Investigating effect of surface preparation treatment on occurrence of stress corrosion of a 316L Austenitic Stainless Steel in Magnesium Chloride Solution

tensile stress according to available literature on stainless steels , plays an important role in the occurrence of stress corrosion cracking SCC. The aim of current study is to investigate the effect of surface compression due to various surface treatments such as shot pinning or sand blasting in reduction of tensile stresses as well as its influence on suppressing or postponing SCC. Microhardness results ontained for different austenitic stainless steel specimens after various surface pre treatments revealed that surface hardness was greatly increased dur to shot pinning and sand blast however the bulk hardness remeined unchanged . furthermore, results showed that only a few mono layers at sample surfaces were affected by the surface treatments. stress corrosion experiments were carried and in solutions containing 20,30 and 40wt.% of NaCl at 40 and 90 C. samples were cheched daily to capture the time of crack initiation and also to understand the manner of crack propagation. according to the results samples tested at 40 C did not show any corrosion cracks while samples tested at 90C showed that the existence of compressive residual stresses at the surface as a result of surface treatment had greatly postponed the crack initiation process.

کلیدواژه ها:

Surface treatment on SCC ، shot pinning &sand blasting ، SCC316L ، CL- SCC