Authors: Martin Hunkel, Franz Hoffmann, Hans-Werner Zoch
Addresses: Stiftung Institut fur Werkstofftechnik, Badgasteiner Str. 3, 28359 Bremen, Germany. ' Stiftung Institut fur Werkstofftechnik, Badgasteiner Str. 3, 28359 Bremen, Germany. ' Stiftung Institut fur Werkstofftechnik, Badgasteiner Str. 3, 28359 Bremen, Germany
Abstract: A conventional low-alloy steel (SAE 5120, EN 20MnCr5) was extensively investigated by dilatometer experiments and at heat-treated cylindrical shafts to determine the three-dimensional anisotropic change in length and curvature during heat treatment due to segregations. The change in length due to the transformations during heating as well as during cooling can be detected as the main reason for distortion. Segregations are too small in relation to a whole part to simulate them for the entire part. This is the main problem with including segregations in a simulation model. Due to this a mean substitution had to be used. Segregations were taken into account by three-dimensional anisotropic transformation strains, which were implemented into the FEM-simulation program Sysweld®. Thereby, heating as well as cooling – including phase transformations and mechanical behaviour – were considered, because anisotropy occurs in both cases and its overlapping leads to the final distortion.
Keywords: heat treatment; distortion; microsegregations; low alloy steel; SAE 5120; simulation; cylindrical shafts; FEM; finite element method; cooling; phase transformations; mechanical behaviour.
International Journal of Microstructure and Materials Properties, 2008 Vol.3 No.1, pp.162 - 177
Published online: 17 Mar 2008 *Full-text access for editors Access for subscribers Purchase this article Comment on this article