Effect Of Process Parameters On The Rolling Deformation Of Wheels And Analysis Of Web Thinning

The hot forming process of the railway wheel not only determines the shape and size of the wheel product,but also has an important impact on its service life and safety performance.Wheel rolling is the most complicated step in the process of wheel hot forming,and the rolling process determines the dimensional accuracy and the forming quality of wheels.In this paper,the metal migration volume in the wheel rolling process was calculated to analyze the influence factors of web thinning during wheel rolling.The process of wheel rolling was simulated by the finite element software Super Form,and the deformation characteristics of the wheel,dimension variations,the distribution of stress and strain of the wheel were analyzed.The influence of rolling process parameters were also explored.The results enriched the theory of wheel rolling and provided theoretical basis and technical support for the optimization of wheel rolling process.The main contents and conclusions are as follows:(1)The metal migration volume of the rim during the rolling process was calculated with analytical method and the influence factor on the web thinning was examined.The results show that: The web thinning during wheel rolling process is almost related to the inner and outer diameters of the rim and the feed amount per pass.It is possible to suppress the web thinning,by the reasonable controlling of the amount rim expanding and the feed rate in the rolling process.(2)The influence of the feed rate of the back roll on the rolling deformation during the rolling process was studied.The results show that: The smaller the feed rate of the back roll,the greater the effective strain of the wheel blank tread and the deformation zone between the web roll.Additionally,the deformation penetration under the tread surface become faster,and the thinning amount in the non-rolled region of the web decrease with the smaller feed rate of the back roll.(3)The numerical simulations of two different degrees filling of the wheel blanks were carried out to study the influence of the rim filling on the deformation in the rolling stage.The results show that: Using the high degree filling wheel blank is beneficial to improve the expansion efficiency of the rim in the rolling process.With a low filling degree of the wheel,the spread of rim in main deformation zone and the deformation of the blank surface is increased in the rolling process,and the deformation of rim center is also increased.(4)The influence of height variation of wheel center in the rolling process was analyzed.The results show that: The shift up of the wheel center is conducive to increase the inner and outer deformation of the rim during the rolling process.The shift down of the wheel center is conducive to the expansion of the rim and the extension of the web length,and it is also beneficial to improving the forming efficiency of the flange and decreasing the web thickness reduction.