Heterogeneous nucleation of carbides attached to Y2O3 in Y-modified H13 steel

Heterogeneous nucleation of rare-earth (RE) oxides has recently been recognised as an effective approach for optimising the precipitation behaviour of carbides in steels. Further investigation of heterogeneous nucleation induced by RE oxide or oxygen sulphide in steels is essential. Taking the 0.013Y-H13 die steel as an example, we clearly revealed the critical role of heterogeneous nucleation in terms of interface relationships, lattice structures, and element distributions. There are many submicron scaled Y2O3 phases, which have obvious heteromorphic nucleation effects on carbides such as VC and Cr23C6. Among them, part of heterogeneous nucleation is an associated mutual diffusion behaviour between carbides and Y2O3. As a result, Y occur at the phase interface with a stacking fault structure, C-Cr nanoclusters exist in Y2O3, and Y is solid soluble in Cr23C6. Our work, not only provides important insights into the intrinsic nature of heterogeneous nucleation induced by RE oxides but also clearly expounds the associated mutual diffusion behaviour between carbides and RE oxides.

Automated summary

Heterogeneous nucleation of rare-earth oxides is an effective approach for optimizing the precipitation behavior of carbides in steels. In this study, the critical role of heterogeneous nucleation in interface relationships, lattice structures, and element distributions was revealed in 0.013Y-H13 die steel. The presence of submicron scaled Y2O3 phases induces heteromorphic nucleation effects on carbides, such as VC and Cr23C6, with mutual diffusion behavior between carbides and Y2O3. Our work provides important insights into the nature of heterogeneous nucleation induced by RE oxides and the associated mutual diffusion behavior between carbides and RE oxides.