Abstract
The research of the high temperature mechanical properties of Fe28Al4Cr with additives Ce, TiB2 and Zr is completed using as additive Zr combined with TiB2. The alloys were prepared using vacuum induction melting and rolling at 1200°C and finally applying annealing 1150°C for 2 hours.
During alloying the majority of Ti in TiB2 was replaced by Zr. The majority of (Zr,Ti)B2 particles is situated along the grain boundaries.
Fine ZrC carbide particles appear mainly on dislocations. Tensile and creep tests were performed at 600, 650, 700, 800 and 900°C.
Transmission electron microscopy showed precipitation of fine particles on dislocations, subgrain boundaries and also in the matrix. Coarsening of these particles during creep at 800°C and 900°C takes place.
The high temperature mechanical properties of alloys with additives Ce, TiB2, Zr and Zr combined with TiB2 are compared. The Larson-Miller parameter is used to describe the creep strength.