Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article A Comparative Study on Experimental and FEA-Based Simulation of Dry Sliding Wear Behavior of Boronized AISI 304 Stainless Steel at Elevated Temperatures(Pleiades Publishing Ltd, 2025) Gok, Mustafa Sabri; Kucuk, Yilmaz; Khosravi, Farshid; Gunen, Ali; Karakas, Mustafa Serdar; Guden, MustafaIn this study, the influence of boronizing on the high-temperature wear behavior of AISI 304 was examined experimentally and with FEA simulation. Boronizing, conducted at 950 degrees C for 3 h using the powder-pack boronizing technique, showed an approximately 7-fold increase in hardness compared to untreated sample. Boride layer characterization was performed using XRD, SEM, and EDS line analyses. Wear tests were performed at ambient temperatures of 25, 250, and 500 degrees C. While the wear rates of the untreated sample increased dramatically with increasing temperature, those of the boronized samples were significantly limited. FEA simulation using the Johnson-Cook fracture model demonstrated a high degree of consistency with the experimental wear profiles and this alignment enables reliable wear predictions. The oxide layer formation was observed on the worn surface of boronized samples during the tests at elevated temperatures, resulting in less plastic deformation.Article The Johnson and Cook Damage and Flow Stress Model Parameters of a Rolled Stainless Steel 304 Alloy(Elsevier, 2026) Akdogan, Ibrahim Berk; Davut, Kemal; Gueden, Mustafa; Erten, Hacer Irem; Tasdemirci, Alper; Maleki, Farshid Khosravi; Gok, Mustafa SabriPrevious studies on stainless steel 304 alloy (SS 304) have mostly focused on the stress-strain behavior as function of the volume fraction of deformation induced martensite and the applied strain and strain rate. Although equally important, the failure/fracture of this alloy has not been thoroughly investigated so far. In the present study, the Johnson and Cook (JC) damage model parameters of a rolled-SS 304 alloy, valid at a high strain rate (2900 s-1), were experimentally determined and numerically validated along with the JC flow stress parameters. The tensile failure strain of the alloy decreased as the strain rate increased from 10-3 to 10-1 s-1 and to 2900 s-1. Experimentally lower flow stresses at 2900 s-1 than at 1x10-3 s-1 were also found at the strains above 0.2, which was attributed to the adiabatic heating that declined the extend of the martensitic transformation at increasing strains. The determined damage and flow stress model parameters were further calibrated with the results of the numerical models of the quasi-static and high strain rate tension tests. Microscopic analyses and the hardness measurements on the untested and tested specimens confirmed the martensitic transformation and the highest hardness values were found in the specimens tested at 1x10-3 s-1. The martensite volume fraction as function strain rate until about necking strain (homogeneous deformation) was calculated and also microscopically determined using the electron back-scatter diffraction (EBSD) for the specimens tested at different strain rates. The results indicated the highest martensite volume fraction in the specimens tested at 10-3 s-1 (0.55-0.6) and the lowest in the specimens tested at the high strain rate (0.27-0.30). An agreement between the calculated and the EBSD determined martensite volume fractions was shown for the studied alloy.