Inconel 625 versus Inconel 825

[casa903]

thread338-310345

With reference to the above thread Inconel 625 has superior external corrosion resistance in marine environment compared to Inconel 825. Hence Inconel 625 does not require painting compared to Inconel 825 which does require.

 

[Guest102023]

Why would you paint either of these expensive alloys?

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[casa903]

Inconel 825 is susceptible to external chloride pitting and hence to be used with external coating. Inconel 625 has no such issues.

 

[moltenmetal]

Wow, if you're worried about external chloride damage to 825, you're in a truly nasty environment.

 

[EdStainless]

825 is a high alloy stainless steel. It is more designed for elevated temp service than for corrosion resistance. A 6%Mo superaustenitic stainless (such as AL-6XN) will have much better pitting resistance.
In fact in aqueous chloride environments I would pick a 6% Mo alloy over 625.
If you really want better corrosion resistance move to a C alloy (C22, 686, 59), they are the same price as 625 and have far better pitting resistance.

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