What I know about metallurgy can be written on a mini-post it, but the little I've gleaned from internet engineering and investigating the ceramic or titanium coatings of aluminum has been very successful with the major manufacturers of marine out drives and engine parts ie Volvo and Merc, and pump housings made for salt water use.
Although I do not the know the exact process of the 339 cermamized aluminum, the process of a ceramic coating is widely used to prevent corrosion in salt water.
If anyone does the exact process, I would welcome the info.
The exact process used by Panerai will help us to better understand the durability of one very special watch..the 339MM
"Life's an adventure, you might as well wear a Panerai"
Richardson Hwy, Valdez, Alaska-- The Brooks Range via Dalton Hwy Alaska--Prudhoe Bay/Deadhorse Arctic Ocean Alaska--Dawson Cr, Mile Marker '0' Alaska Canadian Hwy Alberta Canada--Yukon Territory, Al Can Highway--Crossing the Yukon River via The George Black Ferry from Dawson City--Poker Creek, population 2, furthest northern border crossing in Alaska. The Forty Mile River Region/Top Of The World Highway