800H
Alloy 800H is a high‑performance nickel‑iron‑chromium alloy engineered for exceptional strength and stability in high‑temperature environments. Designed to resist oxidation, carburization, and other forms of high‑temperature degradation, Alloy 800H delivers reliable performance in applications where long‑term exposure to elevated temperatures is expected.
With a nickel content of approximately 32%, Alloy 800H offers excellent resistance to chloride‑induced stress‑corrosion cracking and outstanding stability against sigma‑phase embrittlement, even during extended service. Its balanced chemistry provides strong overall corrosion resistance across a wide range of industrial environments.
In the solution‑annealed condition, Alloy 800H exhibits superior creep strength, stress‑rupture resistance, and metallurgical stability, making it a preferred material for components exposed to temperatures typically between 1100°F and 1800°F. These characteristics make Alloy 800H a dependable choice for heat‑treating equipment, petrochemical processing, industrial furnaces, and other severe‑service applications where both durability and resistance to thermal degradation are essential.
- Inventory & Specs
- Chemical Composition
- Physical Properties
- Mechanical Properties
- Datasheet
- Additional Info
- FAQs
Inventory Size Ranges for 800H
| Type | Thickness | AMS Standards | ASTM | ASME | Get a Quote |
|---|---|---|---|---|---|
| Coil | 0.040" & 0.063" | AMS 5871 | ASTM B 409 | ASME SB 409 | Get a Quote |
| Sheet | 0.040" & 0.063" | AMS 5871 | ASTM B 409 | ASME SB 409 | Get a Quote |
Characteristics of 800H
Alloy 800H is a controlled‑carbon, solution‑annealed nickel‑iron‑chromium alloy engineered for long‑term high‑temperature service, offering enhanced creep strength, stress‑rupture resistance, and excellent metallurgical stability in applications typically ranging from 1100°F to 1800°F. Its chemistry provides strong resistance to oxidation, carburization, and general corrosion, making it well‑suited for demanding environments such as petrochemical reforming, industrial furnaces, and power‑generation systems.
Working with 800H
Alloy 800H is readily weldable using most standard processes when in the solution‑annealed condition, offering good ductility and resistance to weld‑related cracking. During machining, the alloy work hardens quickly and performs best with low cutting speeds, rigid tooling, and continuous tool engagement, along with appropriate coolants and carbide tooling to maintain tool life, surface finish, and dimensional stability.
Other industry standards we comply with:
Common Trade Names
- ATI 800 (™ Allegheny Technologies)
- ATI 800H (™ Allegheny Technologies)
- ATI 800AT (™ Allegheny Technologies)
Industry Applications for 800H
- Heat Exchanger
- Dampers
- Pressure Vessels
- Reforming Components
- Industrial Heating
Chemical Composition
| Element | Min | Max | |
|---|---|---|---|
| C | Carbon | - | 0.08 |
| Mn | Manganese | - | 1.0 |
| P | Phosphorus | - | 0.02 |
| S | Sulfur | - | 0.01 |
| Si | Silicon | - | 0.35 |
| Cr | Chromium | - | 21.0 |
| Ni | Nickel | - | 32.0 |
| Ti | Titanium | - | 0.40 |
| Al | Aluminum | - | 0.40 |
| Cu | Copper | - | 0.30 |
Physical Properties
| Property | Value |
|---|---|
| Density | 0.29 lb/in3 |
| Magnetic Permeability | < 1.02 |
| Specific Heat | 0.12 Btu/lb°F |
| Electrical Resistivity | 99 microhm-cm at 70°F (21°C) |
| Temperature, °F | 70-200 | 70-1000 | 70-1200 | 70-1400 |
|---|---|---|---|---|
| in/in°F x 10-6 | 7.9 | 9.4 | 9.6 | 9.9 |
| Temperature, °F | 70 | 70-800 | 70-1800 |
|---|---|---|---|
| Btu-ft/ft2 -hr-°F | 6.7 | 10.6 | 17.8 |
| Temperature, °F | 1700 | 1800 | 1900 | 2000 | 2100 |
|---|---|---|---|---|---|
| Sample Weight Gain (mg/cm2) | 0.77 | 1.8 | 2.09 | 2.1 | 5.06 |
Mechanical Properties
| Temperature, °F | 70 | 1000 | 1200 | 1400 | 1500 |
|---|---|---|---|---|---|
| 0.2% Yield Strength, ksi | 43 | 31.7 | 29 | 22.6 | 14.2 |
| Ultimate Tensile Strength, ksi | 87.7 | 72 | 54 | 32.1 | 24.8 |
| Elongation | 44% | 39% | 56% | 85% | 91% |
Datasheet
Additional Info
A Brief History of 800H
Alloy 800H—part of the Alloy 800 family and known under designations UNS N08810 or W.Nr. 1.4958—was developed as an advanced, high‑temperature nickel‑iron‑chromium alloy for industrial environments where standard stainless steels could not withstand long‑term thermal exposure. Introduced in the mid‑20th century, Alloy 800H was engineered to provide elevated levels of creep strength, oxidation resistance, and structural stability in continuous high‑temperature service, particularly in furnace systems, petrochemical reformers, and power‑generation equipment. Its controlled‑carbon chemistry and solution‑annealed structure give it the metallurgical integrity needed for demanding thermal cycles.
How 800H Was Developed
Alloy 800H evolved from the original Alloy 800 formulation, which was designed to combine the corrosion resistance of nickel with the high‑temperature stability of chromium and iron. However, engineers recognized the need for improved long‑term strength in applications operating above 1100°F (593°C). By tightening the carbon range and optimizing the grain size through precise solution‑annealing practices, developers significantly increased the alloy’s creep resistance, stress‑rupture strength, and resistance to metallurgical degradation during prolonged thermal exposure. This refinement resulted in Alloy 800H—a material capable of sustaining mechanical integrity in severe, continuous‑duty high‑temperature environments.
Early Applications of 800H
With industrial demand increasing for alloys that could withstand high temperatures over long durations, Alloy 800H quickly became essential in energy, petrochemical, and thermal processing markets. Early applications included:
- Ethylene furnace tubes and transfer piping
- Petrochemical reformer components
- Superheater and reheater tubing
- Thermal processing trays, fixtures, and structural supports
- High‑temperature heat‑exchanger units
Its ability to maintain strength, resist oxidation, and avoid embrittlement under cyclic and continuous heating made Alloy 800H a preferred choice for equipment requiring exceptional reliability.
How 800H Is Used Today
Today, Alloy 800H remains a core high‑temperature alloy across industries that rely on materials capable of maintaining stability and mechanical performance under extreme thermal loads. Its strong resistance to oxidation, carburization, and general corrosion, combined with its enhanced creep and stress‑rupture properties, make it a top choice for power generation, petrochemical and refining, heat treating and industrial furnaces, and chemical processing.
Your Trusted Supplier for 800H
United Performance Metals supplies Alloy 800H in a full range of product forms with precision processing and quick‑turn availability. With deep experience supporting customers in the petrochemical, energy, heat‑treating, and high‑temperature manufacturing markets, UPM delivers Alloy 800H cut to your exact specifications through our world‑class FIRSTCUT+® processing services. Our knowledgeable team helps ensure you receive reliable, high‑performance material backed by consistent quality and dependable supply‑chain solutions.
Contact our team today to learn how Alloy 800H can enhance performance and reliability in your next high‑temperature application.