A nickel-molybdenum grade, Alloy B-2 is extremely resistant to hydrochloric acid in a wide range of temperatures.

Alloy B-2 is a solid-solution strengthened nickel alloy which is normally used in extreme reducing conditions. Alloy B-2 also exhibits good resistance to hydrogen chloride, sulphuric acid and phosphoric acid.

  • UNS Number: UNS N10665
  • Werkstoff Number: 2.4617
  • ASTM: B333, B335, B564, B619, B622, B626, B366, B462, B775

Product availability

Round Bar

Chemical analysis



  • Pressure vessels and reactors
  • Agitators and mixers
  • Pumps and valves
  • Gaskets
  • Pipe work and pipe spools
  • Heat exchangers

About Alloy B-2

Alloy B-2 is a nickel-molybdenum alloy with significant resistance to reducing environments, such as hydrogen chloride gas and sulphuric, acetic and phosphoric acids. Hastelloy® B-2 provides resistance to pure sulphuric acid and a number of non-oxidising acids. The alloy should not be used in oxidising media or where oxidising contaminants are available in reducing media. Premature failure may occur if alloy B-2 is used where ferric iron, cupric ion and free chlorides are present.

With a high nickel content, Hastelloy® B-2 is immune to chloride-induced stress corrosion cracking.

Hastelloy® is the registered trademark of Haynes International.

  • Density: 9.22 g/cm³
  • Melting Range: 1332-1382°C
  • Specific Heat Capacity: 377 J/kg.°C
  • Electrical Resistivity: 1.37 µΩ.m

Mechanical & Physical Properties

Mechanical & Physical Properties21.1°C93.3°C204.4°C315.6°C426.7°C537.8°C648.9°C
Ultimate Tensile Strength /MPa894-849823806--
0.2% Yield Strength /MPa412-350328310--
Elongation %61-596060--
Coefficient of Thermal Expansion /µm/m°C-10.310.811.211.511.7-
Thermal Conductivity /kcal/(hr.m.°C) **9.5510.4911.5212.5613.7614.8816.08
Modulus of Elasticity / GPa217--202196189-
Proud members of the British Valve & Actuator AssociationProud members of the British Valve & Actuator Association