Investigation on decomposition behavior of austenite under continuous cooling in vanadium microalloyed steel (30MSV6)

Autor: Iman Raoofian, Mansour Zare, Vahide Ghanooni Ahmadabadi, Seyed Hadi Mohamadi Azghandi, Fateh Fazeli, Ahad Zabett, Hamed Reihani
Rok vydání: 2015
Předmět:
Zdroj: Materials & Design, Vol 88, Iss, Pp 751-758 (2015)
ISSN: 0264-1275
DOI: 10.1016/j.matdes.2015.09.046
Popis: In the present study, investigations are focused on microstructural evolution and the resulting hardness during continuous cooling transformation (CCT) in a commercial vanadium microalloyed steel (30MSV6). Furthermore, the effects of cooling rate and austenite grain size (AGS) on CCT behavior of the steel have been studied by employing high-resolution dilatometry. Quantitative metallography accompanied with scanning electron microscopy (SEM) has efficiently confirmed the dilatometric measurements of transformation kinetics and austenite decomposition products. A semi-empirical model has been proposed for prediction of microstructural development during austenite decomposition of the steel and the resultant hardness. The model consists of 8 sub-models including ferrite transformation start temperature, ferrite growth, pearlite start temperature, pearlite growth, bainite start temperature, bainite growth, martensite start temperature and hardness. The transformed fractions of ferrite, pearlite and bainite have been described using semi-empirical Johnson–Mehl–Avrami–Kolmogorov (JMAK) approach in combination with Scheil's equation of additivity. The JMAK rate parameter for bainite has been formulated using a diffusion-controlled model. Predictions of the proposed model were found to be in close agreement with the experimental measurements. Keywords: Microalloyed steel, Austenite decomposition, Modeling, CCT, Hardness
Databáze: OpenAIRE
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