Alcohol-blended fuel is receiving increasing attention for its ability to provide cleaner automotive exhaust gas. Alcohol-blended fuel is however more corrosive than conventional gasoline and tends to corrode the materials of a fuel system. Use of nylon tubes or stainless steel tubes is now studied but is still accompanied by the unsolved problems of gas penetration and higher cost. As a technique pertaining to alcohol-blended fuel, single-wall tubes having excellent corrosion resistance have been developed by forming a Ni-base double plating layer on the inner walls of fuel pipes. Their corrosion resistance was evaluated using alcohol-blended fuel and the like.