Effects of Peening on Stress Corrosion Cracking in Carbon Steel

Author:  D Kirk, P E Render
Source:  Conf Proc: ICSP-7 (pg 167-176)
Doc ID:  1999027
Year of Publication:  1999
Abstract:  
Stress corrosion cracking is an inherent problem commonly found in most carbon steels. This research compares the susceptibility of mild, heat-treatable and surface-treated carbon steels to SCC and investigates the effect that shot peening has on retarding it. U-bend specimens of mild, case-hardened and heat-treated EN8 steels at known tensile stresses were tested in dilute solutions of strong mineral acids. Calibrating the stress applied to the specimens was done using an instrumented strain bolt. This enabled the tensile surface stress on the outer radius of the U-bend specimen to be measured and allowed accurate time-to-crack measurements to be made. Studies showed that material conditions, in terms of hardness, microstructure and heat treatment, greatly affected the susceptibility to SCC. It was also found that shot peening substantially reduced SCC susceptibility. Using U-bend specimens of martensitic, EN8 steel, immersed in 30% sulphuric acid and heated to 67