Sorry, such a metal alloy doesn't exist. 24 hrs is a short period of time, and a "saline solution" isn't all that corrosive. Switch to aqua regia or even dilute acid and you've got lots of choices...
An appropriate mixture of sintered powdered metal could work, such as steel/aluminum, steel/graphite. Or make your part a sacrificial anode by connecting it to a cathodic material. Rate will depend on exposed surface area and water flow.
I suspect there are "mixes of materials" that would work by providing an active galvanic couple (see post by "compositepro" above), but I ask first: what is the salinity, what is the temperature, is the system oxygenated and/or flowing?
"a usable wire"
Do you mean a wire used for structural use keeping something together, or lock wire, or suspending a load? Or a metallic wire that is used to make an electrical connection?
I apologise for not being more specific. I am after a wire to be created into a hook for marine research capture of fish. We have a hook that bends out and releases if the fish is too heavy but we must accidentally destroy many fish that are hooked but the hook remains or is swallowed. Is there a metal that corrodes quickly enough to allow the fish to survive.
