Deep Cryogenic Treatment (DCT) of cold work tool steels offers a great potential for improving the toughness without a significant decrease in hardness. Thus, it is used for post-treatment of highly loaded tools. Although the microstructural changes caused by DCT as well as their impact on the mechanical properties and the wear resistance are known, the information on the influence of DCT processes on the fatigue properties is limited. However, since cyclic loadings occur during a tool‘s lifetime, this knowledge is a prerequisite for the design of tools. Moreover, no efficient methods for the evaluation and validation of DCT processes exist, and hence, the development and adaptation of the DCT process parameters require long times and high experimental efforts.

Consequently, the main research objective of this project is the development of an evaluation concept for DCT processes. This concept is based on the short-time procedure PhyBaL_CHT, for which cyclic indentation tests (CIT) are used to efficiently evaluate the cyclic properties. For this, a sound knowledge of the correlation between DCT process, the resulting microstructure and mechanical properties, as well as the correlation to the measures obtained with PhyBaL_CHT is necessary. To develop the evaluation concept, detailed microstructural investigations, fatigue tests and cutting tests are planned, while the results obtained in these investigations are correlated to the results obtained in CIT.