Assuming the disc metal is steel it will tend to rust, and rust faster in contact with any dissimilar metal..........such as may be found in modern disc pads since we are no longer allowed to even mention the word 'asbestos'. A bloke I chatted to at Ford opined that pads these days have all manner of abrasive compounds and minerals in their formulations, 'close to concrete' in his words. That will make a nice conductive solution in the wet, so you have all that is needed for corrosion. If you're storing for a month it might be worth a try, but remember it will (and should!) 'burn off' the first time you brake.......
