bronze and Ni-Cu alloys for seawater

[rmetzger]

We are looking to replace some titanium and stainless parts with a lower cost / easier to source material and I was exploring 651 silicon bronze, aluminum bronze, and 70-30 and 90-10 copper nickel alloys. There are two applications that are of primary importance:
(1) a lead screw (30 PSI tensile/compression) exposed to salt spray.
(2) a stationary non-structural piece (electronic housing).

The screw can have anode protection installed but the electronic housing cannot (limited exposed surface). On the latter the reduction of bio-fowling is as important as corrosion as this is a set and forget device. Any suggestions based on experience and costs?

thanks

 

[EdStainless]

If you really want seawater resistance you are looking at NiAlBronze or 70/30. The other alloys will sort of work, but nothing like a 6% Mo stainless or Ti.

You won't save much money. One advantage of the Cu based alloys is the biocide effect. As long as you are allowed to have a release of Cu ions you can take advantage of this.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[rmetzger]

any particular grade of Ni Al Bronze? I was looking at C62300 and C95500 initially.

 

[EdStainless]

955 is the one that I have used in seawater.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm