Test and analysis of the magnetic particle indication of 45MnVS crank shaft

The magnetic particle indication appeared on objected crank shaft which provided by the downstream forging plant was systematically tested and analyzed by dye penetrant inspection，magnetic particle inspection，metallography inspection and scanning electron microscope analysis. Combined with the principle of magnetic particle inspection，it was concluded that the magnetic particle indication belonged to capillary crack，whose essence was one segregation phenomenon of sulfide，and it could not affect the service performance of crank shaft.