Analysis of residual stress in steel bar processed by cold drawing and straightening

西田 智*; 西野 創一郎*; 関根 雅彦*; 岡 勇希*; Harjo, S.; 川崎 卓郎; 鈴木 裕士; 森井 幸生*; 石井 慶信*

Materials Transactions, 62(5), p.667 - 674, 2021/05

https://doi.org/10.2320/matertrans.P-M2021808

In this study, we used neutron diffraction to analyze in a non-destructive method the distribution of internal residual stress in a free-cutting steel bar processed by cold drawing and straightening. The residual stresses were successfully measured with excellent stress balance. The residual stresses generated by the cold-drawing process were reduced by subsequent straightening, and the distribution of residual stresses by finite element method (FEM) simulation was consistent with the measured values by neutron diffraction. As a result of the FEM analysis, it is assumed that the rod was subjected to strong tensile strains in the axial direction during the drawing process, and the residual stresses were generated when the rod was unloaded. Those residual stresses were presumably reduced by the redistribution of residual stresses in the subsequent straightening process.