Abstract：The jump fluctuation of impact value of 49MnVS3 automobile crank shaft was analyzedby meansof spark direct-reading spectrometer，Brinell hardness tester，scanning electron microscope（SEM），optical metallographic mi-croscope（OM）. Testing and checking for the surface quality of the impacted samples，notch geometry，machining dimension，chemical composition，hardness，appearance of fracture，distribution of the non-metallic inclusion，microstructure，as certain that the reason of the crack shaft impact testing data jump fluctuation and lower impact value are due to the non-standard position and direction of the impact sample.
2019, Vol. 37 
