@article{article_1688741, title={Investigation of The Effect of Accelerated Quenching Process and Quenching Parameters on The Strength of Low-Carbon Railway Forged Steel}, journal={Afyon Kocatepe Üniversitesi Fen Ve Mühendislik Bilimleri Dergisi}, volume={25}, pages={1439–1446}, year={2025}, author={Kirtiş, Halime and Elen, Levent and Türen, Yunus}, keywords={Çelik, Hızlandırılmış soğutma, Kendi kendini temperleme, Mekanik özellikler}, abstract={This study examined the impact of the ’Accelerated Cooling and Self-Tempering (AC-ST)’ heat treatment on the mechanical and microstructural properties of S355J2 grade steel forgings, specifically the component known as the ’Lower Side Bearer.’ The AC-ST heat treatment was conducted under 12 bar air pressure for a specific cooling duration. In the microstructure of untreated samples, a Ferrite+Pearlite phase was observed. With an increase in the cooling rate, the structure transformed into polygonal ferrite and/or acicular ferrite, followed by the formation of sorbite and/or upper bainite, and finally, martensite and/or lower bainite phases. It was noted that with an increasing cooling rate, martensite and bainite phases coexisted within the structure. At even higher cooling rates, the structure fully transformed into martensite. Additionally, the applied heat treatment was found to enhance the mechanical properties of the material. Especially, the highest value was obtained with 377 HB hardness value in the edge region of the sample with the highest cooling rate (1-fold distance). Similarly, the highest tensile strength (1002 N/mm²) and yield strength (663.93 N/mm²) were obtained in the 1-fold distance sample. However, in the 2-fold distance sample with lower hardness, the impact energy exhibited the highest value as 81.22 J at room temperature and 95.38 J at -20°C.}, number={6}, publisher={Afyon Kocatepe Üniversitesi}, organization={Karabük Üniversitesi}