Bar and Rod
Plate and Sheet
Strip
Pipe and Tube
Wire
Welding
Powder Material
Cast Products
Forged Products
Fittings
Fastening
Round Bar:
φ2–500 mm, 1–6 m length
Flat/Square Bar:
4–100 mm thickness/width
Hex Bar:
A/F 3–100 mm
Hollow Bar:
OD 20–300 mm
Sheet:
0.3–6 mm thickness
Medium Plate:
6–25 mm thickness
Heavy Plate:
25–100 mm thickness
Standard Strip:
0.05–3 mm thick,
10–600 mm wide
Precision strip:
0.01–0.5 mm thick,
tight tolerance ±0.005 mm
Foil:
0.005–0.1 mm thick
Seamless Tube:
OD 6–450 mm,
WT 1–50 mm,
1–12 m length
Welded Tube:
OD 10–600 mm,
WT 1–20 mm
Capillary Tube:
OD 1–10 mm,
WT 0.1–2 mm
Wire Form:
Cold Drawn Wire,
Bright Wire,
Spring Wire,
Fine Wire,
Ultra-fine Wire
General Diameter:
φ0.1–10 mm
Coil Weight:
50–500 kg,
customizable tolerance
Solid Wire:
φ0.8–4.0 mm
Flux-cored Wire:
φ1.2–4.0 mm
Welding Rod:
φ2.0–5.0 mm
Powder Form:
AM 3D Printing Powder,
Spherical Powder,
Gas-atomized Powder,
Water-atomized Powder
Particle Size:
10–150 μm
Sphericity:
≥90% for AM grade
Cast Ingot:
φ200–800 mm
Precision Casting:
min wall 0.5 mm
Cast Pipe:
OD 100–600 mm,
WT 10–50 mm
Forged Bar:
Φ35–500 mm
Forged Ring:
OD 200–2000 mm
Forging Weight:
1–5000 kg
Fittings Form:
Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint
Size range:
1/2''–24'' (DN15–DN600)
Wall thickness:
Sch10–Sch160, STD, XS, XXS
Pressure Class:
150–2500 LB
Fastening Form:
Bolt, Nut, Screw, Stud, Washer, Pin, Rivet
Metric: M3–M64
Imperial: #4–2.5''
Length: 6–500 mm
Alloy 803 is an iron–nickel–chromium alloy designed for petrochemical, chemical and thermal-processing applications. This datasheet presents the material within the American (ASTM / ASME / UNS) standard system.
Its nickel and chromium contents are higher than those of the 800H / 800HT grades, and the ratios of nickel, iron and chromium are balanced to give optimum properties in the 840–1150 °C (1550–2100 °F) range. It is a cost-effective material providing an exceptional level of high-temperature corrosion resistance in oxidation, sulfidation and carburisation environments, together with excellent stress-rupture strength at elevated temperatures.
These characteristics — high resistance to carburisation and cyclic oxidation combined with high creep-rupture strength — make it the material of choice for many severe applications, notably ID-finned pyrolysis tubing in high-severity ethylene furnaces. Like the other 800-series alloys it shows good resistance to chloride stress-corrosion cracking, but can be sensitised by exposure to 540–760 °C; solution annealing restores ductility after long high-temperature exposure.
Values per Special Metals official datasheet, annealed condition.
| Property | Value | Unit |
|---|---|---|
| Density | 7.86 | g/cm³ |
| Melting range | 1365–1400 | °C |
| Young's modulus (20 °C) | 195 | GPa |
| Shear modulus (20 °C) | 73.8 | GPa |
| Poisson's ratio (20 °C) | 0.32 | — |
| Specific heat capacity | 479 | J/kg·K |
| Coefficient of thermal expansion (25–100 °C) | 14.0 | µm/m·°C |
| Magnetic permeability (200 Oe) | 1.001 | Essentially non-magnetic |
| Optimum service range | 840–1150 | °C |
Limiting composition per ASTM A240 (UNS S35045, wrought).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Iron | Fe | Balance | — | Base element |
| Nickel | Ni | 32.0 | 37.0 | Higher than 800H/HT; carburisation + structural stability |
| Chromium | Cr | 25.0 | 29.0 | Higher than 800H/HT; oxidation + sulfidation resistance |
| Carbon | C | 0.06 | 0.10 | Creep / stress-rupture strength |
| Aluminium | Al | 0.15 | 0.60 | High-temperature stability |
| Titanium | Ti | 0.15 | 0.60 | High-temperature stability |
| Manganese | Mn | — | 1.50 | Deoxidiser |
| Copper | Cu | — | 0.75 | Residual |
| Silicon | Si | — | 1.0 | Deoxidiser |
| Sulphur | S | — | 0.015 | Residual impurity |
Nominal room-temperature properties, solution-annealed (composites for various product forms; not for specification purposes).
| Form / Condition | Tensile strength | Yield strength (0.2%) | Elongation |
|---|---|---|---|
| Tubing, cold-drawn + solution-annealed | 586–627 MPa | 275–310 MPa | 45–50 % |
| Plate, hot-rolled + solution-annealed | 572–607 MPa | 275–296 MPa | 43–47 % |
| Sheet, cold-rolled + solution-annealed | 552–621 MPa | 275–331 MPa | 40–45 % |
| Rod, hot-finished + solution-annealed | 572–607 MPa | 207–255 MPa | 45–50 % |
The alloy has excellent stress-rupture strength at elevated temperature. Note: solid-state precipitation can occur between 590 °C and 815 °C on long exposure, reducing ductility/impact strength — solution annealing restores ductility. Values are typical; confirm against the mill test certificate.
| Environment | Performance | Notes |
|---|---|---|
| Carburisation | Outstanding | Key strength; superior to N08810 across a range of oxygen potentials |
| Cyclic oxidation | Outstanding | Excellent for thermal-cycling processing service |
| Static oxidation | Excellent | Protective scale to ~1100 °C |
| Sulfidation | Excellent | Outperforms N08810 |
| Creep / stress-rupture | Outstanding | Higher than 800H / 800HT |
| Chloride stress-corrosion cracking | Good | Like other 800-series alloys |
| Intergranular (sensitised) | Caution | Can sensitise at 540–760 °C; solution anneal to restore |
An austenitic solid-solution alloy; not age-hardenable. Solution annealing is used to develop properties and to restore ductility after high-temperature exposure.
Solution Anneal Temperature: ~1177 °C (2150 °F), e.g. 15 min, water quench Purpose: dissolves precipitates, restores ductility and corrosion resistance, develops grain structure for creep-rupture strength.
Caution — intermediate-temperature exposure: solid-state precipitation between 590–815 °C on long exposure reduces ductility; re-solution-anneal before repair or deformation after such service.
Good weldability, the same as alloy 800H. It should be joined using welding products with comparably high creep-rupture strength and high-temperature corrosion resistance.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / GMAW | Excellent | INCONEL Filler Metal 617 (general high-temperature service) |
| SMAW / stick | Good | INCONEL Welding Electrode 117 |
| Sulfidation-environment service | — | INCONEL Electrode 152 / Filler Metal 52 |
Use welding products with comparably high creep-rupture strength and high-temperature corrosion resistance.
Machining: readily machined by standard methods (similar to other 800-series alloys); the alloy work-hardens during machining.
Forming Processes
| Process | Notes |
|---|---|
| Hot forming | 870–1200 °C; heavy forging 1010–1200 °C; avoid 650–870 °C (cracking risk) |
| Cold forming | Readily cold-formed; moderate-to-high work-hardening rate |
| Solution anneal | ~1177 °C to restore structure after heavy cold work |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Ethylene production | ID-finned pyrolysis (cracker) tubing for high-severity furnaces | Carburisation resistance + creep-rupture strength |
| Petrochemical | Furnace tubing, pigtails, headers, process piping | High-temperature corrosion resistance |
| Chemical processing | Heat exchangers, thermal-processing hardware | Oxidation + sulfidation resistance |
| Thermal processing | Furnace components, radiant tubes | Cyclic-oxidation + carburisation resistance |
| Power / energy | High-temperature structural components | Stress-rupture strength to ~900 °C (ASME) |
| Product Form | ASTM Standard | ASME Code |
|---|---|---|
| Plate, sheet and strip | ASTM A240 / A480 | ASME Code Case 2304 |
| Seamless pipe and tubing | ASTM A213 | ASME SA-213 |
| Welded tubing | ASTM A249 | ASME SA-249 |
| Forgings | ASTM A182 | ASME SA-182 |
| ID-finned tubing | Special Metals proprietary | — |
| Welding consumables | INCONEL Electrode 117 · INCONEL Filler 617 (general); 152 / 52 (sulfidation) | — |
ASME Boiler and Pressure Vessel Code Section VIII Div. 1 (Code Case 2304) for service to 900 °C. Designation UNS S35045.
| Alloy | Ni % | Cr % | Other | Best Used For |
|---|---|---|---|---|
| Alloy 803 | 32–37 | 25–29 | C 0.06–0.10 | Ethylene cracker tubing; carburisation + creep to 1150°C |
| Alloy 800H | 30–35 | 19–23 | C 0.05–0.10 | High creep 593–980°C |
| Alloy 800HT | 30–35 | 19–23 | Al+Ti 0.85–1.20 | Highest 800-series creep |
| Alloy 600 | ≥72 | 14–17 | Ni-base | Higher Ni; carburisation to 1095°C |
| Alloy 330 | 34–37 | 18–20 | Si 1.0–1.5 | Carburisation + thermal shock to 1148°C |
021-33556635
13371897780
651280525@qq.com
No. 600, Si Chuang Road, Songjiang District, Shanghai
