Casting of a cold work steel alloy in semi-solid state

Semi-solid processing of metallic materials has already been investigated for some time, however, this innovative production process has not fully established in the industry yet. To broaden the field of application a lot of effort is put into the investigation of semi-solid high melting point alloy processing. The various chemical, physical and thermodynamic properties of steel alloys as for example the affinity to oxygen, the heat radiation and solidification, as well as the high forming temperatures combined with the intense high temperature corrosion, require sensible modifications of the machinery and process parameters. In order to understand and describe the material properties in the semi-solid state basic testimonies have been studied. Subsidiary numeric simulation helps pre-examing the heat distribution and revealing weak points of heating inside the die. Mold filling behavior and segregation phenomena were analyzed using various dies of which each was designed to evaluate characteristic process parameters. Extensive metallographical analysis of the pre-material, the re-heated billets and the produced parts have been done to evaluate the viability of the process. In order to validate the previously attained results of the basic samples more complex parts for accurately defined applications have to be investigated.