The knives of my dinner cutlery service are and have been suffering from a crusting on the blades only, when washed in the dish washer. All other aspects of the service are OK.
I was advised at that time to remove any carbon steel knives from the area and see how I got on.
I am down to the point of not putting anything other than the basic knife, forks and spoons into the dishwasher, of the same set, along with the plates we have eaten from and the knives are still coming out of the dish washer with the same crusty brown marks on them. It is a raised from the blade sort of thing and doesn't look like it is eating into the metal.