One possibility for the off‐line training of quality prediction modules in continuous casting is the performance of experiments with samples simulating conditions close to the process. An important point is the surface quality. In the last decade, a new testing setup has been developed called the in situ material characterization by bending (IMC‐B) test. This test represents an experimental method, combining solidification, cooling, and deformation in one sequence. It allows the prediction of surface crack formation with respect to the testing conditions. Varying testing parameters enable the determination of the impact of different factors that lead to crack formation during deformation of a casted sample in a hot bending test. The output comprises quantification parameters for damage evaluation, by defining a critical strain for crack formation. Herein, the crack sensitivity for a low carbon construction steel at the bending temperatures of 700–1100 °C is determined. The most critical temperature range is found to be 850–1000 °C.