Weld issue 304H flange to 304L pipe
Weld issue 304H flange to 304L pipe
(OP)
Appreciate it if anybody could comment on this below:
300# SO 304H flange welded to 304L pipe by filler material of 308H, cracks observed ai weld joint after temperature cycles 1250F. Can 304H be welded to 304L? is 308H a right filler material?
Thanks,
300# SO 304H flange welded to 304L pipe by filler material of 308H, cracks observed ai weld joint after temperature cycles 1250F. Can 304H be welded to 304L? is 308H a right filler material?
Thanks,





RE: Weld issue 304H flange to 304L pipe
Yes, 308 is the correct filler metal for this weld joint. What kind of cracks are you seeing visually? Orientation of the cracks relative to the weld? Are the cracks in the weld deposit itself or other location near the weld? Are there one or more cracks?
RE: Weld issue 304H flange to 304L pipe
RE: Weld issue 304H flange to 304L pipe
This is a classical hot crack from welding based on your attached photo. Back grind till sound metal and re-weld using 308 filler metal. I would perform a Liquid Penetrant examination after weld repair.
RE: Weld issue 304H flange to 304L pipe
If you think education is expensive, try Ignorance.
- Andy McIntyre
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RE: Weld issue 304H flange to 304L pipe
Weld repair as I mentioned above should work.
RE: Weld issue 304H flange to 304L pipe
It makes wonder about the heat input, it may be too high.
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Plymouth Tube
RE: Weld issue 304H flange to 304L pipe
That being said, there isn't anything inherently wrong with welding 304L to 304H with 308H. There is probably some other problem at work here.
RE: Weld issue 304H flange to 304L pipe
Good advice regarding sample removal. I think your statement regarding cracking from an undersized fillet has merit if a post weld NDT was indeed performed to ensure there were no cracks prior to service. There was no mention of any NDT that was performed prior to service.
I have seen hot cracking that actually opened first time in service as a result of subsurface hot tears breaking through to the fillet weld face due to poor weld joint geometry and shortly after solidification of weld metal due to lower than normal ferrite content in the weld metal.
RE: Weld issue 304H flange to 304L pipe
Thanks again.
RE: Weld issue 304H flange to 304L pipe
Go to the web site below and download this paper. It is an excellent source for high temperature properties. You can ballpark UTS and YS at temperature from the list of austenitic stainless steel grades.
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