Abstract: The continuous cooling transformation (CCT)curves and time temperature transformation (TTT) curves of H13 die-casting die steels with different mass fractions of V were measured by dilatometry. The effects of V on the phase transformation points (Ac1, Accm and Ms) CCT curves, TTT curves and hardness of H13 die-casting die steels with different mass fractions of V were studied by scanning electron microscopy (SEM), Vickers hardness test and X-ray diffractometer (XRD).The results show that the Ms of H13 significantly increase, pearlite and bainite phase regions in CCT curves and TTT curves shift to the left, critical cooling rate of pearlite and bainite phase regions in the CCT curves increase, and the quenched hardness decreases with the increase in mass fraction of V. Subsequently, our work also explored the mechanism about the effect of different mass fractions of V on the phase transformation characteristic. It can been seen that more stable V-based carbides are formed with the increase in mass fraction of V, which reduce the carbon content dissolved in the matrix during the complete austenitizing process, and then reduce the stability of the undercooled austenite. Eventually, the pearlite and bainite transformations are promoted, which means the pearlite and bainite phase regions in the CCT curves and TTT curves are shifted to the left.
1 夏书文,左鹏鹏,吴晓春.模具制造,2017(7),93. 2 Chen X, Li Y X. Materials Science and Engineering A,2007,444,298. 3 Capdevila C, Garcia-Mateo C, Cornide J, et al. Metallurgical and Materials Transactions A,2011,42(12),3743. 4 He K, Edmonds D V. Materials Science and Technology,2002,18(3),289. 5 唐静.金属热处理,2013,38(9),92. 6 李志超,张小垒,米振莉,等.材料热处理学报,2015,36(7),125. 7 李翼,杨忠民.金属学报,2010,46(12),1501. 8 Niu G, Chen Y L, Wu H B, et al. Journal of Iron and Steel Research, International,2016,23(12),1323. 9 Gan X L, Yang G W, Zhao G, et al. Steel Research International,2018,89(9),112. 10 Wu D, Wang F M, Cheng J, et al. International Journal of Minerals, Metallurgy and Materials,2018,25(8),892. 11 徐骏,杜振民,张奇真,等.北京科技大学学报,1992,14(6),681. 12 张黄强.合金钢CCT曲线研究.硕士学位论文,武汉科技大学,2008. 13 Liu X, Zhong F, Zhang J X, et al. Physical Review B,1995,52(14),9970.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2020, Vol. 34 
