Influence of the phase balance and cooling conditions on the microstructure and corrosion behavior of solution-treated 1.4462 duplex stainless steel

In this study, effect of cooling rate on the microstructure and corrosion behavior of the solutiontreated \n1.4462 alloy was investigated. 1.4462 alloy was heat-treated at 1000 °C, 1120 °Cand 1200 °C \nfor different duration in order to obtain various phase balance. Two different cooling regimes (rapid \ncooling and steady cooling) were applied following the solution treatment processes. Also, effect of \nsigma phase was investigated together with ferrite and austenite phases for steady cooled samples. \nAfter heat treatment processes, samples were characterized by an optical microscope (OM), image \nanalysis and scanning electron microscope (SEM). Moreover, hardness tests and electrochemical \ncorrosion tests were applied. According to results, Ferrite ratio and ferrite grain size were increasing \nwith increasing solution treatment temperature and time. Also, ferrite phase was more dominant \ncompared to sigma phase for hardness of the solution-treated samples. Moreover, existing of sigma in \nhigher amount promoted the observation of Epit value.