Research On The Manufacturing Of A Type Of High-strength Bolt

High-strength bolts are widely used on jet engines because of their advantages, such as good connection rigidity, heat and pressure endurance, and assembly convenience. In recent,years it has drawn higher requirements for the fasteners to be more reliable and serve longer. Heads of the high-strength bolts intended for jet engines must be forged to shape. For the bolts made of GH4169(Inco718), the raw materials GH4169 has high deformation resistance and its structure and performance is highly dependent on the heat processing for the one hand, and for the other hand bolts made of the very alloy possess relatively high fatigue resistance and stress endurance. Thus research on the processing of the bolts made of GH4169 is of great significance.Based on the features of the double-hexagonal head bolts, the chemical composition, phase composition and grain morphology of GH4169 were theoretically analyzed. Deform-3D was used to numerically simulate the forging processing. On the base of the simulated result, processing plan was finally made, with optimized mold structure and elongated mold service life.Parameters of heat treatment on parts made of GH4169 were analyzed, and the influences on the performances of the parts yielded form the position of heat treatment in the processing flow were determined.To meet the procurement requirement, parts were rolled to shape the threads and the head-to-shank fillets, and the tensile strength, fatigue strength and stress rupture resistance were improved. Deform-3D was adopted to numerically simulate the thread rolling.Results of the testings, such as room temperature tensile and high temperature tensile, on the final parts showed that the products were of excellent performances.