Stress Corrosion Cracking of Carbon Steel in Amine Systems

Abstract A task group, T-8-14, was formed by the T-8 Group Committee on Refining Industry Corrosion to conduct a survey into the stress corrosion cracking of existing amine units. The main purpose of the survey was to determine the extent of cracking problems in such units and to look at possible correlations between cracked and non-cracked locations to establish possible cause(s) for cracking. A total of 294 completed survey forms were received and analyzed. Cracking was reported in MEA, DEA, MDEA and DIPA solutions but was most prevalent in MEA units. Cracking occurs in all types of equipment and piping operating at all common temperatures. Cracking has been reported in all typical refinery streams containing FLS, CCL or a combination of the two. The use of corrosion inhibitors, soda ash, caustic, filters or reclaimers has no indicated effect on cracking tendencies. The survey results confirmed that stress relieving is a highly effective means for preventing amine stress corrosion cracking.