What is 1.4501 Stainless Steel?

1.4501 stainless steel, widely known by its trade name Zeron 100 (and also as UNS S32760 or F55), is a super duplex stainless steel enhanced with tungsten and copper. It represents the highest echelon of duplex alloys, offering an extraordinary combination of immense strength, exceptional corrosion resistance-especially against pitting and stress corrosion cracking-and improved weldability, making it the ultimate choice for the most aggressive offshore, chemical, and subsea environments.

 

This premium super duplex grade is defined under key international standards.

Standard	Equivalent Grade
EN (Europe)	1.4501
ASTM/AISI (USA)	F55, UNS S32760 (Zeron 100)
Common Name	Zeron 100

Its superior performance is achieved through a high, balanced alloy content including tungsten and copper.

Element	C	Si	Mn	P	S	Cr	Ni	Mo	N	W	Cu
Content (%)	≤ 0.03	≤ 1.0	≤ 1.0	≤ 0.03	≤ 0.01	24.0 - 26.0	6.0 - 8.0	3.0 - 4.0	0.20 - 0.30	0.50 - 1.00	0.50 - 1.00

It provides extreme strength and toughness, even in aggressive conditions.

Property	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HB)	Impact (J)
Typical Value	≥ 550 MPa	750 - 1000 MPa	≥ 25%	≤ 300	≥ 45 (-40°C)

 

Key Characteristics and Applications of 1.4501 / Zeron 100

Unmatched Corrosion Resistance: Possesses an exceptionally high Pitting Resistance Equivalent Number (PREN > 40), offering best-in-class resistance to pitting, crevice corrosion, and stress corrosion cracking in hot, chloride-laden environments.

Extremely High Strength: Delivers yield strength approximately double that of standard austenitic steels, enabling significant weight and cost savings in pressure vessels and structural components.

Enhanced Weldability: The balanced composition, including tungsten and copper, promotes a stable microstructure in welds, making it more forgiving to weld than some other super duplex grades.

 

Primary Applications:

Subsea & Offshore: Christmas trees, manifolds, flowlines, and umbilicals in deepwater oil & gas production.

Chemical & Process: Reactors, columns, and heat exchangers handling aggressive mixtures of acids, chlorides, and other corrosive media.

Pollution Control: FGD scrubbers, absorber towers, and critical ductwork.

Pulp & Paper: High-pressure and high-temperature digesters.

 

How does Zeron 100 (1.4501) differ from Super Duplex 2507 (1.4410)?
While both are super duplex grades, Zeron 100 contains additional alloying elements-tungsten (W) and copper (Cu). Tungsten further enhances pitting and crevice corrosion resistance, particularly at elevated temperatures, and improves the stability of the microstructure during welding. Copper enhances resistance to reducing acids like sulfuric acid. This gives Zeron 100 a performance edge in the most complex and severe corrosive environments, especially those involving both chlorides and acids.

 

What makes welding Zeron 100 different from welding standard duplex steels?
Welding Zeron 100 follows similar principles (controlling heat input, using over-alloyed filler) but benefits from its enhanced composition. The tungsten content helps retard the formation of detrimental intermetallic phases in the heat-affected zone (HAZ), providing a wider "processing window" and reducing the risk of embrittlement. It still requires careful procedure qualification but is generally considered to have better weldability than other super duplex alloys of similar corrosion resistance.

 

Looking for a Reliable Supplier of 1.4501 / Zeron 100 Stainless Steel?
GNEE Steel supplies the premium super duplex grade Zeron 100 (1.4501/UNS S32760) for the most critical and corrosive applications. We provide plate, pipe, fittings, and bar with full traceability and comprehensive certifications. If you have any requirements, please feel free to contact us.