Investigations on Effects of Forming Parameters on Product Dimensions in Cold Drawing of AISI-316 Stainless Steel Rods

Abstract

Cold drawing is a commonly used metal forming technique carried out by pulling a billet through a die cavity to obtain desired dimensions. Ideally, the cross-sectional area of the drawn product should be equal to that of the die at its exit; however, the former one is always larger after drawing, in practice. In this study, cold drawing of an AISI-316 stainless steel rod is investigated through finite element analysis. The difference between the product radius and the die radius is denoted by ∆R. A series of simulations using combinations of various forming parameters, including semi-die angle, bearing ratio, reduction ratio, drawing speed and friction coefficient, are conducted to find out the dominant factors of ∆R. It is found that ∆R is mainly affected by semi-die angle, reduction ratio and friction. An empirical formula for ∆R, including various parameters, is established according to the simulation results and verified by drawing experiments as well. Using this empirical formula, the product dimensions can be predicted in advance and proper forming parameters can be chosen to decrease ∆R and improve the product quality.

Keywords

• cold drawing
• stainless steel rod
• forming parameters
• product dimensions
• finite element analysis