NORMALIZING OF CLADDED DISH END AFTER COLD FORMING

[KDBT]

Hello all
i have clad plate of (40+5 mm) sa-516 gr 70 + sa-240 317 . We are giving that plate for dished end manufacturing , cold forming
My vendor say that he will do normalizing of cold form dish end at 910°C for 1 hr 10 min .
my question is what will happen to ss-317 plate if heated at 910°C . will this temperature will tear down the clad bonding also .
Is S.R is not enough 610°C for 1 hr 45 min . As per ASME code i am not bale to find any such data .

 

[SJones]

http://www.eng-tips.com/search.cfm?q=heat+treatment+of+clad&action=search

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[chicopee]

I can not answer your question but if you do a search of the National Board bulletins, there may be some useful information.

 

[r6155]

See SA-264

Regards
r6155

 

[pradipgoswami]

You may check post forming HT requirements in UCS-79.Dished heads will not require any post forming HT if the outer fibre elongation is below 5%.
For clad heads any post forming HT should avoid sensitization range 620+/- 20 Deg C. Hence normalizing is the best option as suggested by the vendor.
Point to Note:-Clad plates are usually normalized in the mill after roll-Cladding(Most common clad plate manufacturing technique).Hence additional normalizing after forming may alter the original mechanical properties. One should check with the mill for their opinion and as a bare minimum requirement a simulation HT coupon should be tested before normalizing the dished head.

C.S Clad vessels with 40 mm base metal thickness would call for PWHT after complete fabrication. Such PWHT may be performed as per the PWHT cycle(Temperature) of UCS-56 or UCS-56.1.
Irrespective of the PWHT or post forming HT adopted(as suggested above) an IGC conforming to ASTM A 262, Practice E, should be performed for clad restoration (SS 317)as a good engineering practice or if mandated by project.


Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299