Experimental and numerical investigation of the effects of deep cold rolling on the bending fatigue tolerance of C38500 brass alloy

This paper investigates the effects of deep cold rolling (DCR) treatment on the fatigue life of C38500 brass alloy. Low cycle fatigue (LCF) and high cycle fatigue (HCF) tests were conducted according to Moore rotary bending instrument. The terms LCF and HCF are used here beyond the typical definitions in the literature and are used in this paper to distinguish between the two loading conditions. The DCR treatment was done for various rolling depths of 50, 75, 100, 125, and 150 mu m and passes number to find the most effective conditions. The results showed that the rolling depth of 75 mu m led to most improvement of the fatigue life near 20 and 302% for HCF and LCF regimes, respectively. Furthermore, DCR treatment was performed for the second pass which improved more the fatigue life by about 351 and 45% for LCF and HCF, respectively. Moreover, the effects of DCR parameters such as rolling depth, feed rate, number of passes, the ball diameter, and friction on distribution of residual stresses were evaluated numerically using ABAQUS commercial software. At the end, the finite element (FE) results were correlated with microscopic examinations and experimental findings.