Experimental and finite element analysis of residual stresses in cold tube drawing process with a fixed mandrel for AISI 1010 steel tube

Cold tube drawing with a fixed straight mandrel (fixed plug) is one of the major drawing process in tube drawing operations. Although the process has high dimensional accuracy and good surface finish in general, the process parameters have significant effects on part quality. Therefore, an accurate finite element model is extremely important to improve part quality and reduce the cost of the part. In this article, a cold tube drawing with a fixed straight mandrel is studied experimentally and numerically for AISI 1010 steel tube. Two different reduction of areas of 16 and 23% are considered. X-ray diffraction (XRD) method is used to determine hoop residual stresses inside the tube wall at five different orientations. The experimental models are validated successfully with finite element analysis (FEA) by correlations of the compression force vs. the displacement and the residual stress vs. the position. Effect of the drawing parameters on the hoop residual stress is studied by an axisymmetric finite element model. Although the reduction of area strongly affects the residual stress compared to other process parameters, the friction coefficient has minimum effect on residual stresses. This study concludes that the residual stress states inside the tube wall produced by cylindrical and conical plugs are completely different.