On the importance of thermodynamic investigations for the re-assessment of selected ternary Fe-base systems

International Symposium on Liquid Metal Processing & Casting 2015

材料科学;金属工艺学

Presoly, P.^1 ; Bernhard, C.^1

Ferrour Metallurgy, Montanuniversitaet Leoben, Franz-Josef-Straße 18, Leoben

A-8700, Austria^1

关键词: Calculation results;    High temperature phase;    Phase transformation temperature;    Ternary subsystems;    Thermodynamic data;    Thermodynamic database;    Thermodynamic description;    Thermodynamic investigation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/143/1/012034/pdf
DOI  :  10.1088/1757-899X/143/1/012034

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Reliable thermodynamic data are essential for the design and the production of new alloying systems. Particularly, the knowledge of the high-temperature phase transformations (TLiquid, TSolid, TPerit, Tγ→δ) are important for the solidification and the further processing. Investigations of selected commercial Dual-Phase, TRIP and high-Mn TWIP steels by DTA/DSC measurements show that the experimental results differ significantly from the calculation results of thermodynamic databases with respect to the phase transformation temperature and sequence. Based on these findings, it is very important to identify the defective subsystems of complex alloys in order to optimise the thermodynamic databases. In order to verify a quaternary system, e.g. the Fe-C-Si-Mn system, it is important to check the corresponding ternary subsystems. This was performed by DSC measurements of selected model alloys. By doing so, it was found that in Si- and Mn-alloyed Dual-Phase steels the thermodynamic description of the Fe-Si-Mn system is currently inadequate. This is a very important result, since all new designed steel grades for the automotive industry are based on a Fe-C-Si-Mn matrix.