Salt Water Damaged iPhone, Can I get the content off it?
What you described is called a boot loop.  It is caused by any number of things, but based on your description, it sounds like it was caused by physical damage. 

Can this be recovered?

Yes, but there’s no software that gets around a physical problem.   For this type of issue, it’s possible that restoring your phone from a backup you may be able to “fix” the problem.  However, any data not backed up can and will be lost.

There are 3rd party services that offer recovery services - iPad Rehab is one such example.  They are a bit pricy, but on the flip side, they don’t charge you unless they’re successful. (I’m not affiliated, just very familiar with their offerings)