Research on Forming Quality of GH4169 Superalloy Multi-Step Hollow Turbine Shaft by Three-roll Skew Rolling

Abstract

Abstract: This paper innovatively proposes a three-roll skew rolling process for flexible forming of hollow turbine shaft, which solves the problems of long manufacturing process and low material utilization of hollow turbine shaft, the core component of aeroengine. Simufact.Forming 14.0 (SF) numerical simulation software was used to establish the finite element model of two-pass three-roll skew rolling of the GH4169 superalloy turbine shaft. The effects of process parameters on the outer diameter error, roundness error and wall thickness uniformity of the rolled piece were investigated by single factor experiments. A five-factor three-level orthogonal test was designed to explore the optimum process parameters by ' comprehensive scoring method'. The results show that the optimal process parameters are that the first pass roll rotating speed is 40 rad/min, the first pass axial speed is 15 mm/s, the second pass roll rotating speed is 50 rad/min, the second pass axial speed is 25 mm/s, and the billet preheating temperature is 1000ºC. The axial velocity of the second pass has the greatest influence on the test results, while the rotational speed of the second pass has the least influence. Under the optimal parameter combination simulation experiment, the outer diameter error, outer roundness error and wall thickness standard deviation are 0.151 mm, 0.121 mm and 0.034 mm, respectively, which are better than the results in the orthogonal test table. The research results provide a theoretical basis for realizing flexible, economical and high-quality forming of hollow turbine shaft by three-roll skew rolling.