Geof
Mechanical
- Feb 2, 2001
- 59
We have a weld procedure for P45 to P45 material that has worked fine, but recently had an issue with 1-1/2" socket weld fittings made from cast CN7M.
Some of the castings developed pinhole leaks near the welds in the heat affected zone.
Hydrotest, air test, visual, and dye penetrant examinations prior to welding found a few issues, but nothing seemed to correlate to the crack development.
A welder with experience on these materials increased preheat to 150°F and issue the issue seems to have been resolved.
Not being a welding engineer, I wanted to find out:
- Is elevated preheat recommended for all P45 materials?
- Or for CN7M castings in particular?
Thanks.
Some of the castings developed pinhole leaks near the welds in the heat affected zone.
Hydrotest, air test, visual, and dye penetrant examinations prior to welding found a few issues, but nothing seemed to correlate to the crack development.
A welder with experience on these materials increased preheat to 150°F and issue the issue seems to have been resolved.
Not being a welding engineer, I wanted to find out:
- Is elevated preheat recommended for all P45 materials?
- Or for CN7M castings in particular?
Thanks.