Stress Corrosion Cracking of an Austenitic Stainless Steel in Nitrite-Containing Chloride Solutions
This article describes the susceptibility of 316L stainless steel to stress corrosion cracking (SCC) in a nitrite-containing chloride solution. Slow strain rate testing (SSRT) in 30 wt. % MgCl2 solution established SCC susceptibility, as evidenced by post-SSRT fractography. Addition of nitrite to the chloride solution, which is reported to have inhibitive influence on corrosion of stainless steels, was found to increase SCC susceptibility. The susceptibility was also found to increase with nitrite concentration. This behaviour is explained on the basis of the passivation and pitting characteristics of 316L steel in chloride solution.
Effect of induced stress on the corrosion rate of medium carbon steel in saline environment
This study investigated how 0.33% medium carbon steel is affected by induced stress in a saline environment. Three geometries namely U-bend, C-ring and I-shape samples were formed representing varying degrees of stress level induced on the samples. The test specimens were subjected to static loading in saline environment containing 15.0 wt.%, 10.0 wt.% and 3.5 wt.% of sodium chloride (NaCl) for a typical exposure time of 31 days at ambient conditions of temperature and pressure. Weight loss method was used to estimate the corrosion rate in mils per year (mpy). The results of the experiment show that corrosion rate is maximum in samples with the highest stress level and in medium containing highest amount of dissolved chloride ions. The least corrosion rate occurred in samples with the least amount of chloride ions and in a non-stressed condition. It was inferred that the corrosion rate of 0.33%C steels increased with increasing tensile stress and chloride ions content of the medium. 
 
   
 
 Key words: Stress corrosion cracking, medium carbon steel, saline environment, corrosion rate.
General expression for the density effect for the ionization loss of charged particles
The equations for the density-effect correction $\ensuremath{\delta}(X)$ for the ionization loss as given in a previous paper have been extended to the case where $\ensuremath{\delta}({X}_{0})\ensuremath{\equiv}{\ensuremath{\delta}}_{0}g0$. Here ${X}_{0}$ is the lower limit of the range ${X}_{0}lXl{X}_{1}$, where a particularly simple expression for $\ensuremath{\delta}(X)$ applies; $X={log}_{10}(\frac{p}{{m}_{0}c})$, where $p$ is the momentum and ${m}_{0}$ is the mass of the incident particle. The case ${\ensuremath{\delta}}_{0}g0$ applies directly to the calculation of $\ensuremath{\delta}(X)$ for conductors (metals).