Assessment of Retained Austenite in Fine Grained Inductive Heat Treated Spring Steel

0521751 - ÚJF 2020 RIV CH eng J - Journal Article
Olina, A. - Píška, M. - Petrenec, M. - Hervoches, Charles - Beran, Přemysl - Pechoušek, J. - Král, Petr
Assessment of Retained Austenite in Fine Grained Inductive Heat Treated Spring Steel.
Materials. Roč. 12, č. 24 (2019), č. článku 4063. E-ISSN 1996-1944
R&D Projects: GA MŠMT LM2015056
Institutional support: RVO:61389005 ; RVO:68081723
Keywords : spring steel * heat treatment * retained austenite * Mossbauer spectroscopy * neutron diffraction
OECD category: Condensed matter physics (including formerly solid state physics, supercond.); Materials engineering (UFM-A)
Impact factor: 3.057, year: 2019
Method of publishing: Open access
https://doi.org/10.3390/ma12244063

Advanced thermomechanical hot rolling is becoming a widely used technology for the production of fine-grained spring steel. Different rapid phase transformations during the inductive heat treatment of such steel causes the inhomogeneous mixture of martensitic, bainitic, and austenitic phases that affects the service properties of the steel. An important task is to assess the amount of retained austenite and its distribution over the cross-section of the inductive quenched and tempered wire in order to evaluate the mechanical properties of the material. Three different analytical methods were used for the comparative quantitative assessment of the amount of retained austenite in both the core and rim areas of the sample cross-section: neutron diffraction-for the bulk of the material, Mossbauer spectroscopy-for measurement in a surface layer, and the metallographic investigations carried by the EBSD. The methods confirmed the excessive amount of retained austenite in the core area that could negatively affect the plasticity of the material.
Permanent Link: http://hdl.handle.net/11104/0306328