Desensitization of aluminum alloys using pulsed electron beams

A method for controllably desensitizing a deckplate on a marine vessel, comprising:

• exposing a specific desired location on a surface of a deckplate to a controlled pulsed electron beam having a voltage greater than 100 kV to about 650 kV;
• wherein the electron beam is applied to the deckplate in situ on the vessel and is controllably directed to the specific desired location on the surface without exposing other areas on the deckplate to the electron beam;
• and
• wherein the electron beam heats a shallow surface layer of the deckplate having a desired depth at the specific desired location on the surface of the deckplate to a controlled temperature between a solvus temperature and an annealing temperature of the metal alloy without heating a bulk of the deckplate to controllably reduce a degree of sensitization of the deckplate at the specific desired location, an extent of a reduction in the degree of sensitization being controllable by varying at least one of a voltage, a current density, a pulse duration, and a pulse frequency of the electron beam.