Abstract
The equilibrium phases existing in ZG1Cr10NiAlMoVNbN heat-resistant steel from 200 to 1600°C and equilibrium solidification process were calculated using Thermo-Calc software. The microstructures of three kinds of the test steels were investigated by SEM, also the impact properties were investigated. Results show that the equilibrium phases of the tested steel containing 0·1%Al was single γ at 1050°C; the equilibrium phases of the tested steel containing 0·91%Al were γ+δ; and the equilibrium phases of the tested steel containing 3·67%Al was single δ, the simulation results agreed well with experimental results. Meanwhile, the impact energy reduced significantly with the increase of Aluminium content, the fracture mechanism changed from the dimple fracture to cleavage fracture.