Hi Amol,
Please seethe requirements of UHT-79(Sec-VIII, DIV-1) for HT after forming.You may perform PWHT on completion. However there's no harm,( in fact a good engineering practice) to perform intermediate HT after forming. SA-517 (all grades) are not very fabrication friendly material. Hence some extra caution would be always good for follow.
Thanks.
Pradip Goswami, P.Eng,IWE
Welding & Metallurgical Specialist
Ontario, Canada
UHT-79 FORMING SHELL SECTIONS AND HEADS
(a) The selected thickness of material shall be such that the forming processes will not reduce the thickness of the material at any point below the minimum value required by the rules.
(1)
Pieces that are formed after heat treatment at a temperature lower than the final tempering shall be heat treated in accordance with Table UHT-56 when the extreme fiber elongation from forming exceeds 5%as determined by the formulas in UCS-79(d).(2)
Pieces that are formed at temperatures equal to or higher than the original tempering shall be reheat treated in accordance with the applicable material specification,either before or after welding into the vessel.From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of amol gengaje
Sent: Thursday, January 01, 2015 11:26 PM
To: materials-welding@googlegroups.com
Subject: [MW:22665] SA 517 Gr F - forming
we have to make a sphere from crown petal construction.Material SA 517 Gr F. UTS 790-820MPa. cold forming will be done
whether this will require intermediate heat treatment to avoid formation of cracking?
If so when/at which stage of forming it has to be carried out?
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