Hastelloy B-2

Aurico Alloys LLP supplies Hastelloy B-2 as sheet, plate, foil and round bar, from Mumbai, India, with EN 10204 3.1 mill test certificates.

Hastelloy® B-2 (UNS N10665, W.Nr. 2.4617) is a nickel–molybdenum alloy — molybdenum 26-30% with chromium held below 1% — built for hydrochloric acid at all concentrations. The near-absence of chromium is the point rather than an omission: it is a reducing-acid alloy, and it has no useful resistance in oxidising conditions.

Key Properties

Molybdenum 26-30% with chromium capped at 1.0% and iron at 2.0%.
Hydrochloric acid at every concentration and temperature, and sulphuric and phosphoric acid besides.
No oxidising resistance. Ferric and cupric ions attack it; where the service is mixed or not fully known, the C series is the family to quote.
Hastelloy B-3 is the thermally stable successor, with the same molybdenum content and controlled chromium and iron.

Applications

Hydrochloric acid reactors, piping and vessels
Acetic acid and acetic anhydride plant
Hydrogenation and alkylation equipment
Sulphuric and phosphoric acid handling

B-2 is a hydrochloric acid alloy only while the acid stays free of oxidising species: ferric ions, cupric ions and dissolved air all raise its corrosion rate. Why, and which grades take over when they are present, is set out in our acid and alkali service guide.

Available Forms

Equivalent Grades & Standards

Equivalent designations and physical constants for Hastelloy B-2
Property	Value
UNS number	N10665
Werkstoff / EN number	2.4617
EN designation	NiMo28
Density	9.22 g/cm³

Identifiers and physical constants for Hastelloy B-2. A dash means no such designation is published for this grade.

Specifications by Product Form

Hastelloy B-2 (N10665) is supplied to a different standard in each form. Quote the one that matches the product you are ordering.

Product form	Specification
Plate, sheet and strip	ASTM B333
Rod and bar	ASTM B335
Pipe and tube	ASTM B619 / B622
Fittings	ASTM B366