Welding Procedure for Incoloy 825
1. Preparation:
Clean the base material to remove any contaminants, oil, grease, or oxides.
Preheat is generally not required, but can be applied (100–150°C) for thicker sections to reduce thermal stress.
2. Welding Methods:
TIG (GTAW) and MIG (GMAW) are commonly used for Incoloy 825.
Stick welding (SMAW) with compatible electrodes is also possible.
3. Filler Material:
Use matching filler metals such as ERNiCrMo-3 or equivalent with similar chemical composition to Incoloy 825.
Filler wires or rods should match the base metal to ensure corrosion resistance and mechanical properties.
4. Shielding Gas:
Use argon or argon/helium mixtures to protect the weld pool from oxidation.
5. Interpass Temperature:
Keep below 300°C to avoid carbide precipitation and intergranular corrosion.
6. Post-Weld Treatment:
Typically, Incoloy 825 does not require post-weld heat treatment (PWHT).
Stress relief can be done if necessary, but usually avoided to maintain corrosion resistance.
7. Welding Parameters:
Use low heat input to reduce distortion and maintain weld quality.
Control welding speed and amperage according to thickness and joint design.
