I believe the oxidation occurred while waiting for repair. I don't believe it was fractured prior to total failure. But I did get more information. It is a driveshaft to the slide motor. This would mean it is subject to far more than human generated torque and actually exposed to the output of...
I have been a marine engineer technician with the Navy for 25 years, and I have never seen this kind of failure. It is a emergency crank handle for anretracting an RV slide. The 1/2" dia handle which appears to have failed under torsion split like string cheese. i have seen many sheared bolts...
