INFLUENCE OF THERMAL TREATMENT ON STRUCTURE AND CORROSION PROPERTIES OF HIGH MANGANESE TRIPLEX STEELS

In this paper corrosion properties of X70MnAI28-9 TRIPLEX steel were tested after hot rolling and subsequent aging at 500 degree C for 6, 30 and 60 min. and at 600 degree C for the same times. For comparison related steels(X100MnAl28-12, X70Mn22, C20) were also used. The microstructure wascharacterized by light microscopy, SEM, energy disperse X-ray microanalysis. The corrosion behaviour of steels wasexamined by light and scanning electron microscopy, electrochemical techniques (potenciodynamic polarization method, linear polarization, using NaCl and H(2)SO(4) water solutions), salt spray test and gravimetric method. Aging has relatively small influence on corrosion resistance of X70MnAl28-9 steel. The localized corrosion in relation to structure and phases is discussed and compared in terms of dissolution, pitting and changes inchemical composition.