Subsurface microstructure evolution and residual stress in 42CrMo4 steel after single-pass pendulum tests

Kimm, J.S. and Pöhl, F. and Wiederkehr, P. and Theisen, W.

Volume: 9 Pages: 1072-1080
DOI: 10.18178/ijmerr.9.8.1072-1080
Published: 2020

This work investigates the effect of cutting on the microstructure and subsurface properties of a cut specimen, with particular focus on the influence of the sample's microstructure and its evolution. Single-pass pendulum tests were conducted with samples of 42CrMo4 steel that had been subjected to different heat treatments. The subsurface region after cutting was analyzed optically by SEM and EBSD. The strain hardened surface region was investigated by nanoindentation. It was found that a soft-annealed structure, in particular, was altered deeply by cutting, resulting in a hardness increase as well as an microstructure that is elongated and refined by high shear deformation microstructure in near-surface regions. The strain hardening behavior and potential of a microstructure had a striking influence on the subsurface alteration. Although some microstructures yielded the same forces under equal cutting conditions, the subsurface alteration was different. This type of change in microstructure was correlated with the micromechanical properties and residual stresses. General influences, such as cutting depth, on the alteration of microstructures by cutting were also taken into account. © 2020 Int. J. Mech. Eng. Rob. Res.

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