The thixoforging forming process for steels makes it possible to produce complex shaped parts near netshape, or very close, in one step with a very low forging force compared to the conventional forging process. To obtain an optimal thixoforged product, it is necessary to have a mastery of the process parameters. The heating stage of the steel slug is a major phase in this process. It makes it possible to obtain a partially semi-solid billet allowing the thixoforging of the latter but also its prehension for transfer to the press. The article presents the temperature field in the volume of the semi-solid C38 steel billet obtained by experimental measurements and simulations. Under these conditions of heating the billets, it also shows the characteristics of the parts obtained, fibering and micrographs, and shaping, the necessary thixoforging force.