| 摘要 |
PURPOSE: A method for manufacturing a pump piston for a fuel injection pump of a 4 stroke diesel engine is provided to minimize volume changes during a manufacturing process by lowering the volume fraction of retained austenite in a pump piston formed of bearing steel. CONSTITUTION: A method for manufacturing a pump piston for a fuel injection pump of a 4 stroke diesel engine comprises steps of: preparing bearing steel, a raw material of a pump piston(S100), heating and cooling the raw material to spheroidize carbon particles included in the raw material(S200), processing the raw material into a processed product(S300), heat-treating the processed product(S400), washing the heat-treated product(S500), transforming retained austenite in the product into martensite(S600), heat-treating the product to lower the retained austenite to 1.5volume%(S700), processing the heat-treated product(S800), and coating tungsten carbide carbon on the product to complete a pump piston for a fuel injection pump of a 4 stroke diesel engine(S900). |
