(p696) High-performance hybrid welding process with integrated preheating of high-strength fine-grained steels

摘要

Within these investigations, a combined welding process consisting of inductive preheating and a single layerGMA-laser hybrid welding process was developed. High-strength fine-grained steels with grades of 460 up to690 N/mm? in a thickness range from 10 to 20 mm were welded in one operation. By means of inductivepreheating, the cooling period as well as the microstructure and mechanical properties were influenced.Furthermore, cold and hot cracking of the weld metal and the HAZ was affected. The weld qualities were classifiedusing visual inspection, x-ray inspection and metallographic analyses of cross-sections according to ISO 13919and ISO 12932. The welded seams reached the normative regulations of quality level B. The effect of variouspreheating temperatures on the cooling down periods and the mechanical properties were shown usingtemperature measurements, hardness measurements, as well as tensile tests and Charpy impact tests. For adeeper process understanding, the experimental investigations were accompanied by numerical simulations of theinductive preheating and the GMA-laser hybrid welding. A good agreement between measurements andcalculations could be reached.