Effect of titanium and rare earth microalloying on microsegregation,eutectic carbides of M2 high speed steel during ESR process

Fuxing Yin^1,2,3，Lu Wang¹，Zhixia Xiao^1,2,3，Jianhang Feng^1,2,3，Lin Zhao⁴

1. School of Materials Science and Engineering,Hebei University of Technology2. Research Institute for Energy Equipment Materials,Hebei University of Technology3. Tianjin Key Laboratory of Materials Laminating Fabrication and Interfacial Controlling Technology4. Central Iron and Steel Research Institute

摘 要：The effects of RE and Ti microalloying during electroslag remelting（ESR） process on the microsegregation and morphology of eutectic M₂C carbides in M2 high speed steel were investigated.The results show that the addition of 0.2 wt% RE can alleviate the segregation of C,W,Mo,V and Cr,while the morphology of eutectic M₂C carbides hardly changes.The microalloying with the addition of 0.5 wt% Ti has the lowest degree of microsegregation due to the improvement of primary dendrites by the effective heterogeneous nucleating agent of（Ti,V）（C,N） particles.The addition of Ti makes the mo rphology of M₂C carbides change from rod-like or maze-like shape into a coarse feathery shape,exhibiting anisotropic facet growth characteristics.For the microalloying of 0.2 wt% RE and 0.5 wt% Ti,the segregation of the main metal alloying elements is slightly more severe than that of the addition of only RE or Ti.Under the combined action of RE and Ti,the feathery eutectic M₂C becomes thinner and shorter and tends to be isolated or distributed in a discontinuous network.

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