Parameters of Necking Onset during Deformation of Chromium–Nickel Steel Irradiated by Neutrons

Abstract

Mechanical tests of 12Cr18Ni10Ti (AISI 321 analogue: 10 Ni, 0.12 C, 0.5 Ti, 18 Cr, <2 Mn, and Fe for balance) commercial stainless steel accompanied by “Digital marker extensometry”, and magnetometry, have been carried out after neutron irradiation to a maximum fluence of 1 × 10²³ n/m² (E > 1 MeV). The plastic instability stress and strain of the necking onset have been estimated. The results of three independent methods are in good agreement. The true local strain at the beginning of the necking process in the 12Cr18Ni10Ti steel has been established to decrease with increasing fluence, whereas the true plastic instability stress remains almost the same.