The present study describes the possibilities of new experimental and numerical methods to predict the crack susceptibility of steels under continuous casting (CC) conditions. The first method—the In-Situ Material Characterization by Bending (IMC-B) Experiment allows measuring the critical strain values for surface defects upon all the most important process and material parameters. The IMC-B experiment uses solidified samples obtained directly from the melt and is based on the 3-point bending test. Strains are calculated directly after the experiment has used a simulation in Abaqus. The risk of surface cracks is shown by using the new numerical tool, so-called defect indices implemented in IDS. In the framework of practical series, a crack susceptibility of the commercial Nb-microalloyed steel is investigated after the subsequent cooling to the test temperature. Samples cast at two different cooling conditions show another distribution of surface defects and critical strain value.