Inconel 625 Grade 1 cladding with sa516 gr 70

[Kunal A]

Hello Seniors,

I am new to this website. I am handling this project as Project Engineer, Working in a U stamp OEM. Have come across a situation.

Pressure Vessel:- SA 516 Gr 70 14mm & Inconel 625 3mm Cladding by Explosion bonding process.

My Design team has considered Grade 2(Solution anealed inconel plates, fittings, Pipes and forgings) which i am finding difficult to procure in given project time line. As i know grade 1 has better mechanical properties than grade 2 and only reason Grade 2 has been chosen is because of service temperature above 593 C as per ASTM B 444 & B 443.(Also in Astm 443/444 1.1.1.2 note has been given that "Hot-working or re annealing may change properties significantly, depending on working history and temperatures." is this given for only grade 2 or for both 1 and 2.

Our vessels have Service temperature not more than 60deg C. but There is PWHT at 610 C (35 min)and dish heads are normalized at 910 C (14 min). This pwht and Normalizing are crossing Grade 1 service temp.

As per standard practice what is advised? as this is my first cladded vessel.

Should i Go for Grade 1 or Grade 2 (Please provide any design reference for code reference if possible.

Kunal Ajgaonkar.

 

[metengr]

For this application, it would be Inconel cladding material, similar to Grade 1.

 

[pradipgoswami]

Please go though this document to get a comprehensive idea on how clad plates and various other cladded components are manufactured.
As I see out in your query there're some missing knowledge on how the clad components would get manufactured including the required PWHT.
It's FYI a lot clad fittings could be manufactured by "weld overlay" on solid carbon steel fittings, which is quite economical way provided such manufacturing facility exists. Vendors need to have excellent GTAW & GMAW facility dealing with Inconel 625 weld overlay. Many offshore equipment /fittings vendors are equipped with this. Also many such vendors are in Europe,geographically closer to your location. It's not mandatory that all clad fittings have to be solution annealed before supply.

Clad plates are long lead items , depending on the alloy involved they may be roll-clad or explosion clad. However clad fittings could always be manufactured through the route of weld overlay.

Thanks.

http://www.nipera.org/~/Media/Files/TechnicalLiterature/10064_EngineeringWithCladSteel2ndEd.pdfn

your query there are

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

 

[Kunal A]

Dear Pradip,

Thanks for your guidance.

Clad fittings are already arranged which will be overlayed by GTAW pulse hot wire process. Which are not of my difficulties.

In my vessels there are 70% nozzles of size 4'' and below, As per KOC spec 4'' and below need to be solid Inconel 625 not cladded. These need to be of Grade 2. Plus the Inconel plates also needed to be grade 2(Which will be explosion bonded to SA 516 Grade 60/70).

I was thinking of possibility to deviate material to grade 1 but was unsure that would the grade 1 nozzles and Inconel plate(3mm which will be explosion bonded to vessel) would withstand Normalizing at Dishend and PWHT after completion of full vessel.

As per KOC spec Explosion bonding or roll bonding is the only option for us overlay is not allowed for vessel(only allowed for nozzles 6'' and above)


Kunal Ajgaonkar.

 

[pradipgoswami]

Hi Kunal,

KOC is a reputed organization with good engineering specifications. Acceptance of the order definitely means fulfilling all contractual technical requirements. Any deviation will be subject to clients' acceptance.It's not advisable to form conclusive opinion/s on the basis of discussion in any open forum.

For example, extract from SB 444 specifies two grades of different heat-treated conditions for UNS N06625
Grade 1 (annealed)—Material is normally employed in service temperatures up to 1100°F (593°C).
Grade 2 (solution annealed)—Material is normally employed in service temperatures above 1100°F (593°C) when resistance to creep and rupture is required.
In 625 is always used in highly demanding environments, where corrosion is a serious criteria.Obviously grade 2 provides overall better properties than grade 1 for such environments.

Advice would be to throw your rationale to KOC so to as obtain the necessary deviation/concurrence.

Thanks.

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

 

[r6155]

SA 516 Gr 70 14mm & Inconel 625 3mm Cladding sound not good to me.
May be better to select 14 mm stainless steel.

Regards
r6155

 

[Kunal A]

Dear R6155,

The selection has been done as best economical option/as per code /considering 30 years of service.

Kunal Ajgaonkar.

 

[EdStainless]

For the explosive clad parts the person doing the bonding will spec the material, and my guess is that they will require solution annealed (soft) to optimize bonding.
That material does not matter unless you are taking credit for it as a pressure boundary, and even then as I recall you cannot claim higher strength than the underlying steel.
And if you normalize after forming you will have Gr1 anyway.
Now for your fittings and attachments it is a different story. Those will want to be Gr2. Finding pipe and bar in Gr2 shouldn't be difficult. Anyone that makes the material makes both flavors.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Kunal A]

Thanks EdStainless,


As in my initial post such material is available at manufacturer but at high delivery period.


I request to all seniors if they have any source for me which i can get material from please share.

Material:- Inconel 625 Solution Annealed.

2'', 3'' and 4'' Flanges, Pipes & SRNs.

3.2mm Thk 1250 mm L 3000 to 12000mm L plate.

These materials are very urgent for me to finalize the order.

Kunal Ajgaonkar.