Experimental and Numerical Studies of Edge Cracks of a Silicon Steel Strip in Cold Rolling

Abstract

We examined the edge cracking behavior in a silicon steel strip, caused by waviness using a pilot rolling test. The specific results of this waviness are that the edge (or side) portions of the strip are stretched, and the center is compressed in the rolling direction due to different deformation conditions. We designed roll grooves shaped to reflect the role of roll bending, which generates waviness in the strip in an actual cold rolling process, into the pilot rolling test. The material used in the rolling test was high-silicon steel (about 3%). A series of three-dimensional finite element analyses was also performed to quantitatively investigate the stress distribution in the strip specimen when subjected to different deformation conditions during rolling. Results showed that fracture in the strip specimen initiated and propagated when waviness occurred at its center. The tensile stress created on the strip edge by the center waviness toward the rolling direction is a crucial factor that produces the edge cracking.