The high heat transfer rates and flow pattern were investigated in the vicinity of a 90-deg axial corner at a Mach number of 6 and over a Reynolds number range from 7 to 22.5 x 10(6). The investigation was carried out for two different corner configurations, one that involves two 9-deg half-angle unswept intersecting wedges and the other one that consists of a 9-deg half-angle unswept wedge and a flat plate aligned with the freestream. In this study it was observed that, in some cases, there are three and even four peaks of aerodynamic heating in the corner region. To give a reasonable physical explanation for the results of the experiments, two different vortex systems have been developed qualitatively in the boundary layer. A sharp decrease of heating detected in the region very near the corner centerline is attributed to the mutual interaction of the surface boundary layers, as also indicated in the literature, and a pair of small vortices causing the flow to lift off the surface.