Development of lead-free metal fuel tank. Hot-dip aluminum coated steel sheet evaluations for fuel tank applications

To prevent dissolved lead from draining into soil and underground water from the disposal of end of life vehicles (ELV) shredder residue, a lead-free vehicle development program has been initiated. As an alternative material to the present hot-dip lead-tin coated steel sheet (terne sheet), which has been in use for a long time, a hot-dip aluminum coated steel sheet was evaluated for fuel tank applications. The alternative material is more resistant to internal and external corrosion than terne sheet and this resistance is not degraded by form processing. The optimization of facility and welding conditions will guarantee air-tightness and reliability of welding. An additional organic film coating can improve productivity in forming and welding processes. More than half of the vehicles with metal fuel tanks in Nissan Motor Co., Ltd. have already adopted aluminum coated sheet technology.