Effect of MnS inclusion dissolution on carbon steel stress corrosion cracking in fuel-grade ethanol

摘要

The intrinsic dissolution rate of Manganese sulfide (MnS) was measured in water with hydrochloric acid and in fuel-grade ethanol (FGE) with acetic acid and hydrochloric acid using static disk system. The intrinsic dissolution rate of MnS is used to evaluate conditions inside the intergranular stress corrosion cracks (SCC) by studying partially dissolved MnS inclusions on intergranular SCC fracture surfaces of failed carbon steel piping handling FGE. The penetration rate of MnS inclusion dissolution front was measured to vary from 11 mu m/year up to 127 mu m/year inside the cracks. According to the results the conditions inside intergranular SCC crack are not acidified. (C) 2015 Elsevier Ltd. All rights reserved.