F20 VS F316

[zulsaid]

Dear All,

I would like to know how is the corrosion resistance performance between F20 and F316.In terms of chemical composition F20 has higher Nikel and Chromium compare to F316.
Is there any possiblity I do passivation or do nickel/chromium coating to F316 and gives same corrosion resistance same as F20.

 

[EdStainless]

In general higher Cr = higher corrosion resistance.

Passivation is cleaning operation intended to remove free iron from the surface of stainless steel. The passive file forms naturally. Proper anneal, pickle, and passivation allows you to optimize the corrosion resistance for a specific chemistry.
While you can get a slight enhancement of the surface chemistry due to selective removal of Fe this effect is only on the surface and any damage will go below this layer.

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Plymouth Tube

 

[strider6]

You should specifiy in which environment. As Ed said higher alloing elements generally means higher resistance but this is a general rules. Then there are other factors, fluid composition, temp, pressure,...., that determine the corrosion resistance of a material.

S.

Corrosion Prevention & Corrosion Control

 

[zulsaid]

Thanks Ed and Strider6,

Actually we already proposed to use 316 for the ball of the valve(our standard design).
But unfortunately, our customer want to change to F20, for us no problem to change it.Our problem is our material supplier not very familiar of this grade might very seldom produce in the market.