REVERSE TEMPER EMBRITTLEMENT - ENVIRONMENTALLY ASSISTED CRACKING INTERACTIONS IN FERRITIC LOW-ALLOY STEELS

This work attempts to assess the available data concerning reversed te mper embrittlement (RTE) effects in low alloy ferritic steels and to e valuate the influence of this embrittlement phenomena on the environme ntal assisted crack (EAC) growth, behaviour of low alloy steels in pre ssurised water reactor, (PWR) environments. It has been demonstrated t hat RTE could be anticipated in reactor pressure vessel (RPV) steels w ith the worst effects occurring in the heat affected zone (HAZ) region s. The segregation of residual elements to grain boundary locations ca n promote enhanced EAC growth processes in low alloy steels, viz., str ess corrosion cracking (SCC) hydrogen assisted cracking (HAC) and corr osion fatigue (CF). Hence, the possibility that RTE effects in RPV ste els can enhance EAC growth processes cannot be overlooked and studies including RTE-EAC growth interactions are required to determine the fu ture long term safe operation of working PWR facilities.