cone angle and length of sizing belt of drawing die
and drawing speed on drawing stress and drawing surface accuracy of bearing steel GCr15 (1. 01% C
1. 58% Cr) Φ11 mm rod coil has been analyzed. The optimization process for Φ11 mm rod coil cold drawing to Φ10. 2 mm rod is obtained
i. e. Φ11 mm rod coil (HB193)- isothermal spheroidizing annealing (at 785℃ for 4. 5 h → at 750 °C for 3 h) - cold drawing to 10. 4 mm rodde-stress annealing at 740 ℃ for 4. 5 h- cold drawing to Φ10. 2 mm rod products (HB205) ; the nice surface quality is obtained by using the process measures including with cold speed 35 m/min and drawing oil lubricant.