Incoloy 800, 800H, and 800HT are all iron-nickel-chromium alloys. Their core differences lie in the controlled content of carbon (C), aluminum (Al), and titanium (Ti), which directly determines their high-temperature performance.
Incoloy 800, 800H, and 800HT material supplier
HT PIPE is a well-known stockist and exporter. We are a Incoloy 800, 800H, and 800HT material supplier with 15+ export experience. We not only provide pipes, plate, round bars, but also pipe fittings, flanges, etc. Contact us for more information and prices for free.
Incoloy N08800, N08810, and N08811 chemical composition
| Grade | UNS | C≤ | Mn≤ | Si≤ | S≤ | Cu≤ | Fe(min) | Ni | Cr | Al | Ti |
| Incoloy 800 | N08800 | 0.1 | 1.5 | 1 | 0.015 | 0.75 | 39.5 | 30.0-35.0 | 19.0-23.0 | 0.15-0.60 | 0.15-0.60 |
| Incoloy 800H | N08810 | 0.05-0.10 | 1.5 | 1 | 0.015 | 0.75 | 39.5 | 30.0-35.0 | 19.0-23.0 | 0.15-0.60 | 0.15-0.60 |
| Incoloy 800HT | N08811 | 0.06-0.10 | 1.5 | 1 | 0.015 | 0.75 | 39.5 | 30.0-35.0 | 19.0-23.0 | 0.85-1.20 | 0.25-0.60 |
Incoloy 800, 800H, and 800HT Mechanical and Physical Properties
The three alloys have slightly different room-temperature tensile strength and yield strength, but their creep and stress-rupture properties at high temperatures are key differentiators.
- Incoloy 800 maintains good toughness for extended periods below 700°C.
- Incoloy 800H, due to its controlled carbon content and grain size, exhibits improved creep resistance and stress-rupture properties above 600°C.
- Incoloy 800HT, by increasing its Al and Ti content, achieves excellent yield strength and optimal creep strength above 700°C. For example, at 900°C/10,000 hours, the creep-rupture strength of 800HT is approximately 15-20% higher than that of 800H.
Incoloy 800, 800H, and 800HT Heat and Corrosion Resistance
Oxidation Resistance: The maximum continuous operating temperature of Incoloy 800/800H in oxidizing environments is approximately 900°C, while 800HT, due to its higher aluminum and titanium content, can reach 950°C.
Carburization Resistance: The high nickel content (Ni ≥ 30%) effectively inhibits carbon permeation in these alloys, making them suitable for environments prone to carburization, such as ethylene cracking furnaces.
Corrosion Resistance: They offer good corrosion resistance to oxidizing acids such as nitric acid and phosphoric acid, but are less resistant to reducing acids such as hydrochloric acid and hydrofluoric acid. The high nickel content also provides good resistance to chloride stress corrosion cracking.
Incoloy 800, 800H, and 800HT Processing and Welding
Heat Treatment: 800H and 800HT require solution treatment (typically at 1100-1170°C) and rapid cooling to achieve the desired coarse-grained structure. 800HT requires stricter heat treatment temperature control (±10°C) to ensure uniform precipitation of Al/Ti carbides.
Welding: All three alloys have excellent weldability and can be welded using methods such as TIG welding and submerged arc welding. ERNiCr-3 welding consumables are recommended. Solution annealing is recommended after welding to relieve welding stress and restore corrosion resistance.
Incoloy 800, 800H, and 800HT Selection Guide
Incoloy 800: Suitable for general high-temperature corrosion-resistant environments below 700°C where creep resistance is not a critical requirement, such as in some heating elements and pressure vessels.
Incoloy 800H: Suitable for applications in the 600-900°C range requiring higher creep strength and stress-rupture resistance, such as high-temperature reactors and high-temperature pipelines in the petrochemical industry.
Incoloy 800HT: It is suitable for ultra-high temperature and long-term pressure conditions exceeding 800°C, especially above 700°C, such as ethylene cracking furnace tubes, aerospace engine components, and other environments with extremely high creep performance requirements.
Typical B2B Industrial Applications
Ethylene Furnace Crackers: Radiant tubes, piping components, and fittings handling high-temperature hydrocarbon cracking.
Power Generation Plants: Steam superheater tubing, heat exchangers, and high-pressure coal gasification system components.
Industrial Thermal Processing: Forged retorts, muffle furnaces, radiant heaters, and continuous annealing fixtures working above 650°C.
Chemical Processing Equipment: Production components handling concentrated nitric acid, organic acids, and hot alkaline environments.
Complete Incoloy 800 / 800H / 800HT Product Line from HT PIPE
We support complete project procurement schedules by manufacturing and distributing high-performance alloys across all layout formats:
Seamless & Welded Piping: Fully certified to ASTM B407 / ASME SB407 and ASTM B514, available in custom wall schedules.
Heavy Industrial Plates: Sized to ASTM B409 / ASME SB409 specifications for pressure vessels and furnace shells.
Forged Components & Flanges: Weld Necks, Slip-ons, and Blind flanges machined to ASME B16.5 parameters.
Butt-Weld Fittings: Elbows, tees, and reducers constructed to match high-temperature pipeline integrity standards.
