Effects of Process Annealing on Mechanical Properties of Strain Hardened (Ns 34 Lc) Coiled Wire
Abstract
The effects of annealing on the mechanical properties of strain hardened coiled-rolled wire of low carbon steel, which is used for manufacturing barbed wire, office pins, nails and fencing were investigated in this paper. The as-received coiled-rolled wire was strain-hardened by drawing it through drafts of 30.56, 55.56, 75.00 and 88.89%, respectively. This was followed by process annealing at 400, 500 and 6500C. The tensile strength, yield stress, hardness, percentage reduction in area and percentage elongation of the annealed specimens were evaluated and compared with values for commercial specimens. The results obtained showed that NS 34 LC rolled coiled wire attains its full hardness or full brittleness at 88.89% strain hardening. It was observed that for optimal mechanical properties of cold worked coiled wire of the low carbon steel, the material should not be strain hardened beyond the drawing of 75% draft and should be critically annealed at 6500C for soaking time of 15 minutes before further deformation.
References
Callister, D. W. 2007. Materials science and engineering, an introduction. 7th Ed., John Wiley and Sons, Inc., NY.
Cetlin, P. R., Aguilar, M. T. P., Correa, EC, S., Valle, P. E. 1998. Influence of strain path in the mechanical properties of drawn aluminium alloy bars. Journal of Materials Processing Technology, Vol. 80 – 81 pp. 376 – 379.
Correa, E. C. S., Aguilar, M.T.P., Monteiro, W. A., Cetlin P. R. 2000. Work hadening behavior of prestrained steel in tensile and torsion tests. Journal of the Materials Science Letters. Vol. 19, pp. 779 – 781.
Fonteyn, D., Pitsi, G. 1990. Inelastic scattering in thermal transport properties of deformed copper single crystals. Journal of Low Temperature Physics, Vol. 80, pp. 325 – 332.
Guy, A. G., Hren, J. J. 1994. Elements of physical metallurgy, 5th Edition, Addison-Wesley Publishing Co. California, U.S.A.
Kalpakjiam, S. 1989. Manufacturing Engineering Technology. Addison Wesley Publishing Co. California, U.S.A.
Kouzeli, M., Mortensen, A. 2002. Size dependent strengthening in practice reinforced aluminium. Acta Metallurgical, Vol. 50, pp. 39 – 51.
Majta, J., Stefanska-Kqdziela, M., Muszka, K. 2005. Modeling of strain rate effects on microstructure evolution and mechanical properties of HSLA and IF-Ti steels. The 5th International Conference on HSLA steels, 8 – 10 November, 2005, Sanya, Hainan, China, pp. 513 – 517.
Majta, J., Zurek, A. K. 2003. Microstructure and deformation of microalloyed steels in the two-phase region. EPD Congress 2003 of the Extraction and Processing Division of the Minerals, Metals and Materials Society. In: Schlesinger, M. E. (ed), TMS, San Diego, pp. 63 – 81.
Mimura, K., Ishikawa, Y., Isshiki, M. 1997. Precise purity-evaluation of high-purity copper by residual resistivity ratio. Materials Transactions, Vol. 38, pp. 714 – 722.
Nestorovic, S., Tancic, D. 2002. Anneal strengthening effect in sintered copper-based alloys. International Conference on deformation and fracture in structural PM Materials, Slovakia, pp. 144 – 151.
NSO 1973. Nigerian Standard Organization. Methods for Torsion and Tensile Testing of Steel wires, Federal Ministry of Industries, Lagos, Nigeria.
Peeters, B., Bacroix, B., Teodosiu, C., Van-Houtte, P., Aernoudt, E. 2001. Work hardening/softening behaviour of B.C.C. poly-crystals during changing strain paths. Acta Materialia. Vol. 49, pp. 1621 – 1632.
Rauch, E. F., Gracio, J. J., Barlat, F., Lopes, A. B., Duarte, J. F. 2002. Hardening behavior and structural evolution upon strain of aluminum alloys. Scripta Materialia, Vol. 46, pp. 881 – 886.
Rollason, E. C. 1996. Metallurgy for Engineers. 5th Edition, Edward Arnold Publishers,
Zerilli, F. J., Armstrong, R. W. 1987. Dislocation-mechanics-based constitutive relations for material dynamics calculations. Journal of Applied Physics, Vol. 61, pp. 1816 – 1825.
