The effect of cold rolling and high-temperature gas nitriding on austenite phase formation in AISI 430 SS

Austenitic stainless steel is the most commonly used material in production of orthopedic prostheses. In this study, AISI 430 SS (0.12 wt. % C; 1 Si; Mn; 18 Cr; 0.04 P and 0.03 S) will be modified by creating austenite removing its ferromagnetic properties via high-temperature gas nitriding process. Cold rolling with various percentage reduction (30, 50, 70 %) was followed at a temperature 1200 °C holding times 5, 7, 9 hours, then quenching water carried out on as-annealed SS. The formation phase examined XRD (x-ray diffraction). microstructure element dispersion were observed using SEM-EDS (scanning electron microscope-energy dispersive spectrometry), whereas mechanical after determined Vickers microhardness testing. At all stages process, FCC iron indicated visible alloy's surface, although ferrite still present. intensity produced cold 5-hour time. Furthermore, nitrogen layer formed maximum thickness approximately 3.14 µm 50 hours process quenching. hardness reached 600 HVN condition. This due to distribution carbon that concentrated surface. As percent increases, strength can increase, causing an increase number dislocations. highest tensile 669 MPa 271.83 obtained %.