Ratchetting in Cold-Drawn Pearlitic Steel Wires
- PDF / 1,900,623 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 35 Downloads / 342 Views
I.
INTRODUCTION
COLD-DRAWN pearlitic steel wires that consist of alternating lamellae of body-centered cubic (BCC) ferrite and orthorhombic cementite are used widely as engineering structures, such as arrester wires of aircraft carriers, suspension bridge cables, and tire cords owing to their excellent combination of high strength and reasonable ductility.[1] Mechanical properties of colddrawn pearlitic steel wires are controlled mainly by precipitations of cementite in ferrite phase, although the hard cementite phase accounts for only approximately one-ninth of the total volume in pearlite. Hence, the formation and evolution of cementite have been studied extensively over the past decades.[2–35] The deformation and slip planes of cementite in pearlitic steels have been investigated.[2–6] Many studies have reported that cementite undergoes dissolution during cold drawing.[7–17] The partial amorphization of cementite in heavily drawn eutectoid steels was found.[18–20] Some studies indicated that cementite should be considered as an interstitial phase Fe3C1x,[21,22] although cementite is commonly regarded as a stoichiometric compound
LUNWEI LIANG, YUNJIANG WANG, YAN CHEN, HAIYING WANG, and LANHONG DAI are with the State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, P.R. China and also with the School of Engineering Science, University of Chinese Academy of Sciences, Beijing, 101408, P.R. China. Contact e-mail: [email protected] LIANG XIANG is with the State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences and with the School of Engineering Science, University of Chinese Academy of Sciences, and also with the Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang, 621999, Sichuan, P.R. China. Manuscript submitted December 7, 2018.
METALLURGICAL AND MATERIALS TRANSACTIONS A
Fe3C. Recently, atom probe field ion microscopy three-dimensional atom probe (APFIM),[23–25] (3DAP)[24,26–29] and Mo¨ssbauer spectroscopy[30–34] studies have reported that cementite dissolves during cold-drawn deformation at room temperature. Two main mechanisms of cementite dissolution have been proposed. The first mechanism is attributed to the interaction between dislocations and carbon atoms, since the binding enthalpy between the carbon atoms and the dislocations in ferrite is higher than that between carbon and iron atoms in cementite.[7,35] The second mechanism is ascribed to the destabilization of cementite because of an increase in free energy.[8,10] Ratchetting,[36–38] which is a cyclic accumulation of inelastic deformation that is generated from an asymmetric stress-controlled cyclic loading, can reduce the fatigue life of engineering structures.[39] Some components made from pearlitic steels, such as steel wire ropes in mine hoists and tower cranes, inevitably undergo ratchetting during cyclic starting and braking. It is critical to investigate the ratchetting behavior of pearlitic steels for safety ass
Data Loading...
