Welding Nickel Alloys

Nickel and nickel alloys

Weldability of materials

Nickel and nickel alloys are chosen because these alloys are perfect for use in the heat treating industry.

  • corrosion resistance
  • heat resistance and high temperature properties
  • low temperature properties

Weldability

There are many welding consumables in various forms including: coated electrodes, MIG & TIG wire. Most nickel alloys can be fusion welded using gas shielded processes like TIG or MIG. of the flux processes, MMA is frequently used but the SAW process is restricted to solid solution alloys and is less widely used. For gas turbine industry, we recommend single flag-tagged, double flag-tagged, layer wound spool or colour coded products and for critical welding procedures, we should go for E-Grade quality.

Filler alloys

Filler composition normally matches the parent metal. Most fillers contain a small mount of titanium, aluminium and/or niobium to minimise the risk of porosity and cracking. If you’re not sure which welding consumables to use, then youc can select alloys are given below in the table:

Table 1: Filler selection for nickel alloys

Parent Alloy Filler designations Description
Alloy BS EN ISO 18274 AWS A5.14 Trade names
Pure nickel        
Nickel 200 Ni 2061 ERNi-1 Nickel 61 Matching filler metal normally contains 3%Ti
Nickel Copper        
Alloy 400 Ni 4060 ERNiCu-7 Monel 60 Matching filler metal contains additions of Mn, Ti and Al
Nickel Chromium        
Brightray S Ni 6076 NC 80/20 Ni-Cr and Ni-Cr-Fe filler metals may be used
Nimonic 75 Ni 6076 NC 80/20
Nickel-Chromium-Iron        
Alloy 800 Ni 6625 ERNiCrMo-3 Inconel 625
Thermanit 21/33
Welded with Ni-Cr-X alloys, but more nearly matching consumables are available which contain higher C and also Nb
Alloy 600 Ni 6082 ERNiCr-3 Inconel 82 Matching filler metal contains Nb addition
Alloy 718 Ni 7718 ERNiFeCr-2 Inconel 718 Matching filler metal is normally used but Alloy 625 is an alternative consumable , if postweld heat treatment is not applied
Nickel-Chromium-Molybdenum        
Alloy 625 Ni 6625 ERNiCrMo-3 Inconel 625 Filler metal is also used widely for cladding and dissimilar welds
Hastelloy C-22 Ni 6022 ERNiCrMo-10 Hastelloy C-22  
Nickel-Molybdenum        
Hastelloy B-2 Ni 1066 ERNiMo-7 Hastelloy B-2 Corrosion resistant alloys require matching fillers

Common imperfections found on welding are:

  • porosity
  • oxide inclusions and lack of inter-run fusion
  • weld metal solidification cracking
  • microfissuring
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