Formation Mechanism of Primary Carbide in H13 Steel During Electroslag Remelting Process
SUN Xiao-lin1,2，GUO Han-jie1，CHEN Xi-chun2，NING An-gang1,2，DU Guang-wei1，SHI Cheng-bin3
（1． School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing,Beijing 100083, China 2． Research Institute for High Temperature Materials, Central Iron and Steel Research Institute, Beijing 100081, China 3． Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 790784, Republic of Korea
Abstract：The eutectic carbide and nitride could precipitate the end of solidification during electroslag remelting process. Because of the high precipitation temperature and thermal stability they would finally remain in the product even through heat treatment, resulting in severe effects on mechanical performance for H13 hot work die steel. The segregation model was used to calculate and explain the possibility of forming coarsening eutectic carbide and nitride in the solidification process. When the solid fraction is 0.82, TiN can precipitate from the residual liquid and it is when approaching the end point of solidification that VC0.88 is formed with decreasing temperature. For the other soluble elements in the carbide, the carbide activity can’t be regard as unity, and the EDS analysis agrees well with the theoretical assumption. There is also a simple discussion on the characteristics of large carbide and nitride as well as refining size and reducing the amount of the primary carbide.
2014, Vol. 49 
