Effect of Ce on α-Fe Grain Size and Austenite Growth Behavior of 10Cr5MoV Steel

The backscattered electron diffraction（EBSD）process is used to measure and analyze the grain size of α- Fe in two test steels，one containing no rare earth and the other containing Rare Earth Ce. And the results show that the addition of Rare Eearth Ce makes the α-Fe grain refined，and in turn forms the diffused fine rare earth inclusion as the heterogeneous nucleation core，which improves the-nucleation rate in the tempering process；the starting and ending times of the re-crystallization process is delayed by the dragging and pinning effects of the solution rare earth，and thus the driving force of the re-crystallization transformation increased，and in turn the re-crystallization generating temperature is reduced. The effect of Rare Earth Ce on austenite growth behavior is studied by means of getting the said two test steels austenitized with different austenitization processes. The result demonstrates that under the austenitization conditions of heating at 880~1 180 ℃ and holding for 30~90 minutes，the austenite growth index n and grain growth rate constant K of the test steel decrease，whereas the activation energy Q of austenite growth and the diffusion frequency factor M₀ of grain growth increase， which means that the addition of Ce has a certain inhibitory effect on the austenite growth behavior of the test steel.