SA 671 normalize pipe
SA 671 normalize pipe
(OP)
we have a section of 40" dia 1/2" wall pipe 20 ft lg fabricated from SA516-65 that the code specified was to be normalized. Our engineer wanted it heated to 1550F. The pipe is now egg shape and distorted so it looks like we are going to built it agian. Is anyone familiar with this process and is there a way to support the pipe so that it holds it's shape in the furnace. Can we heat it again to try to get it back to shape? We braced it at both ends but the centre caved in.





RE: SA 671 normalize pipe
Regards,
Mike
RE: SA 671 normalize pipe
Chalk it up to a learning experience. Never heat treat something unless you have run calculations that show the support requirements. Make sure to include not just elevated temperature yield stress reduction, but short-term creep as well. Then, follow SnTMan's advice, and start again with normalized plate.
RE: SA 671 normalize pipe
RE: SA 671 normalize pipe
RE: SA 671 normalize pipe
TGS4- We are only a fabricator not a stress reliever. Is there a program or method to calculate the stiffeners required. I asked the stress reliever if we fabricate it over could the supply recomended support and they indicated they did not know how to support.
RE: SA 671 normalize pipe
If your stress-relief/heat-treat company can't do the calculations, then I suggest that you find one that can, or one that can hook you up with a consultant who can, or find a consultant who can on your own.
RE: SA 671 normalize pipe
Searches of the internet have not turned up any supplier willing to provide the type of informaiton that you indicate. Do you know of any company able to supply this type of informaiton?
RE: SA 671 normalize pipe
If you intend to normalize after long seam welding to eliminate the weld heat affected zone, you need to manufacture internal ribs that will be inserted into the pipe to act as bracing during the normalizing (1600 deg F) heat treatment OR work with smaller pipe spool lengths with bracing and then butt weld them together and perform a subcritical PWHT.