The transition from gray to white cast iron during solidification : Part III. Thermal analysis

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2005-11, Vol.36 (11), p.3093-3101
• Main Authors: FRAS, E, GORNY, M, LOPEZ, H. F
• Format: Article
• Language: English
• Subjects: Applied sciences; Cast iron; Casting; Eutectics; Exact sciences and technology; Graphite; Metallurgy; Metals. Metallurgy; Solidification; Temperature
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-005-0081-8

In Part I of this work, an analytical model was derived based on the theory for the transition from gray to white cast iron during solidification. Accordingly, in this part of the work, analytical expressions were found that can be related to the chill width in wedge-shaped castings (or the critical pin diameter and critical wall thickness below which the chill is expected) with temperature parameters that are commonly measured by thermal analysis. Among these parameters are ΔT^sub c^ = T^sub m^ - T^sub c^ and ΔT^sub sc^ = T^sub s^ - T^sub c^, where T^sub m^ is the minimal solidification temperature for graphite eutectic, T^sub c^ is the transformation temperature for cementite eutectic, and T^sub s^ is the equilibrium solidification temperature for graphite eutectic. In particular, it was found that the analytical model agrees well with the experimentally measured temperatures. Measured values from thermal analysis for the excess-temperature range (ΔT^sub c^) and of the ΔT^sub c^/ΔT^sub sc^ ratios were found to be in good agreement with the theoretical predictions for the chill of cast iron. In addition, it was found that the predictions from the proposed analytical expressions are similar to those obtained from statistical analyses of the experimental outcome. [PUBLICATION ABSTRACT]