This thesis investigates the chemical interaction between the die casting mould and the aluminium melt. Six different hot working steels were analyzed, by varying temperature, the iron content, the holding time and the die hardness. Additionally purging the experimental station with argon was used to indicate potential influences at the transition region between aluminium melt and atmosphere. The formation of intermetallic phases was the main focus of attention during the dissolution of the die material. The aim of these scientific work is to give an evaluation of well-established hot working steels used in die casting moulds on the basis of some investigated characteristics (mass loss, formation of intermetallic layers, optical evaluation). During this experimental series in proper use of steel quality and hardness degree, evalutation is aimed at the die mould life time.