Experimental Study on The Effect of Processing Parameters on the properties of the Hot-Galvanized IF Steel Sheet

摘要

In this paper, The cold-rolling steel sheets produced by WISCO are subject to continuous annealing and galvanized under laboratory conditions. The experiments are arranged by three-factor and three-level orthogonal design. The factors are Annealing temperature, Annealing time and Al content in the Zinc bath selected as following: Annealing temperature is 770 deg C, 820 deg C, 870 deg C; Annealing time is 45s, 180s, 315s; Al content in the Zinc bath is 0.130. percent, 0.160 percent, 0.190 percent. The effect of Annealing temperature, Annealing time and Al content in the Zinc bath on mechanical properties and formablities of the Hot-Galvanized IF steel sheet are investigated by establishing the regression equations based on the experimental results and analyzing the contour map, graph and prediction. It is found from this research that the excellent mechanical properties and formablities of Hot-Galvanized IF steel sheets can be obtained if the processing parameters are properly selected. The appropriate processing parameters are: C<=0.0030 percent, N<=0.0050 percent, Continous annealing temperature: 810 deg C -830 deg C, Annealing time about 180s, Al content in the Zinc bath: about 0.18 percent; Zinc bath temperature: about 460 deg C, under these conditions, mechanical properties of the Hot-Galvanized IF steel sheet are: sigma_s<200Mpa, sigma_b:270-350Mpa, delta80>=38 percent, n>0.28, r>1.90.