Investigation on environmental assisted fracture behavior of iron aluminides using moire interferometry

Comparative crack growth tests of Fe–28%Al iron aluminide alloys (all with basic composition of Fe–28Al–5Cr at.%, with micro-alloying additives of Zr, C or B) under air, oxygen, or water environments were conducted using moire interferometry. Test results showed that the alloys are susceptible to room-temperature hydrogen embrittlement in both B2 and DO3 conditions, and FA-187 and FA-189 are intrinsically more brittle than FA-186.