تکامل ریزساختارها و TiC یوتکتیک جداشده در طی انجماد فولاد
Abstract
1- Introduction
2- Thermodynamic calculation on solidification path and segregation behavior
3- Modeling of the eutectic fraction
4- Experimental procedure
5- Results and discussions
6- Conclusion
References
Abstract
The effect of cooling rate on the microstructure and TiC precipitation of TiC-reinforced wear-resistant steel was investigated by different casting techniques. Thermodynamic and solute segregation modeling was performed to determine the evolution of TiC fraction in wear-resistant steel after rapid solidification. The evolution of TiC fraction due to solute segregation within the framework of Clyne-Kurz (C-K) model was examined. The model prediction is consistent with the experimental results.
Introduction
As transition metal carbide, TiC is characterized by its excellent properties such as very high melting point and hardness [1,2]. These properties have led to their wide applications as important precipitates for strengthening steels [3,4]. The volume fraction, particle size and distribution of the reinforcing phase are significant for improving the mechanical properties [5,6]. To obtain the desired wear resistant properties and mechanical strength of steels, it is important to control the volume fraction of TiC [7]. As it is known, the inevitable solute segregation occurred in non-equilibrium solidification process enriches the solute in liquid, and influence the amount of eutectic and other phases [8]. Quantitative prediction of microsegregation is complicated by the difficulties in accounting for eutectic and secondary phase formation in steel. Within the past decades, correspondingly various analytical models were developed to predict solute redistribution and related phenomena [9-14]. Among these microsegregation models, the Clyne-Kurz model is considered to be the most popular one. However, previous works have the disadvantage that a constant partition coefficient must be assumed.