Severe sticking occurs in the hot rolling of ferritic stainless steel B445J1M. The characteristics of the oxide scale on the steel in hot rolling are associated with this phenomenon. The tensile failure of the oxide scale formed on the steel B445J1M was investigated by using a Gleeble 3500 thermo-mechanical simulator over temperature range from 1000 to 1150°C in humid air. Two passes hot rolling were carried out on a 2-high Hille 100 experimental rolling mill. The results show that the temperature is a significant factor for the formed thickness of the oxide scale and its failure in tensile stress. On the specimen before hot rolling, irregular spinels are extruded from the surface of a thin oxide scale with Cr2O3 as its main component, which are hard and brittle at lower rolling temperature.