Research on the Vibration Aging Parameters for Reducing Residual Stress of 50AT Pointed Rail Quenching

Research purposes: In order to reduce the residual stress of 50AT rail after quenching, the finite element analysis model of turnout linear rail was established. The residual stress distribution after quenching was simulated by Deform software, and the vibration aging parameters were obtained by combining the modal response of the rail. Through the blind hole stress measurement evaluation method, the effect of modal aging parameters and enterprise aging parameters on eliminating residual stress after vibration aging of pointed rail was compared and analyzed. Finally, the vibration aging parameters suitable for reducing the residual stress of 50AT pointed rail are obtained. Research conclusions:(1) After the intermediate frequency induction hardening of the pointed rail head is completed, the residual compressive stress distributes in the pointed rail head and waist, and the residual tensile stress distributes in the rail bottom. (2) Based on the characteristics of residual stress concentration, warping and deformation in the middle of the rail bottom after quenching, and the modal mode of the rail, the vibration aging parameters such as the position of support point, the position of excitation point and the frequency of excitation are obtained. (3) Using the aging parameters obtained in this paper, the average elimination ratio of residual stress is 46.6%. The average elimination ratio of residual stress is 28.8% according to the aging rule of the enterprise. The average elimination rate of residual stress under the aging parameters is 1.6 times of the existing aging parameters of the enterprise, and the aging time is only 1/4 of the enterprise aging time, which can significantly improve the production efficiency. (4) The parameters obtained in this paper can be used to guide the reduction of residual stress of 50AT rail after induction quenching. © 2019, Editorial Department of Journal of Railway Engineering Society. All right reserved.