Materials / Superalloy

Hastelloy B-2

UNS
N10665
W.Nr
2.4617
EN
NiMo28

A nickel-molybdenum alloy built for hydrochloric acid and other strongly reducing conditions, with chromium deliberately kept low.

Composition

Chemical composition limits, per cent by weight
ElementMinMax
Ni bal
Mo 26.0 30.0
Fe 2.0
Cr 1.0
Co 1.0
C 0.02

Per cent by weight, to the governing standard.

Nominal composition
  • Ni72.0
  • Mo28.0

Per cent by weight, at the midpoint of each specified window. Elements given only as a maximum have no midpoint to take, so they sit inside the balance rather than being estimated; trace elements below 0.5 % are not shown. Indicative only; the composition table above and the governing standard are what define the limits.

Mechanical

Tensile strength, min
760 MPa
Yield strength (0.2%), min
350 MPa
Elongation, min
40 %
Condition
Solution annealed

Standards by form

Governing standard for each product form
Plate, sheet & strip ASTM B333
Pipe & tube ASTM B622
Bar & rod ASTM B335

Where it is specified

  • Hydrochloric acid at all concentrations and temperatures
  • Sulphuric, acetic and phosphoric acid in reducing conditions
  • Not for oxidising service or ferric and cupric contamination

The weld zone is where B-2 gives way, not the plate

B-2 is prone to intermetallic precipitation in the heat-affected zone, so as-welded performance depends entirely on the solution anneal being right. Iron or chromium above the ceilings compromises the reducing-acid resistance the alloy exists for.

What we specify and check

  • PMI reading Mo against the 26.0–30.0 % window
  • Iron and chromium verified against their maximums
  • Solution anneal records demanded
  • Corrosion testing where the service is severe

We commission an accredited independent laboratory to test the heat before the material leaves China. You will receive that report unedited, whether it passes or not.

Request Hastelloy B-2

Tell us the form, dimensions and service conditions. We reply with availability, indicative landed price, lead time and the test regime we would specify for your application.

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