uniform and localized corrosion.

(5)Nuclear fuel reprocessing – Alloy 825 welding wire and plate are used in dissolvers and waste treatment systems for spent nuclear fuel, where nitric and hydrofluoric acid mixtures are handled.

(6)Pharmaceutical and food processing – Incoloy 825 sheet and tube provide corrosion resistance in digesters, fermenters, and heat exchangers for high-purity applications.

MONO Group is one of Superalloy, Nickel alloy, high Temperature alloy manufacturer&Supplier&Wholesaler from China,We can supply high quality alloy plate,sheet,round bar,tube.pipes,fittings,flange,and custom parts in accordance with ASTM, ASME, DIN, ISO, GB, and other international standards. For inquiries or to request a quote , please freely contact us at info@monokj.com.