Abstract
The effects of Ni content and microstructure on the embrittlement of Fe-26% Cr alloys containing up to 10% Ni by reheating at a temperature range of 400 to 750°C were investigated. Furthermore, mechanical properties at low temperatures of ferritic alloys in annealed conditions were also investigated and the following results were obtained.
(1) The addition of Ni to high Cr ferritic alloys promoted the occurrence of deformation twinning during tensile test.
(2) The fracture of Fe-26% Cr ferritic alloy tested at- 196°C occurred without any plastic deformation, but the alloy containing 6% Ni exhibited a good ductility and strength due to the work- hardening effect of deformation twins.
(3) The peaks of embrittlement by reheating were observed at 450, 500 and 750°C in case of the ferritic alloy annealed at 1000°C, while the embrittlement peaks of the two phase alloy were observed at 500 and 750°C.
(4) The embrittlement of the ferritic alloy appeared within short heating times in comparison with the phase alloy that produced the embrittlement after long heating times. The causes of embrittlement observed at 750°C were different each other.
