Influence Factors Of Electrochemically Induced Annealing And Its Effects On Corrosion Resistance

The deformation induced martensite in metastable austenite stainless steels effect their physical and chemical properties. The martensite can be removed by electrochemical treatment, and the hardness of cold-worked stainless steel can be maintained. Influence factors, such as treating time, treating temperature, treating medium, electric pulse of voltage and electric pulse of pulse width, were studied in this paper. The results as fellows: the martensites amount in steel decreases with the increasing treating time. The decrease of martensites amount parabolic varies with increment of the temperature when the treating time is constant. The decrease of martensites amount reaches its maximum at 60~80℃. Electrochemically induced annealing is not only can occures in NaNO2 solution, but also can be occurres in many other solutions. The cathodic voltage is the most significant factor, the martensites amount decreases with the increasing cathodic voltage. The anodic voltage has little effect. Moreover, although the amount of martensites decreases markedly, the hardness almost kept a constant. The corrosion behavior was also studied by means of immersion test, anodic charging and electrochemical polarization. Results show that the electrochemically treatment promote the corrosion resistance of the 304L stainless steel.