Nickel Alloy B3

Nickel alloy B3 is a nickel-molybdenum alloy. It is resistant to hydrochloric acid at all concentrations and temperatures. It is also resistant to a wide range of other acids including sulphuric, formic,  phosphoric and acetic acid. 
In addition, it has good resistance to stress corrosion cracking (SCC) when exposed to chloride containing solutions. 

Properties

B3, in common with most nickel alloys offers excellent corrosion resistance. B3 is particularly useful in chemical processes involving highly corrosive acids at temperatures that would normally produce rapid and catastrophic corrosion.

It is structurally stable, is ductile, easily formed and presents few problems when being welded - providing the piece is raised to a sufficient temperature - due to its excellent thermal stability. In general, it can be hot worked providing the temperature is held at 1230oC for long enough for the entire piece is raised to a temperature.

It can also be cold worked but is subject to hardening.

It is widely used in the chemical processing industry and for storage corrosive acids.

What are the main uses of Nickel Alloy B3?

Due to its thermal stability and corrosion resistance, it is typically used in:

  • Chemical processes
  • Vacuum furnaces
  • Mechanical components in reducing environments

What are its main benefits of B3?

Corrosion Resistance

The major benefit of B3 is its resistance to corrosion by a wide range of acids, particularly hydrochloric. Exposure to a 20% solution of hydrochloric acid at 10oC results in virtually no corrosion and even at 100oC the corrosion is less than 0.3mm/y.

In general, it has excellent resistance to pitting corrosion, and stress-corrosion cracking.

Heat resistance

Its stability when exposed to heat is excellent. One of the problems of the nickel-molybdenum alloys is the tendency to form Ni4Mo when heated to temperatures in the range 500oC to 900oC. This particular phase is extremely hard and has excellent yield strength, unfortunately, it is also extremely brittle. 

Chemical formulation of Alloy B3 has been carefully adjusted to ensure that it tends to form Ni3Mo which does not suffer from the same embrittlement problem.

The low carbon content (0.01% max) is such that it does not require annealing after welding.

What are the limitations B3?

B3 has poor corrosion resistance in oxidising environments. In particular, it is highly susceptible to corrosion in the presence of iron or copper salts.

This represents a potential problem if B3 components are used as part of a plant also employing stainless steel copper piping where even a small quantity of copper or iron in the presence of hydrochloric acid could result in rapid failure.

Chemical composition of B3

Ni

Mo

Cr

Fe

W

Mn

Co

Al

Ti

Si

C

Nb

V

Cu

Ta

Zr

65
min.

28.5

1.5

1.5

3
max.

3
max.

3
max.

0.5
max.

0.2
max.

0.1
max.

0.01
max.

0.2
max.

0.2
max. 

0.2
max. 

0.2
max. 

0.01
max. 

Detailed properties

Physical Properties

 

Metric

English

Density

9.2g/cc

0.332371 lb/in³

               

Mechanical Properties

Hardness, Brinell

341

341

Converted from Rockwell B hardness.

Hardness, Rockwell B

109

109

  

Tensile Strength, Ultimate

760 MPa

110229 psi

  

Tensile Strength, Yield

350 MPa

50763 psi

at 0.2% offset

Elongation at Break

58%

58 %

in 50 mm

Modulus of Elasticity

216 GPa

31328 ksi

 Room Temperature 

Electrical Properties

Electrical Resistivity

1.37 μohm.m

1.37 μohm.m

at 20°C ;1.43 μohm.m at 600°C 

Thermal Properties

25 -­100°C

10.6 μm/m.°C

  

from 0-100°C

25­ - 400°C

11.4 μm/m.°C

  

at 0-315°C (32-600°F)

25 - ­600°C

11.8 μm/m.°C

  

at 0-650°C

Specific Heat Capacity

382 J/kg.°C

  

from 0-100°C (32-212°F)

Thermal Conductivity

12.1 W/m.°C

  

at 0-100°C

Melting Point

1370 - ­1418°C

2500 - ­2585°F

  

Forms available

Forms Available

  • Tube
  • Pipe
  • Fittings
  • Flanges
  • Special Sections
  • Sheet
  • Plate
  • Flat Bar
  • Round Bar
  • Hollow Bar
  • Angles
  • i Beam
  • U Channel

Austenitic

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