the plating would work, but not for long since the cadmuim is a sacrificial coating. In other words the cadmium is a more active metal than the steel and therefore corrodes more readily, the cadmuim is sopposed to corrode to prevent the rotor from rusting.
If the conditions are as you describe then they would likely last 1 to 2 years before the plating has corroded away.
however, combined with a high temperature paint the cadmium plating will act as a second line of defense.
