DISPERSION IN VALUES OF THE LANKFORD COEFFICIENT FOR A DRAWING-QUALITY, GALVANIZED, STEEL SHEET

M.A. BERTINETTI; J.W. SIGNORELLI; G. CHARA RAMOS; M. STOUT; R.E. BOLMARO; P.A.TURNER

Porto de Galinhas, PE, Brasil

Congreso; 18º CBECiMat - Congresso Brasileiro de Engenharia e Ciência dos Materiais; 2008

The Lankford coefficient is an effective tool for characterizing a sheets ability to be deep drawn. We measured the Lankford coefficients for a drawing-quality, galvanized, steel sheet tested in tension every 15 degrees between and including the rolling and transverse directions. In our experiments, we assessed the plastic strains at five separate points on each tensile sample by measuring the sample width and thickness before and after testing. These measurements allowed us the dispersion in the Lankford measurement as a function of orientation. Concomitant with the experimental measurements, we ran simulations to predict the Lankford coefficients based on a polycrystal plasticity model and the experimentally measured initial texture of the sheet. The results of these simulations as a function of angle to the rolling direction closely followed the average measured Lankford values. All of the variations can be successfully understood in terms of the initial sheet texture.