Akademik Veri Yönetim Sistemi
International Journal of Metalcasting, 2025 (SCI-Expanded, Scopus)
This study systematically investigates the effects of cryogenic treatment temperature and time on the carbide precipitation kinetics, microstructural evolution, residual stress distribution, and mechanical performance of austenitic steels containing 16-18% manganese. The as-cast material was subjected to an austenitization process and then rapidly cooled to room temperature to maintain the austenitic microstructure. Work-hardening mechanisms were induced by applying 10% deformation to the samples. At this deformation rate, no martensitic phase transformation occurred. Subsequently, cryogenic treatments were applied at −196 °C and −50 °C for 1 hour and 24 hours, respectively. Although no phase transformation occurred, an approximately 50% increase in hardness compared to the untreated material was observed due to twinning and deformation. Differential thermal analysis (DTA) and thermogravimetric analysis (TGA) were performed to determine the transformation temperatures associated with carbide formation. Microstructural characterization was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), while phase identification, carbide determination, and residual stress analysis were performed using X-ray diffraction (XRD). Wear behavior following heat treatments was evaluated by tribological tests, and surface topography was analyzed using a 3D profilometer. The results of the comprehensive characterization demonstrated that both the cryogenic treatment temperature and holding time play critical roles in determining the final material properties. In samples subjected to both deep and shallow cryogenic treatments, residual stress levels decreased by approximately 50% compared to the untreated reference sample.