Rust is not chain-specific. Rust will occur with any iron. Steel is mostly composed of iron.
Because salt is an electrolyte, it promotes the rusting process. Rust is the result of oxidation, and salt increases the amount of oxidizing agents in the environment.
When exposed to salt, any metal will corrode more quickly and severely. Even a pinhole in your paint will develop into a rust spot.
With regards to chains, they probably have a little more oil and lubricant than the rest of your bike. This may provide some temporary protection until it is washed away.
Chains are available in plain steel or, more rarely, stainless steel. Occasionally, plain steel chains are powder-coated, although this provides little protection for the chain’s rolling contact surfaces. While stainless steel is more durable in general, it is not immune to corrosion.
It makes little difference whether it is road salt that some areas spray about in the winter or sea salt that has been derived from saltwater or sea spray; I believe there is no difference.
Defend yourself from dark salts:
The best course of action is to avoid salt. At no point should you ride across the ocean.
If your bike has been exposed to salt during your ride, thoroughly clean it afterward. It is very unusual for individuals to wash after swimming in the water; why should your bicycle be any different? Avoid power washers; all you want is for it to rain for a time, preferably not on a lawn. Carry out this procedure as soon as feasible after your salty ride. Allow it to air dry and then relube the chain before storing the bike; this will ensure that you may hop on and ride with little preparation the following time.
If you frequently expose the bike to salt, you should increase the frequency of your regular bearing repair.
There are antirust coatings available, but they are better suited for use on frames and other internal components than on chains.
Finally, keep in mind that chains are consumable and should be replaced every 2000 miles. Perhaps you can reduce your chain change interval to 1500 miles. These are not prohibitively costly goods.