<p>Heat-resistant metal alloys designed for high-temperature applications in an oxidizing environment possess the ability to develop a protective oxide layer on their surfaces. The Fe–Cr based alloys like for example the Crofer ferritic stainless steels are the important class of such alloys. These alloys are commonly employed in high-pressure, high-temperature vessels and as metal connections in solid oxide fuel cells (SOFCs). Crofer stainless steels consist of ferrite α matrix and Laves phase strengthening precipitates. The morphology of Laves phase in the α/α grain boundaries (GBs) in Crofer 22 H alloy is studied in this work. The morphology of GB precipitates of the second solid phase depends on the ratio between the energy σ_αα of α/α GBs in the matrix phase and the energy of α/β interphase boundaries σ_αβ. If σ_αα &gt; 2σ_αβ, the second phase β forms continuous layers between the matrix α grains. In this case, one speaks about complete GB wetting by the second solid phase. If 2σ_αβ &gt; σ_αα, the second phase forms chains of lenticular particles in the grain boundary, and the incomplete (or partial) GB wetting is observed. In this work, we annealed the Crofer 22 H samples at different temperatures between 550 and 950&#xa0;°C during long time (600–3000&#xa0;h) in order to reach the equilibrium state. Thus, we observed for the first time the complete and incomplete wetting of α/α grain boundaries in the ferrite matrix of the Crofer 22 H alloy by the Laves phase (with Fe₂M structure, rich on Ti, W and Nb). Below 600&#xa0;°C all ferrite GBs are completely wetted by the continuous layers of the Laves phase. Between 600 and 900&#xa0;°C the portion of completely wetted GBs continuously decrease with increasing temperature from 100 to 0%. Above 900&#xa0;°C only incompletely wetted ferrite GBs are present in the Crofer 22 H polycrystals.</p> Graphical abstract <p></p>