Abstract
The surface states and thus the functionality of machined workpieces are influenced by parameters of the process and the cutting tool. Depending on these variables different mechanical and thermal loads lead to changing characteristics of components. This paper presents a 2D-FE-cutting simulation model predicting machining induced phase transformations of workpiece surface layers for the steel 42CrMo4 (AISI 4140) considering detailed friction modeling between tool and workpiece, based on tribological experiments. The cutting simulation model was developed using the commercial software ABAQUS. Friction and phase transformations are implemented using specific user subroutines. The model calculates the process of austenization and the transformed volume fraction of the phases ferrite/perlite, bainite and martensite. Additional thermo dynamical simulations of the heat transfer using the code INSFLA are performed. The simulated temperatures, cutting forces and phase transformations are compared to orthogonal cutting experiments.
Kurzfassung
Bei der Zerspanung beeinflussen Prozess- und Werkzeugparameter die Oberflächenzustände und damit die Funktionalität von Werkstücken. In Abhängigkeit dieser variablen Größen definieren unterschiedliche mechanische und thermische Belastungen die späteren Eigenschaften von Bauteilen. Dieser Beitrag stellt ein 2-D-Spanbildungssimulationsmodell vor, welches zerspanungsbedingte Gefügeumwandlungen der Bauteilrandschicht für den Vergütungsstahl 42CrMo4 abbildet. Dabei wird die Reibung zwischen Werkzeug und Werkstück auf Basis experimenteller Tribologieversuche detailliert modelliert. Die Spanbildungssimulation erfolgt mit der Software ABAQUS. Berechnet werden die Austenitisierung sowie die umgewandelten Volumenanteile von Ferrit/Perlit, Bainit und Martensit. Zur Berücksichtigung des Wärmeübergangs wurden zusätzlich thermodynamische Simulationen mit dem Code INSFLA durchgeführt. Die Validierung erfolgt mit Drehversuchen im orthogonalen Schnitt.
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