Effect of process parameters on average grain size and microscopic uniformity of the three-roll skew rolling forming of the railway hollow shaft

Sa？etak The average grain size and microstructure uniformity are the key factors determining the mechanical properties of the hollow shaft. In order to obtain a fine and uniform microstructure, a finite element model of threeroll skew rolling hollow shaft for the coupling of heat, force and microstructure was established. The influence of process parameters on the average grain size and microstructure uniformity of the rolled product was analyzed by using the single factor research method. The results show that the grain size is remarkably refined and the distribution is relatively uniform. The optimum rolling temperature is 1 050 °C; the optimum feed angle is 9 °; the optimum roll rotate speed is 90 rad/min