Abstract:
A Joint of different materials type is significantly in car industry because it provides a flexible structure to allow functional efficiency of each material. Although, there is one major disadvantage that is weight which is affected directly to fuel consumption. Recently, Aluminum has been used for replacing structural steel to reduce the weight of car and it can decrease of fuel consumption. Therefore, research and development of a joint between Aluminum and Steel is continuously studied. This research aims to study the corrosion rate of AISI 1015 steel and AA 1100 aluminum lap joint in Thai marine environment as well as examine in the weight loss of the sample. The experiments were conducted under seawater condition in four areas; there are Phuket Marine, Maptaphut Industrial coastal, Laemchabang Industrial coastal and Manao Bay at Prajuab Kirikhan province. In order to pursue the results of this study for 30 days and then an analysis of corrosion rate and its mechanism which were occurred in the lap joint were conducted.
The results of this study indicated that the maximum weight loss of AISI 1015 steel and AA 1100 aluminum lap joint were occurred at Phuket Marine condition which loss 4.4395% and 10.1460% respectively. Moreover, it also indicated that the maximum corrosion rate of AISI 1015 steel and AA 1100 aluminum lap joint were occurred under the condition of Phuket Marine at 30 days which were 0.2472 mm/year and 0.6622 mm/year respectively. In addition, the results of Scanning Electron Microscope approach was found that there are many aluminum compound (A1) on metal surface which is caused from the galvanic corrosion in the inner zone of AISI 1015 steel and AA 1100 aluminum lap joint. This was caused the faster corrosion of AA 1100 aluminum.