Effect of Uneven Distribution of Material Property on Buckling Behavior of Strip during Hot Finishing Rolling

Abstract

Unlike traditional austenitic rolling, there is phase transformation during hot finishing rolling for thin gauge and high strength steel or non-oriented electrical steel. The transverse differences of temperature and asynchronous phase transformation result in uneven distribution of material property of rolled strip, further change the buckling behavior of strip during hot finishing rolling. By replacing the elastic modulus constant in the traditional buckling model with the distribution function of tangent modulus obtained by multiphase compression experiments and multifield coupling simulation, the effect of uneven distribution of material property on the critical buckling stress and buckling wave length are analyzed. The results show that for the global longitudinal wave, the critical buckling stress at the exit of stand is greater than that at the entry. But the opposite is true for the local longitudinal wave. Under the effect of uneven distribution of material property, the critical buckling stress and buckling wavelength of global and local center waves change little. The critical buckling stress of global edge wave is almost unchanged, but the buckling wavelength decreases slightly. The critical buckling stress and buckling wavelength of local edge wave are reduced obviously, and the buckling wavelength is decreased by about 10%. It means that the existence of soft ferrite at the strip edge easily makes the wave mode develop to "fragmented edge wave", which is consistent with the actual phenomenon.