wouldn't it be true that its not a full 316 piece of stainless? Its just surface altered? In that case what you have to do Wet dreams is seal it with something before shipping or find a supplier that sells 316 that is full thickness. I work with up to 2" plate 316L which we machine up to .5" off on mating surfaces. They are put in 100*F constant wet conditions and have zero rust on them after 60 years of service. Moisture can seep into the mating surfaces since its not 100% critical to be super flat and can sit there indefinitely . Therefor I believe that what you are getting is either poop steel or the laser is changing the properties of the metal during the process.