RESUMOQuando um sólido é imerso em plasma, dois tipos diferentes de transferência de energia ocorrem: por radiação e por colisão de partículas. No primeiro caso, a energia é transferida de maneira uniforme e paralela à superfície. No segundo caso, ela é transferida para as vizinhanças das micro-regiões onde os picos térmicos são ABSTRACTWhen a solid is immersed in plasma, two different types of energy transfer occurs: by radiation and collision of particles. In the first case, the energy is transferred evenly and parallel to the surface.In the latter case , it is transferred to the neighborhood of micro areas where thermal spikes are generated. In order to study these two effects , discs parallel to the samples made of AISI M35, whose hardness values are strongly temperature sensitive, were used as micro thermal sensors. By correlating hardness to temperature, it was possible to obtain the thermal profile of AISI M35 steel discs treated by plasma. It has been found that parallel disks with layers quenched by plasma had both surfaces (internal and external) of the containment that were not present in the furnace tempering resistive discs. Furthermore, it was found that discs with higher thermal gradients in plasma when annealed, were treated in the hollow cathode configuration with a pressure of 2 mbar and thermocouple at 550°C as the reference.