Question A7: A metal bolt passing through, and in electrical contact with, a metal plate, is immersed in sea water as part of an engineering structure. Table A7: Galvanic Series for metals. (a) Using the information in the galvanic series in Table A7, select metals for the bolt and the plate. Regardless the price consideration, determine five possible combinations of metals for the bolt and the plate, in which the bolt will corrode preferentially with respect to the plate. [4 marks] (b) Discuss possible corrosion mechanisms for the bolt and plate structure in sea water, when metals are used for the structure. [3 marks] (c) Discuss methods and materials options to enable long life-time of the bolt and plate structure. [4 marks]