The developments of inductive preheating and GMA-laser hybrid welding in one process lead to high quality welded joints for the high strength fine-grained steel grades S700, X70 and S690 in a material thickness range from 10 to 15 mm. The potential use of this technology can be demonstrated. The effect of various preheating temperatures on the cooling down periods and the mechanical properties are shown using temperature measurements, as well as tensile, notched-bar impact and hardness tests. For a deeper process understanding, the testing results have been used to validate numerical models which connect the simulation of induction preheating and GMA-laser-hybrid welding in one holistic FE-model.