A parametric study of process parameters in external thread rolling

This paper summarizes the results of a numerical study conducted to analyze the effect of selected process parameters on material flow and thread profile in external thread rolling of large diameter blanks. Based on the previous work where a plane strain model was found to provide a reasonable approximation of the thread rolling process, the effect of varying thread form, friction factor, flow stress, and blank diameter on effective strain and thread height was analyzed using the finite element code DEFORM. The results of the study show that for the range of conditions considered, that blank diameter had little effect on the as-rolled thread while flow stress (K and n), friction factor, and thread form all had significant impact on effective strain at the thread root and crest and the achievable thread height. While the rate of work hardening was found to have an effect on the crest profile, the results indicate that it is not the primary factor responsible for seam formation in rolled threads.