Materials / Superalloy

Hastelloy B-3

UNS
N10675
W.Nr
2.4600
EN
NiMo29Cr

A modernised B-family alloy with markedly better thermal stability than B-2, resisting the intermetallic precipitation that limits the older grade.

Composition

Chemical composition limits, per cent by weight
ElementMinMax
Ni bal
Mo 27.0 32.0
Cr 1.0 3.0
Fe 1.0 3.0
Co 3.0
C 0.01

Per cent by weight, to the governing standard.

Nominal composition
  • Ni66.5
  • Mo29.5
  • Cr2.0
  • Fe2.0

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 and reducing service where B-2 fabrication risk is unacceptable
  • Far more tolerant of welding and thermal cycling than B-2
  • Still not for oxidising conditions

B-2 and B-3 both quote as "Hastelloy B" and are not equivalent

B-3 and B-2 both quote as "Hastelloy B", which is all it takes for the two to be interchanged. They are not equivalent: B-3's chromium and iron windows are what give it thermal stability, and B-2 supplied against a B-3 specification will crack where B-3 would not.

What we specify and check

  • PMI distinguishing the Cr 1.0–3.0 % and Fe 1.0–3.0 % windows from B-2
  • Carbon verified against the 0.01 % maximum
  • Written confirmation of the UNS number before the PO

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-3

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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