1Mechanical Engineering and Materials Science Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA 2
School of Materials Science and Engineering, Northeastern University, China 3
National Engineering and Research Center of Continuous Casting Technology, Central Iron & Steel Research Institute, China
Isaac Garcia C, Ferrous Physical Metallurgy Group, Mechanical Engineering and Materials Science Department,
University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
Received: June 23, 2018; Published: August 01, 2018
Nondestructive testing (NDT) and signal processing were used to detect, locate and define surface and internal defects in
unidirectionally solidified laboratory ingots. These defects included cracks, voids, coarse non-metallic inclusions and heavy 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 continuously cast steels. The high thermal stresses result from the difference expansion or contraction behavior caused
by the frequency of the temperature fluctuation during solidification. In order to study the effect of these temperature fluctuations
to the defects, a specially designed copper chill mold that simulates the solidification rate of continuously cast slabs was designed.
In addition, a NDT-UT system was applied to localize and describe the presence of defects caused by thermal or transformation
stresses. Furthermore, the signal processing analysis was used to characterize the changes in microstructure and hardness. The
results of those studies are presented and discussed.