PSI - Issue 81

Jesús Toribio et al. / Procedia Structural Integrity 81 (2026) 54–57

57

2.0

1.5

1.0

R (GPa)



 

0.5

max

Y

0.0

1.0 1.1 1.2 1.3 1.4 1.5

exp   P /4)

Fig. 3. Embury-Fisher relationship betwwen strength (  Y and  max ) and cumulative plastic strain  p after drawing. (left); The afore-said modification is needed to account for the geometrical microstructural changes undergone by the steel during manufacture by heavy cold drawing, in particular (and specially) the progressive orientation of pearlitic lamellae tending to a direction close to the wire axis or cold drawing direction (i.e., the orientation angle  tending to zero), as reported in the past by Toribio and Ovejero (1998c). 5. Conclusions Interlamellar spacing in pearlitic steels decreases progressively during the cold drawing process and the diminishing rate increases at the final stages. At the same time, there is a progressive orientation of the pearlitic lamellar microstructure tending to a direction quasi-parallel to the drawing axis. The conventional yield strength increases with the cold drawing process, which is the final aim of the manufacturing process to obtain a high-strength material. There is a phenomenological relationship between microstructural evolution during cold drawing and improvement of mechanical properties, although the sort of functional relationship is not clear. In particular, fitting a conventional Hall-Petch type equation is impossible for heavily cold-drawn steels with markedly oriented microstructure. A modified Hall-Petch relationship is propose in the paper to account for the geometrical microstructural changes undergone by the steel during cold drawing, in particular the progressive orientation of pearlitic lamellae. References Alexander, D. J., Bernstein, I.M., 1989. Cleavage Fracture of Pearlitic Eutectoid Steel. Metallurgical Transactions 20A, 2321-2335. Choi, H.C., Park, K.T., 1996. The Effect of Carbon Content on the Hall-Petch Parameter in the Cold Drawn Hypereutectoid Steels. Scripta Materialia 34, 857 862. Dieter, G.E., 1988. Mechanical Metallurgy, McGraw-Hill , London, p. 189. Dollar, M., Bernstein, I.M., Thompson, A.W., 1988. Influence of Deformation Substructure on Flow and Fracture of Fully Pearlitic Steel. Acta Metallurgica 36, 311-320. Embury, JD., Fisher, RM., 1966. The Structure and Properties of Drawn Pearlite. Acta Metallurgica 14, 147-159. Hall, EO., 1951. The Deformation and Ageing of Mild Steel: III Discussion of Results. Proceedings of the Physical Society B64, 747 - 753. Hyzak, J.M., Bernstein, I.M., 1976. The Role of Microstructure on the Strength and Toughness of Fully Pearlitic Steels. Metallurgical Transactions 7A, 1217 1224. Langford, G., 1977. Deformation of Pearlite. Metallurgical Transactions 8A, 861-875. Lewandowski, J.J., Thompson, A.W., 1986. Effects of the Prior Austenite Grain Size on the Ductility of Fully Pearlitic Eutectoid Steel. Metallurgical Transactions 17A, 461-472. Nam, W.J., Bae, C.M., Lee, C.S., 2002. Effect of Carbon Content on the Hall-Petch Parameter in Cold Drawn Pearlitic Steel Wires. Journal of Materials Science 37, 2243-2249. Petch, NJ., 1953. The Cleavage Strength of Polycrystals. Journal of the Iron and Steel Institute 174, 25 - 30. Porter, D.A., Easterling, K.E., Smith, G.D.W., 1978. Dynamic Studies of the Tensile Deformation and Fracture of Pearlite. Acta Metallurgica 26, 1405-1422. Toribio, J., Ovejero, E., 1997. Microstructure Evolution in a Pearlitic Steel Subjected to Progressive Plastic Deformation. Materials Science and Engineering A234 236, 579-582. Toribio, J., Ovejero, E., 1998a. Microstructure Orientation in a Pearlitic Steel Subjected to Progressive Plastic Deformation. Journal of Materials Science Letters 17, 1037-1040. Toribio, J., Ovejero, E., 1998b. Effect of Cumulative Cold Drawing on the Pearlite Interlamellar Spacing in Eutectoid Steel. Scripta Materialia 39, 323-328. Toribio, J., Ovejero, E., 1998c. Effect of Cold Drawing on Microstructure and Corrosion Performance of High-Strength Steel. Mechanics of Time-Dependent Materials 1, 307-319.