Abstract: During continuously casting of steel slabs production, the presence of surface and internal defects takes place. These defects can include cracks, voids, coarse non-metallic inclusions and heavy local chemical and microstructural segregation. Many NDT techniques have been developed and used to assess the presence of these defects. The factors responsible for these defects are often related to mechanical, thermal, or transformation stresses during the solidification process of the slabs. The high thermal stresses result from the difference in volume expansion or contraction behavior caused by the frequency of the temperature fluctuation during solidification. In order to study the effect of these temperature fluctuations a model of the thermal stress field using ANSYS simulation software was employed. In addition, a NDT-UT system was used to localize and describe the presence of defects caused by thermal or transformation stresses. The results of this study are presented and discussed.
Authors: Zhanfang Wu, Hsiang-Ling Juan, and C. Isaac Garcia
Keywords: Slab defects, NDT, ANSYS, Thermal stresses, Internal crack