Precision Forging Approach for Metal Iron Seat of Railway Track Based on Reversed Bending in Preforming Design

To address the challenges of precision forging for iron seats on railway track, a refined forging method is proposed, involving multiple preforming processes such as arch‐shape reversed bending, warping angle formation, arched shape flattening, warping angle flattening, and reshaping. The dovetail groove in the middle of the iron seat is supposed as a plate structure. Based on the bending and forming theory of plate structure, a physical model of multistep preforming based on reversed bending is first established to analyze the entire forging process, including reversed bending, flattening, and reshaping. Then, focus is placed on studying the neutral stress layer position after the reversed bending during the flattening process of the central dovetail groove, to ensure forging accuracy. The distribution state of the neutral stress layer during the flattening process of the dovetail groove is simulated via professional simulation software Deform; therefore, the position of the neutral stress layer during flattening is plotted. Results show that the theoretical curvature radius of the stress‐neutral layer during the flattening process of arch‐shaped dovetail groove is 33.07 mm, and the stress‐neutral layer is located at 0.37 of the total thickness of the bent plate near the large arc surface, while the simulated neutral layer is at 0.36 of the total thickness of the bent plate near the large arc surface, with an error of only 2.7%. Additionally, at a simulation temperature of 950–1000 °C, the theoretical length of iron seat bottom after flattening is 122.34 mm; meanwhile, the length of the simulated neutral layer at the bottom of the dovetail groove is 122.32 mm, indicating good agreement with its theoretical length. The reversed bending preforming design method not only solves the technical challenges of precision forging for iron seats, but also provides an important reference for the precision forging of other complex structural components.