EXPERIMENTAL CORRELATION BETWEEN HEAT TREATMENT PARAMETER AND CORROSION BEHAVIOUR OF 800 SERIES Ni-Fe SUPERALLOY IN HCl SOLUTION

Abstract

Experimental   correlation between heat treatment parameter and corrosion behaviour of 800Ni-Fe superalloy in HCl solution has been investigated.  The sample was produced by spark plasma sintering (SPS) and was heat treated at temperatures of 800 and 1000oC and time of 1 and 2hours at each temperature . Electrochemical studies were carried out in  HCl  medium, using potentiodynamic anodic polarization  technique.  From the results the heat treated alloy showed better  corrosion resistance  than the untreated alloy. Heat treatment temperature and time have great influences on the corrosion behaviour and morphology of the alloy. The sample heat treated at 800oC for 1hour gave a high protection efficiency of  75.33% .  It has been established that heat treatment can be used to improve the corrosion resistance of the alloy.