This thesis deals with the process chain cleaning-hardening and tempering-nitriding of high-alloy materials, such as hot-work steel X40CrMoV5-1. The process chain should be analyzed, and by a detailed analysis of all pretreatment steps the effects of this should be determined. The aim is to ascertain why the pickling with hydrochloric acid is necessary before nitriding, and to possibly eliminate this intermediate step in the future to optimize the process chain. The experiments are set up on the basis of current literature, where great attention is paid to the cleaning and the formation of oxide layer. With numerous experiments which contain various cleaning, annealing and nitriding parameters, an improved process chain should be determined which does not contain the pickling process. The results show that the cleaning is a minor point compared to the annealing process. This has proven to be the most important step in this process chain. If this is not done properly, chromium oxide will be generated on the surface, which blocks the diffusion of nitrogen and leads to poor nitriding.