To pickle or not to pickle

[VeryPicky]

The reactor vessel has been manufactured from 1.25%Cr 0.5%Mo weld overlayed with type 347 stainless.

I don't have information about the process conditions other than design temperature 420°C.

I am in favour of pickling and passivation after PWHT.
What is you advise?


Putting Human Factor Back in Engineering

 

[unclesyd]

Your question is short on details. A little hint as to the exposure would help immensely.

How big is the reactor?

How was the overlay applied?

Is the SS required for corrosion or product purity?

I would just physically clean the welds and let the PWHT do the passivation. There will be heat tint.

At your operating temperatures the benefits of pickling other than cleaning, in my opinion, are questionable. This is tempered by not knowing the process exposure or if you desire a clean, pretty, surface.