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Material: Incoloy 800, 800H, 800HT, 825
Type: Plate, Sheet, Strip and Coil
Thickness: 0.3-1200mm, customized
Width: 0-2500mm, customized
Length: 0-12m, customized
Surface: No.1 No.2D No.2B BA No.3 No.4 No.6 No.7, etc
Incoloy sheet plate is a flat-rolled product manufactured from the Incoloy family of iron-nickel-chromium alloys - a class of austenitic heat-resistant alloys designed for service in temperatures ranging from cryogenic to 1000 deg C.
Type | Plate, Sheet, Strip, Coil | |
|---|---|---|
Surface | No.1 No.2D No.2B BA No.3 No.4 No.6 No.7 | |
Size | Width: 0-2500mm / Customized | |
Manufacturing Technique | Hot / Cold Rolled | |
Packing | Steel Frame, waterproof paper, wooden palet, wooden case or as per the dient's requirements | |
Incoloy Grades | Incoloy 800, 800H, 800HT, 825 | |
Incoloy sheet plate is categorised by the rolling process and dimensional range. Three primary product forms are available, each serving distinct fabrication and performance requirements:
Sheet Type | Thickness Range | Width Range | Manufacturing Process |
Hot-rolled (HR) - Plate | 4.76-75 mm (3/16" to 3") | 900-3,000 mm | Slab reheated to 1050-1200 deg C; hot-rolled through reversing mill or Steckel mill; descaled by shotblasting and pickling (HNO3-HF acid bath); supplied as plate or sheared lengths 2,000-12,000 mm |
Cold-rolled (CR) - Sheet | 0.3-6.35 mm (0.012" to 1/4") | 600-1,500 mm | Hot-rolled strip pickled and cold-reduced through tandem cold mill (30-90% thickness reduction per pass); annealed in protective N2-H2 atmosphere for bright surface; temper-rolled for flatness; supplied as sheet or coil |
Cold-rolled - Strip / Coil | 0.1-3.0 mm (0.004" to 0.120") | 20-600 mm | Continuous cold rolling from hot-rolled coil; intermediate annealing between passes; slit to specified width; supplied in coil form or cut-length strip; optional edge rolled or edge milled |
We supply four principal Incoloy® grades are commercially available in sheet and plate form. They divide into two functional clusters: the high-temperature 800 series and the corrosion-resistant 825.
Element | 800 (N08800) | 800H (N08810) | 800HT (N08811) | 825 (N08825) |
Ni (%) | 30.0 – 35.0 | 30.0 – 35.0 | 30.0 – 35.0 | 38.0 – 46.0 |
Fe (%) | ≥ 39.5 | ≥ 39.5 | ≥ 39.5 | ≥ 22.0 |
Cr (%) | 19.0 – 23.0 | 19.0 – 23.0 | 19.0 – 23.0 | 19.5 – 23.5 |
Mo (%) | — | — | — | 2.5 – 3.5 |
Cu (%) | — | — | — | 1.5 – 3.0 |
Ti (%) | 0.15 – 0.60 | 0.15 – 0.60 | 0.15 – 0.60 | 0.6 – 1.2 |
Al (%) | 0.15 – 0.60 | 0.15 – 0.60 | 0.25 – 0.60 (Al+Ti = 0.85–1.20) | ≤ 0.2 |
C (%) | ≤ 0.10 | 0.05 – 0.10 | 0.06 – 0.10 | ≤ 0.05 |
Mn (%) | ≤ 1.50 | ≤ 1.50 | ≤ 1.50 | ≤ 1.0 |
Si (%) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 | ≤ 0.5 |
Nb (%) | — | — | — | — |
S (%) | ≤ 0.015 | ≤ 0.015 | ≤ 0.015 | ≤ 0.03 |
Property | 800 | 800H | 800HT | 825 |
UTS (MPa) | ≥ 520 | ≥ 520 | ≥ 520 | ≥ 585 |
0.2% Yield (MPa) | ≥ 205 | ≥ 205 | ≥ 205 | ≥ 240 |
Elongation (%) | ≥ 30 | ≥ 30 | ≥ 30 | ≥ 30 |
Hardness (HBW) | ≤ 200 | ≤ 200 | ≤ 200 | ≤ 200 |
Condition | Annealed | Solution annealed | Solution annealed | Annealed |
Physical Property | 800/800H/800HT | 825 |
Density (g/cm³) | 8.00 | 8.14 |
Melting Range (°C) | 1 350 – 1 400 | 1 370 – 1 425 |
Thermal Conductivity (W/m·K) | 12.5 (at 20 °C) | 11.1 (at 20 °C) |
Coeff. Thermal Expansion (µm/m·°C) | 14.4 (20–100 °C) | 14.0 (20–100 °C) |
Elastic Modulus (GPa) | 196 | 196 |
Electrical Resistivity (µΩ·cm) | 99 | 113 |
Max Service Temp (°C) | 1 150 (oxidizing) | 540 (aqueous) |
The table below details the primary incoloy sheet plate standards applicable to sheets and plates, as well as their global equivalents.
Standard | Scope | Grade(s) Covered | Product Form | Key Requirements |
ASTM B409-21 | Nickel-Iron-Chromium Alloy Plate, Sheet, Strip | 800, 800H, 800HT | Plate / Sheet / Strip | Chemistry, UTS ≥ 520 MPa, elongation ≥ 30%; grain-size per 800H/800HT |
ASTM B424-20 | Ni-Fe-Cr-Mo-Cu Alloy Plate, Sheet, Strip | 825 | Plate / Sheet / Strip | Chemistry, UTS ≥ 585 MPa, yield ≥ 240 MPa, elongation ≥ 30% |
ASME SB-409 | ASME adoption of ASTM B409 | 800, 800H, 800HT | Plate / Sheet | Pressure Vessel Code compliance (Section II, Part B) |
ASME SB-424 | ASME adoption of ASTM B424 | 825 | Plate / Sheet | Pressure Vessel Code compliance (Section II, Part B) |
EN 10095:1999 | Heat-resisting steels and nickel alloys | 800 / 800H / 800HT | Plate / Sheet | European equivalent; provides alloy 1.4876 (800) and 1.4958 (800H) |
ISO 6208:2014 | Nickel alloy strip and sheet — tolerances | All | Strip / Sheet | Dimensional tolerances and flatness requirements for Ni-alloy sheet |
Grade | ASTM / UNS | ASME | EN / W.Nr. | ISO | DIN | JIS |
Incoloy 800 | ASTM B409 / N08800 | SB-409 | 1.4876 / EN 10095 | NW 8800 | DIN 17459 | NCF 800 |
Incoloy 800H | ASTM B409 / N08810 | SB-409 | 1.4958 / EN 10095 | NW 8810 | DIN 17459 | NCF 800H |
Incoloy 800HT | ASTM B409 / N08811 | SB-409 | 1.4959 / EN 10095 | NW 8811 | DIN 17459 | — |
Incoloy 825 | ASTM B424 / N08825 | SB-424 | 2.4858 / ISO 9723 | NW 8825 | — | NCF 825 |
Q1. What is the difference between Incoloy 800, 800H, and 800HT?
All three are Ni-Fe-Cr alloys (UNS N08800/N08810/N08811) with nearly identical chemistry. The key distinction is carbon content and Al+Ti constraint: Incoloy 800 (C ≤ 0.10%) is the base alloy; 800H raises carbon to 0.05–0.10% and specifies a minimum ASTM grain-size number ≥ 5 to maximise creep strength; 800HT further restricts Al+Ti to 0.85–1.20% to optimise long-term high-temperature stability. At 900 °C/10 000 hours, 800HT shows 15–20% higher creep-rupture strength than 800H.
Q2. Can Incoloy 825 replace 316L stainless steel in seawater service?
Yes — and in most cases it is the superior choice. Incoloy 825 has a PREN (Pitting Resistance Equivalent Number) of approximately 30 vs. ~23 for 316L, and is essentially immune to chloride stress-corrosion cracking (SCC) — the primary failure mode of 316L in warm seawater above 50 °C. For offshore heat exchangers and desalination evaporators exposed to seawater > 60 °C, Incoloy 825 per ASTM B424 is the definitive recommendation.
Q3. Is Incoloy 925 approved for NACE sour-service applications?
Yes. Incoloy 925 (UNS N09925) is listed in NACE MR0175/ISO 15156-3 as a qualified material for H₂S-containing oilfield service. In the age-hardened condition, it must meet a maximum hardness of 35 HRC (352 HBW) and a maximum UTS per the declared strength condition. It combines the sour-service corrosion resistance of Incoloy 825 with precipitation-hardened strength (UTS up to 1 210 MPa), making it the preferred choice for high-pressure downhole components and wellhead tubing hangers.
Q4. What makes Alloy 20 (Incoloy 020) uniquely suited for sulfuric acid service?
Alloy 20 (UNS N08020) contains 3–4% copper, which stabilises the alloy's passive film in reducing acidic environments and suppresses hydrogen evolution. Combined with its niobium stabilisation (Nb ≥ 8×C), it resists intergranular attack after welding. Corrosion rate data shows Alloy 20 survives 50% H₂SO₄ at 80 °C — conditions that produce >10 mm/year corrosion in 316L and even challenge 904L stainless steel.
Q5. What grain size is required for Incoloy 800H to meet ASME pressure vessel code creep service?
ASTM B409-21 and ASME SB-409 specify that Incoloy 800H sheet must have an ASTM grain size number of 5 or coarser (i.e., larger grains, equivalent to ≤ 0.063 mm average grain diameter). Coarser grain size improves creep-rupture resistance by reducing grain-boundary sliding at elevated temperature. This is verified by metallographic examination per ASTM E112.
Q6. What certifications should I require when purchasing Incoloy sheet for pressure vessel construction?
At minimum, require: (1) EN 10204 Type 3.1 Mill Test Report — confirming actual chemical and mechanical test results on the production heat; (2) ASME Material Certification — confirming compliance with ASME SB-409/SB-424/SB-463 as applicable; (3) Pressure Equipment Directive (PED 2014/68/EU) declaration if used in EU-regulated pressure vessels; and (4) For sour-gas service, a NACE MR0175/ISO 15156-3 Compliance Letter identifying hardness limits and heat-treatment conditions.
