Discussion about the strength and microstructure of 42CrMo quenched and tempered steel products for crankshafts

The 42CrMo steel products for automobile crankshafts with different contents of Ni and Mo were studied by quenching and tempering with different kinds of quenching medium. After the heat treatment，the mechanical properties and microstructure of the steel products with different chemical contents were tested and compared. It was testified that the mechanical properties of steel products could be previously improved，and uniform microstructure could gain by means of increasing the contents of Ni and Mo in steel and employing quenching medium with fast cooling rate.