Abstract
In order to meet with severer regulations of exhaust emission, FFV (Flexible Fuel Vehicle) operated by a blend fuel of gasoline and methanol are now under intensive development. However, critical failures can be expected to occur on the surface of SUS 440 C valve seat of fuel injector operated by the blend fuel M 85. Metallographic observations, FFV on-board durability tests, injector fuel-jet durability tests, and corrosion tests were carried out to confirm that failures caused by corrosion wear occur as expected, and the corrosive power of fuel becomes strong by blending with methanol in the case of trespassing of chloric acid in exhaust gas on the fuel. In order to supress the corrosion wear of the surface of valve seat, it is necessary to exclude the source of chloride ions, and apply new valve seat material with higher performance of anticorrosion than conventional SUS 440 C.
