Abstract: “In order to investigate the optimum conditions of the autofrettage process for the fuel injection pipe in diesel engine, different levels of autofrettage pressure, pressure rising time, pressure holding time, and repetition of autofrettage were applied. The autofrettage residual stresses in the fuel injection pipe were experimentally measured by using X-ray diffractometer. As the overstrain level increased, the magnitude of compressive tangential residual stress at the bore increased. It was found that the rising time to the autofrettage pressure, holding time at the autofrettage pressure, and repeated application of the autofrettage pressure had no significant influence on the residual stress distributions in the pipe.”

Keywords: Fuel injection pipe, Autofrettage, Residual stress