Ring compression test for high strength steel at high reduction in height under dry condition

Cold forging of automotive parts in high strength steel causes pressure on the die. The or heavy load reduces a die life and accuracy forged parts, so prediction more accurate helps us to design optimum dimensions process. In this report, precise frictional coefficient was measured by ring compression test predict cold upsetting steel. experimental results indicated μ about 0.19 within height reduction less than 20% under dry condition. However, when exceeds 20%, deviate from calibration curve assumed be constant = 0.19. This means that friction changing during compression. Slight adhesion observed surface, which must directly increase coefficient. modified considering change Using curves, are exactly plotted is drawn 0.25 at 20%. increasing helpful estimate rod upset