A stainless-steel mill in Germany operates continuous annealing furnaces that support demanding throughput and metallurgical quality requirements. Within one of its key annealing units, the refractory surfaces in three heating zones had begun to show reduced emissivity and early-stage deterioration. This decline risked lowering radiant efficiency, increasing fuel consumption, and introducing unnecessary thermal variability. These issues could ultimately impact production cost and process consistency. The plant’s objective was to restore radiant efficiency, protect refractory integrity, and enhance long-term thermal performance, all without interrupting the tight production schedule.