Hot rolling effects on residual stress of structural materials of austenitic A-2 non standard steel by using neutron diffraction technique

Measurement of hydrostatic residual stress distribution in hot rolled Austenitic steels (A-2) have been carried out. Rolling process of structural construction component materials is recommended because it offers better load ratio strength for the application of the materials as vital materials that need special requirements, where safety factor becomes the primary priority. Four specimens were prepared in this study, i.e. one specimen (unrolled) as a reference called A2D0n, three specimens are the rolled ones called A2D2n, A2D3n and A2D5n, with thickness reduction of 71%, 81% and 87% respectively. The measurement shows that the reduction of 71% in hot rolling generates lattice strain and hydrostatic residual stress of about 0.25% and 9.7 MPa respectively, while 0,27% strain and 10.2 MPa stress is resulted from 81 % reduction. The strain and stress revert back to 0.23% and 8.3 MPa after hot rolling at 87% reduction. It can be concluded that the rise of straining in A-2 non standard steel may be caused by the shifting of crystal plane due to rolling mechanism, which increases the mechanical strength by strain hardening of the material. The residual stress distribution in structural material of austenitic-2 is tensile stress. (author)