Stress Corrosion Cracking of Steel Component Exposed in Simulated Seawater

Abstract

Stress corrosion cracking (SCC) is the fracture of susceptible material under sufficient tensile stress and exposed to the corrosive environment. A reliable experimental setup for SCC is required to determine the material performance in artificial environment before being deployed in actual situation. Creep machine was modified to establish a constant load SCC test setup for round and plate specimens. The furnace was removed and replaced by the designed machine parts including test solution chamber, grips, leakage prevention mechanism and other related components. The reliability of the established SCC test setup was evaluated by comparing the elongation and hardness of specimen after SCC in corrosive environment and tensile test under constant load at ambient temperature without any corrosive liquid. Both experiments were conducted with a fixed time period before the elongation and hardness of each specimen were recorded. The load of 60 kg and 30 kg for round and plate specimens, respectively were applied in the corrosive environment of 3.5% NaCl simulated seawater for the SCC test. It was found that SCC caused the specimen to have more elongation and lower the hardness compared to the specimen tested in air without any liquid. This is due to the presence of the corrosive environment containing the chloride ions that caused corrosion on the specimen under stress. Consequently, the specimens that have undergone the SCC test suffered more deformation compared to those tested in air. It can also be concluded that the experimental setup for the SCC test was successfully designed, fabricated and validated.