The best advice for a lot of outdoor building products in the UK is simply to keep them clean and for aluminium gates a wash down with a light solution of soapy water is the best and easiest option for keeping any potential corrosion or paint damage away.

Moving sections such as the hinges or pins used for automation should be kept greased but are generally very well protected anyway from the weather

Think of an unwashed car compared to a regularly washed car for an obvious comparison...