隔片-孕育剂复合孕育工艺对D2钢铸态组织与偏析的改善OA

D2 steel(Chinese national standard grade:Cr12Mo1V1)is a high-carbon and high-chromium ledeburitic die steel,which has excellent hardenability and wear resistance and is widely used in the field of die manufacturing.However,its high carbon and chromium content easily leads to the uneven precipitation of eutectic carbides during the smelting and solidification processes,thereby affecting the mechanical properties and processing performance of the material.In this study,casting experiments were carried out,combined with metallographic microscope analysis and scanning electron microscope(SEM)observation technology,to systematically explore the regulatory effect of the composite inoculation process of spacers combined with inoculants on the as-cast microstructure of D2 steel,and clarify the mechanism of this process in grain refinement,improvement of element segregation and optimization of carbide distribution.The experimental results show that the single inoculant treatment has a limited effect on the overall grain refinement of the castings;the casting process with spacers can effectively refine the grain size,and different spacer thicknesses have significant differences in the grain refinement effect;the composite inoculation process with the synergistic effect of spacers and inoculants has the best grain refinement effect on the as-cast grains of D2 steel.Among them,the grain size of the optimal process group is reduced by 76％compared with that of the castings produced by the traditional casting process,which significantly improves the uniformity of the as-cast microstructure.