The aim of the present work is to investigate the influence of the initial microstructure on the achievable microstructure during hot rolling of nickelbase-superalloy Alloy 718 (INCONEL718). Two materials, a forged slab with grain size ASTM 4-6, and a partial cogged slab, with grain size ASTM 4,5 8 and remaining casting structure up to 36%, were examined. The rolling process was simulated and analysed using the finite element program DEFORM™, for the simulation of microstructure, models from literature were used. For validation of simulated results, annealing tests at 950°C, 1000°C, 1015°C, 1020°C, 1050°C, 1100°C und 1150°C, as well as forming experiments with doublecones were performed. The deformation tests were conducted as multistep tests, with final deformation degrees of 0,3 and 0,4. The deformation rates were 2s-1, 1s-1, 0,1s-1, at temperatures of 980°C, 1000°C, 1030°C, 1050°C, und 1100°C. The samples were examined regarding recrystallised fraction and grain sizes. The results were used to identify possible process windows for the hot rolling process.