Influence of Tempering on Macro- and Micro-Residual Stresses and Yield Stress of Ferritic-Pearlitic Drawn, Coiled, and Straightened Wires

• DOI: 10.1007/s11661-022-06803-1
• Publication Date: 2022-09-15T18:12:18Z
• Authors: Marina Lukas; Michael Mayer; Andreas Stark; Bernhard Friessne...; Thomas Hönigmann; Matthew Galler; Gerald Ressel
• Keywords: Tempering

Residual stresses caused by different deformation steps during the processing of wiressignificantly affect the mechanical properties of the final product. However, in the literature,there is a lack of detailed information about their correlation with mechanical properties.Therefore, the proposed work focuses on the influence of tempering on the macro- andmicro-residual stresses, and related mechanical properties of a ferritic-pearlitic 27MnSiVS6 steelwire in the deformed state after hot rolling, drawing, coiling, and straightening. Characterizationof the wire in the deformed state indicates macro-residual stresses that remain high aftertempering at a temperature of 400 C for 10 minutes and decrease significantly after temperingat 475 C for 10 minutes. In situ high-energy X-ray diffraction measurements during heating ofwires in the deformed state reveal that micro-residual stresses remain unchanged up totemperatures of 200 C, while they decrease at 300 C. Investigations of the mechanicalproperties show that a reduction of micro-residual stresses correlates with a reduction of thecurvature of the stress–strain curve below the yield point, which increases the yield stress.Conversely, the reduction of macro-residual stresses begins in the temperature regime ofrecovery and relaxation, where a reduction of yield stress and tensile strength occurs.