Material Family

Nickel-Molybdenum Alloy (Low Iron, Low Carbon) Coil/Strip

The coiled form of the premier alloy for severe, non-oxidizing reducing acid service.

Common Forms & Tempers

Forms: Cold Rolled Coil (Strip), Annealed Pickled Coil.
Temper: Typically supplied in Annealed (Soft) temper for forming. Hard tempers are uncommon due to fabrication sensitivity.

The annealed condition is essential for forming and to maintain corrosion resistance.

Chemical Composition (Typical wt.%)

Ni: ≥ 69.0 (Balance)
Mo: 26.0 - 30.0
Fe: 2.0 max
Cr: 1.0 max
C: ≤ 0.010
Si: ≤ 0.08

Extremely High Molybdenum (Mo) provides resistance to reducing acids. Very Low Chromium (Cr) and Iron (Fe) are critical to prevent catastrophic attack by even trace oxidants.

Mechanical Properties (Annealed Coil, Room Temp)

Tensile Strength (Rm): 760 - 965 MPa
Yield Strength (Rp0.2): 350 - 550 MPa
Elongation (A): 40 - 60%

High strength and excellent ductility in the annealed condition, suitable for stamping and forming.

Coil Physical Specifications (Typical)

Thickness: 0.20mm - 2.5mm (0.008" - 0.100")
Width: 10mm - 600mm (0.4" - 24")
Coil I.D.: 300mm, 405mm, 508mm (12", 16", 20")
Coil Weight: 50kg - 1000kg

Supplied with controlled dimensions for fabrication, but thermal management during processing is critical.

Key Corrosion Resistance (and Limitation)

• Unparalleled resistance to hydrochloric acid (HCl) at all concentrations and temperatures up to the boiling point.• Excellent resistance to sulfuric (H₂SO₄), phosphoric (H₃PO₄), and acetic acids under strictly reducing, oxygen-free conditions.

•  CRITICAL LIMITATION: Very poor resistance to oxidizing agents (e.g., Fe³⁺, Cu²⁺ ions, HNO₃, oxygen, chlorine). Presence of even ppm-level oxidants can cause severe, rapid corrosion.

A specialist alloy with an extremely specific application window. Must be used in strictly oxygen-free, reducing environments.

Key Standards (Strip/Coil)

ASTM B333 / ASME SB-333 (Sheet, Strip, and Plate - Grade UNS N10665), DIN 2.4617

ASTM B333 is the primary material specification for coil (strip) products.

 Critical Fabrication Warning

Severe Thermal Sensitivity: Prolonged exposure in the 550-1050°C range (during slow cooling from annealing, welding, or brazing) can cause precipitation of brittle intermetallic phases (mu, P), drastically reducing ductility and corrosion resistance. Fabrication requires rapid cooling after any thermal cycle.

This is the major drawback of B-2. It makes welding and complex fabrication high-risk without extreme control.

Typical Coil Applications

• HCl Service: Gaskets, seals, bellows, and shrouds for dedicated hydrochloric acid production, pickling, and handling systems.
• Reducing Acid Process Components: Diaphragms for acid pumps, valve liners, heat exchanger plates for strictly controlled sulfuric/acetic acid processes.
• Specialty Chemical: Components for catalysts and intermediates production in oxygen-free environments.

Used almost exclusively for mass-produced parts in highly controlled, strictly reducing chemical processes.