Abstract: No matter what flatness of strip is whether flat or defective at anneal furnace entrance，strip can not keep it’s original shape and a remarkable large deflection has took place at anneal furnace exit. By tracking this phenomenon at 2030 continuous anneal line, the mechanics model of strip thermodynamics behavior in continuous anneal furnace is builded. The mechanism of flatness changes and the variations of these changes with the contributing factors are researched by the famous finite element software——ANSYS. Conclusions are achieved from the study, which may be used to improve technologies and decrease strip heat-buckling of 2030 continuous anneal processing line and hot galvanization line.

Key words: Anneal furnace, Cold rolled strip, Finite element method, Large deflection