TY - JOUR

T1 - Hardness Assessment Considering Nitrided Layers Based on Tempering Tests for Numerical Wear Prediction for Forging Processes

AU - Behrens, Bernd Arno

AU - Brunotte, Kai

AU - Wester, Hendrik

AU - Lorenz, Uwe

AU - Müller, Felix

N1 - Funding Information: The results presented in this paper were obtained within the research project “DFG 397768783“. The authors thank the German Research Foundation for their financial support of this project. This research was funded by the German Research Foundation (Deutsche Forschungsgemeinschaft—DFG), grant number DFG 397768783.

PY - 2022/10/13

Y1 - 2022/10/13

N2 - The nitriding of forging tools is an industrially established standard used to increase the hardness of the tool surface layer and reduce wear. However, this modification of the tool surface layer, as well as the microstructural changes that occur during this operation due to the thermo-mechanical load, cannot be considered during wear calculations with the widely used Archard wear model in the context of FE simulations. Based on previous work, this study further develops two tempering tests for the investigation of the hardness evolution of two nitride profiles based on H11 tool steel. Here, significant tempering effects could be observed depending on temperature, mechanical stress superposition and time. The results are used for setting up a new material model that is implemented in an existing numerical wear model. The validation is carried out in two laboratory forging test series. The evaluation shows that the hardness development in terms of tempering effects of a nitrided forging tool can be numerically predicted, especially for high forging cycles. However, due to the unexpected occurrence of adhesion effects, only limited applicability of the wear prediction then carried out is achieved.

AB - The nitriding of forging tools is an industrially established standard used to increase the hardness of the tool surface layer and reduce wear. However, this modification of the tool surface layer, as well as the microstructural changes that occur during this operation due to the thermo-mechanical load, cannot be considered during wear calculations with the widely used Archard wear model in the context of FE simulations. Based on previous work, this study further develops two tempering tests for the investigation of the hardness evolution of two nitride profiles based on H11 tool steel. Here, significant tempering effects could be observed depending on temperature, mechanical stress superposition and time. The results are used for setting up a new material model that is implemented in an existing numerical wear model. The validation is carried out in two laboratory forging test series. The evaluation shows that the hardness development in terms of tempering effects of a nitrided forging tool can be numerically predicted, especially for high forging cycles. However, due to the unexpected occurrence of adhesion effects, only limited applicability of the wear prediction then carried out is achieved.

KW - Archard model

KW - forging

KW - hardness modeling

KW - nitrided layer

KW - tool life

KW - wear calculation

UR - http://www.scopus.com/inward/record.url?scp=85140957235&partnerID=8YFLogxK

U2 - 10.3390/ma15207105

DO - 10.3390/ma15207105

M3 - Article

AN - SCOPUS:85140957235

VL - 15

JO - MATERIALS

JF - MATERIALS

SN - 1996-1944

IS - 20

M1 - 7105

ER -