Abstract: To improve the cleanliness of 42CrMoA crankshaft steel ,and reduce the gap between 42CrMoA crankshaft products and imported products，the inclusion type, composition, size, quantity and distribution in different parts of 42CrMoA were analyzed. The evolution of inclusions in steel during refining and solidification process was analyzed. Inclusion distribution in crankshaft steel ingot was determined. The result showed that the inclusions in refining process were mainly composed of CaO, Al2O3 and MgO, while the chemical composition of inclusions were mainly CaS, CaO, Al2O3, MgO in the ingot. Most of inclusion morphology were spherical and block. The number of inclusion in the lateral direction was less external and more internal, and decrease gradually from the head to the tail.

Key words: 42CrMoA crankshaft steel, inclusion, component analysis, distribute regulation