Quantitative description of the material condition during profile grinding of transformable steels

• Applicants: Professor Dr.-Ing. Thomas Bergs; Professor Dr.-Ing. Christoph Broeckmann
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544951193

The functional performance of most highly stressed components increases with the surface and rim zone quality. In addition to dimensional accuracy and surface roughness, the microstructure, hardness and residual stresses of the rim zone are critical factors. To ensure that the component surfaces meet the requirements, they are often ground after heat treatment with grinding processes. However, the thermal overstressing of the rim zone during grinding processes leads to a change in its properties, such as hardness and residual stresses, which are specifically determined by the heat treatment. This results in a reduced service life for the manufactured component. As a result, complex tests must be carried out for quality assurance purposes, to ensure the continued functionality of the component. A precise understanding of the influence of the rim zone and its resulting properties as a function of the grinding process can increase productivity and reduce costs by eliminating the need of complex measurements in the quality assurance process. For profile grinding, the loading is dependent on the component profiles. This results in a profile dependent microstructure change. In order to achieve a targeted and knowledge-based adjustment of the microstructure conditions of the workpiece, it is essential to explain the change in material condition depending on the grinding process and the component profile. However, the effect of the initial microstructure on the resulting process force and heat, as well as on the rim zone properties after grinding, remains uninvestigated. Furthermore, it is impossible to predict the changes of microstructural in the material during profile grinding. The quantitative description of the stress on the component rim zone during grinding and the resulting surface integrity is still a current area of research. The overall objective of this project is to provide a comprehensive quantitative description and explanation of the influence of rim zones and their effect on the microstructural changes during profile grinding of hardenable steels as a function of the component profile and the initial condition of component microstructure. By systematically identifying the thermo-mechanical loadings and the kinematic engagement conditions for different component profiles during profile grinding, the change in material microstructure can be explained as a function of the initial condition of component microstructure and grinding process parameters with local resolution. A reliable process design for profile grinding can be achieved by knowing the condition of the rim zone after grinding, resulting in a high level of component quality.

• DFG Programme: Research Grants