Sulfate stress corrosion cracking of Cu-alloys 1

[shvet]

Good day, forum

According to para. 4.5.8 API 571-2011 copper-based alloys are susceptible to stress corrosion cracking in contact with sulfate solutions. Is pump impeller made of 1.4517 duplex SS (2.8-3.5% Cu) suitable for periodic pumping of a sulfate solution.

 

[EdStainless]

Cu based means that Cu is the predominant component of the alloy.
A few % Cu in a SS will be fully in solution and will not behave like a Cu alloy.
Cu bearing SS are commonly used in sulfuric acid service.

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P.E. Metallurgy, Plymouth Tube

 

[Chumpes]

i confirm DSS are not Cu-alloys

 

[MortenA]

thers not supposed to be any Cu i duplex steel?

 

[EdStainless]

Many stainless grades, both duplex and austenitic have Cu in them.
It is a weak austenite stabilizer and it aids in some acid resistance.

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P.E. Metallurgy, Plymouth Tube