Seamless stainless steel tubes in steel Alloy 800H

Seamless stainless steel tubes in steel Alloy 800H

What is Alloy 800H seamless stainless steel tube?

Alloy 800H (commercial name: Incoloy 800H) is a heat‑resistant nickel‑iron alloy with chromium, aluminium and titanium additions. In tube form it is supplied as seamless stainless steel tubes for demanding, high‑temperature and corrosive environments. Common material designations you may see are: European EN numbers 1.4876 / 1.4958 and the US designation UNS N08810.

Chemical makeup (typical ranges)

The chemical composition commonly quoted for Alloy 800H is:

• Nickel (Ni): 30.0–35.0%
• Chromium (Cr): 19.0–23.0%
• Carbon (C): 0.05–0.10% (the “H” denotes higher carbon for improved high‑temperature strength)
• Aluminium (Al): 0.15–0.60%
• Titanium (Ti): 0.15–0.60%
• Iron (Fe): balance (typically ~39.5% or higher)
• Small amounts of Mn, Cu, P, S within standard limits

Key properties and performance

Alloy 800H seamless tubes offer a combination of heat resistance, oxidation/carburisation resistance and good mechanical strength at elevated temperatures. Important features:

• Designed for stable mechanical properties at elevated temperatures-Alloy 800H is selected where creep and tensile strength at high temperature are required.
• Good resistance to oxidation and carburisation in many industrial atmospheres.
• Seamless construction gives improved pressure capability and uniformity compared with welded tubes-important for high‑temperature and high‑pressure systems.
• Weldable by standard methods; follow supplier recommendations for heat treatment or solution annealing for critical high‑temperature service.

Typical temperature range

Alloy 800H is intended for elevated temperature use. It maintains useful mechanical properties over a wide range; the exact allowable service temperature depends on application and design (creep considerations). For design and safety limits refer to relevant codes and supplier datasheets.

Where and how these tubes are used

Seamless Alloy 800H tubes are chosen wherever resistance to high temperature and corrosive atmospheres is needed. Typical applications and sectors include:

• Chemical and petrochemical plants: pipes, heat exchangers, reactors and process equipment where high temperature corrosion resistance is required.
• Power generation: boiler components, superheater/reheater tubes, heat exchangers and other high‑temperature plant items.
• Oil & gas: high‑temperature piping, components in refineries and processing units.
• Furnaces and heat‑treatment equipment: radiant tubes, muffles and sections exposed to carburising or oxidising atmospheres.
• Metallurgy and industrial ovens: parts and tubes operating at elevated temperatures.
• Specialist manufacturing and OEMs: components where long‑term strength at temperature is important (including some aerospace and industrial gas turbine ancillary parts).
• Maintenance, repair & small workshops: when replacement seamless tubes are required for high‑temperature service.

Benefits of seamless stainless steel tubes

Choosing seamless tubes in Alloy 800H gives several practical advantages:

• Uniform material properties around the circumference-no weld seam that could be a weak point under pressure or thermal cycling.
• Better performance in high‑pressure and high‑temperature applications.
• Smoother internal surface (depending on finish) favourable for flow and fouling control in heat exchangers and process lines.
• Available in a range of diameters and wall thicknesses suitable for pressure vessel and piping codes.

Standards, fabrication and specification notes

When specifying seamless Alloy 800H tubes for the UK market, include the material designation (for example Alloy 800H / UNS N08810 / EN 1.4876, 1.4958) and the required standard or code. Common practice is to reference EN or ASTM/ASME specifications for seamless tubes and pressure parts.

Fabrication notes:

• Alloy 800H is weldable by common processes (TIG, MIG, etc.); however, welding and post‑weld treatments should follow supplier and code guidance for high‑temperature service.
• For critical high‑temperature components, correct heat treatment (solution annealing and controlled cooling where required) is important to obtain specified mechanical properties.
• Surface cleaning, pickling and passivation after welding are recommended to restore corrosion resistance in some cases.

Who buys these tubes?

Typical buyers include plant engineers, procurement teams, OEMs, maintenance crews, fabricators and contractors working in:

• Chemicals and petrochemicals
• Power generation and boiler manufacturers
• Oil and gas and refinery maintenance
• Industrial furnace builders and heat‑treat shops
• Specialist fabricators and high‑temperature equipment manufacturers

Ordering and technical support

If you need seamless stainless steel tubes in Alloy 800H, specify the material designation, required dimensions (outside diameter, wall thickness, length), tolerance/finish and applicable standard (EN/ASTM/ASME). For critical applications ask for material certificates (e.g. EN 10204 3.1), heat treatment records and, if required, NDT or traceability documentation.

Contact us for datasheets, supply options and help selecting the right grade and tube dimensions for your UK project or industry application.