Theoretical and experimental analysis of roll bending of half ring of gas turbine

Abstract

The article presents an analysis of forming half reinforcement ring housing the gas turbine. The ring is made of INCONEL alloy 617 material, which is based on nickel-chromium-cobalt-molybdenum alloy characterized by high strength and resistance to oxidation at high temperatures as 1100-1200°C. Square bar of dimensions 50x50 roll bending at half ring with a diameter of 1500 mm, an intermediate product is prepared for machining. The forming process is divided into two operation. The first operation is to pre-bending the rod. The second operation is to roll bending to the radius determined by the deflection. The article presents the map of reduced stress of HMH for two operations, obtained from the numerical simulation based on the finite element method. It also presents the load on the tools during the entire process. Physical tests were carried out on the device for roll bending steel profiles DURMA PBH 125. The article sets out the minimum allowances technology needed to complete half of the ring. A comparison of deviations, outside diameter of the ring, was resulting from the spring back in the study of physical and numerical simulations. We also compared the flatness deviation of the ring resulting in the research. The results of theoretical research have confirmed good agreement with physical examinations. The research provided an opportunity to develop technologies forming of half ring on the above machine of bending steel profiles.