Phase field study on evolution of carbides in surface layer of 20Cr2Ni4A steel gas carburized with rare earth addition
The addition of rare earth (RE) can increase the thickness and refine the microstructure of the carburized surface layer of steels.To account for the effect of RE addition on the microstructure in the carburized layer, the phase field method is used to simulate the precipitation of M3C (M =Fe, Cr or Ni) phases during 1133K RE carburizing and 1203K conventional gas carburizing.The microstructure evolution in the RE carburized layer shows that high-density M3C particles with a small size and spherical shape precipitate from the supersaturated austenite.The calculated results show that the addition of RE increases interfacial energies but decreases elastic energies,which play a significant role in the coarsening kinetic of M3 C particles, and also makes the stress and strain surpass the yield stress and critical strain of the austenite matrix, respectively, which results in the refinement of the austenitic grain by dynamic recrystallization.Our simulated results have been verified by experimental observations.
Phase field model Rare earth Carburizing Microstructural refinement 20Cr2Ni4 steel
ZHANG C S YAN M F WANG Y X YOU Y CHEN H T BAI B CHEN L LONG Z LI R W
National Key Laboratory for Precision Hot Processing of Metals, School of Materials Science and Engi China Academy of Engineering Physics, Mianyang , Sichuan, China 621900
国际会议
北京
英文
323-331
2014-10-11（万方平台首次上网日期，不代表论文的发表时间）