the effect of heat treatment and cold-work on precipitation and recrystallization of biodur108 hns steel

hns (high nitrogen austenitic stainless steel) steels are attractive materials due to their unique combination of outstanding mechanical and corrosion resistance properties in medical and industrial applications. however, despite the excellent traits, brittle precipitates formation during aging would subvert the structure. many studies performed on the aging reactions and the nature of deposits. this paper focuses on the effect of heat treatment and cold-work on precipitation and recrystallization behavior in the sensitive deposition zone of biodur108 hns. for this purpose, samples of high nitrogen austenitic stainless steel with cold-work values of 0, 40 and, 60% were subjected to isothermal annealing at 4 temperatures of 850, 900, 950 and 1000 ° c, a constant time of 30 minutes and, followed by water quenching. microstructural characterization was carried out via optical microscopy and, eds tests. vickers hardness was carried out. in all cold-worked samples, recrystallization occurs before deposition. sensitive deposition temperature is 950, 900 and 850°c, respectively for 0, 40, and 60% amount of cold-work. increasing the percentage of cold-work causes the transfer of sensitive deposition temperature to lower. no carbide is formed and, the precipitates, during annealing in cold-worked samples, are the predominant cr2n and sigma phase. the main cause of the hardness increase is cr2n deposition.