Hydrogen Induced HAZ Cracking:
Causes:
- Hardened HAZ coupled with the presence of hydrogen diffused from weld metal.
- Susceptibility increases with the increasing thickness of section especially in steels with high carbon equivalent composition.
- Can also occur in weld metal
- Increase welding heat beneficial
- Preheating sometimes necessary
- Control of moisture in consumables and cleanliness of weld prep desirable
