What are the core characteristics of EN 1.4762 stainless steel?

Apr 02, 2026

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1.4762 stainless steel, commonly known as 446 or UNS S44600, is a high-chromium ferritic stainless steel designed for exceptional resistance to high-temperature oxidation and sulfidation. With its elevated chromium content (23-27%), it offers superior scaling resistance at temperatures up to 1100°C, making it the material of choice for demanding high-temperature applications such as furnace components, burner parts, and heat treatment equipment where conventional stainless steels would rapidly degrade. Its ferritic structure provides good thermal conductivity and low thermal expansion, essential for thermal cycling applications.

Standard	Equivalent Grade
EN (Europe)	1.4762
ASTM/AISI (USA)	446, UNS S44600
Common Name	446

Element	C	Si	Mn	P	S	Cr	N
Content (%)	≤ 0.20	≤ 1.0	≤ 1.5	≤ 0.04	≤ 0.03	23.0 - 27.0	≤ 0.25

Property	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HB)
Typical Value (Room Temp)	≥ 275 MPa	450 - 600 MPa	≥ 20%	≤ 220

Exceptional High-Temperature Oxidation Resistance: The high chromium content (23-27%) provides outstanding resistance to scaling and oxidation in continuous service up to 1100°C (2010°F) and intermittent service up to 1050°C (1920°F).

Excellent Sulfidation Resistance: Superior resistance to sulfur-containing atmospheres makes it ideal for high-temperature applications in the presence of combustion gases and sulfur compounds.

Low Thermal Expansion: Ferritic structure provides lower thermal expansion than austenitic grades, reducing thermal stress in cyclic heating applications.

Good Thermal Conductivity: Higher thermal conductivity than austenitic stainless steels, beneficial for heat transfer applications.

Furnace Components: Radiant tubes, burner parts, retorts, muffles, and furnace linings.

Heat Treatment Equipment: Support grids, trays, baskets, and fixtures for heat treating operations.

Petrochemical Industry: Components in reformers, crackers, and high-temperature process equipment.

Power Generation: Superheater tubes, boiler components, and heat recovery systems.

Glass Industry: Glass handling equipment and kiln components.

Cement Industry: Preheater cyclones and ducting.

Waste Incineration: Combustion chambers and heat exchangers in high-sulfur environments.

446 offers superior oxidation resistance at higher temperatures compared to both 310S and 316L. While 310S is suitable up to about 1150°C, 446 provides excellent performance up to 1100°C with better resistance to sulfur-containing atmospheres. Compared to 316L, which is limited to about 800°C, 446 offers dramatically higher temperature capability. However, 446 is ferritic (magnetic) with lower toughness at room temperature and reduced weldability compared to austenitic grades. 446 is often chosen for applications where high-temperature oxidation and sulfidation resistance are paramount, and where the ferritic structure's thermal expansion characteristics are advantageous.

Welding 446 requires careful control due to its ferritic structure. Key considerations include:

Low heat input welding techniques are essential to minimize grain growth in the heat-affected zone

Preheating (200-300°C) is recommended to reduce thermal shock and prevent cracking

Austenitic filler metals (309L, 310L) are recommended for better weld ductility and to avoid embrittlement

Post-weld annealing at 760-820°C followed by slow cooling may be required to restore ductility

For critical applications, welding in the annealed condition is preferred

Thicker sections require careful procedure qualification to avoid cracking

While 446 offers exceptional high-temperature performance, it has several limitations:

Brittle at room temperature, particularly in thicker sections and in the as-welded condition

Poor weldability compared to austenitic grades, requiring careful procedure control

Limited toughness, especially at lower temperatures

Not suitable for cryogenic applications due to ductile-to-brittle transition

Can be susceptible to 475°C embrittlement after prolonged exposure in the 400-500°C range

Lower strength at room temperature compared to precipitation-hardening grades

GNEE Steel supplies premium high-temperature 446 (1.4762) stainless steel in plate, sheet, bar, and forging forms for demanding furnace and heat treatment applications. We provide full material certification (EN 10204 3.1) and processing support including cutting, forming, and welding guidance. If you have any requirements, please feel free to contact us.