Stacked couples of silicon carbide and Zircaloy-4 discs were annealed for 1 h in nominal inert atmosphere (6N Ar) at temperatures of 1200, 1400, 1500, 1550, 1575 and 1600°C. Strong interactions between silicon carbide and Zircaloy-4 occurred at temperatures of 1500°C and above. The width of the influenced zone exceeds 1 mm at 1550°C. A pronounced layer structure was found consisting of Zr-Si intermetallic compounds with different stoichiometry, the Zr-Sn intermetallic phase Zr2Sn and sub-stoichiometric ZrC1-x. The six different layers formed at temperatures of 1500°C and above contain these phases in diverse concentrations. At temperatures of 1575 and 1600°C, the discs welded together. This paper gives a detailed description of the results of the post-annealing examinations and an analysis of the interaction between the two materials.