Simulation of central crack closing behavior during ultra-heavy plate rolling

The closing behavior of internal crack in the central of a continuous casting steel slab during rough transverse rolling was investigated using FE-code, ANSYS/LS-DYNA. Process parameters of ultra-heavy Q345 steel plate obtained from a Chinese iron and steel works were used as a reference. The results indicate that ξ, ζr,e, ηr,s,e, m and r are main influence parameters on crack closing during ultra-heavy plate rolling. The larger of ξ, ζr,e, m and the smaller of ηr,s,e, the more advantageous it is to crack closing. With other conditions unchanged, larger r is beneficial to close crack. For the rough transverse rolling process of 140 mm ultra-heavy plate in the works, the results reveal that the minimum r needed for rectangular crack closing is about 13.9%, which is 4% higher than that determined by the upper-bound triangular velocity field.