IMPROVING THE WELDABILITY OF FeCrAl ALLOYS THROUGH TiC ADDITIONS

FeCrAl alloys were prepared with TiC additions to act as hydrogen traps and improve resistance to hydrogen cracking. Weldability results showed that alloys with up to 20 wt% Al and 11 wt% Cr could be prepared crack-free with relatively small TiC additions of ~ 4 wt%. Thermogravimetric analysis of Fe-10Al-5Cr corrosion coupons with and without TiC has shown that the corrosion resistance is not significantly affected by the presence of the second phase. These results suggest that TiC can be used to decrease the hydrogen cracking susceptibility of FeAlCr based alloys, which are candidates for use in weld overlay applications in coal-fired boiler tube fabrication. A solidification model was developed as an aid to control the TiC content in FeCrAl alloys.