Stress corrosion cracking of stainless steels in amine units

The main task of amine units is removing of acid gases such as. Grades with high resistance to chlorideinduced stress corrosion cracking scc duplex stainless steels, austenitic stainless steels with a high nickel content 25%. Amine corrosion is caused by one or more of the following factors. Scc behavior of a grade a106 carbon steel was investigated by slow strain rate test ssrt. Corrosion and stress corrosion cracking initiation of. As indicated in this figure, corrosion in amine plants can be divided into.

Stress corrosion cracking scc of carbon steel equipment in amine units has been experienced in several plants in the petroleum and gas industries. Amine corrosion and amine cracking of api 5l x52 carbon steel in. Api rp 945 r2008, avoiding environmental cracking in amine units, 3rd. Pdf corrosion and stress corrosion cracking initiation of grade. Scc is highly chemically specific in that certain alloys are likely to undergo scc only when exposed to a small number of chemical environments. Amine units are generally used in refineries and petrochemical plants to remove acid gases such as hydrogen sulfide h2s and carbon dioxide c02 from process streams. The corrosive agents are acid gases, oxygen, heat stable salts, amine degradation products, and, in refineries, gas contaminants such as ammonia and hydrogen cyanide. Corrosion in amine gas sweetening plants has been studied from. Stress corrosion cracking scc initiation of carbon and stainless steels in rich and lean mea environment has also been studied by gonzalez et al. Amine cracking is a form of stress corrosion cracking, which is related to alkaline and. Cracking is mainly associated with the weld heat affected zone haz or the welding.

In this research, stress corrosion cracking scc and corrosion behaviour of api. Amine cracking typically occurs on the surface and the cracks are usually radially projected from seton nozzles. This study is investigates cracking and leakage of a 304 type stainless steel plate. Stress corrosion cracking of carbon steels in amine units. Carbon steel and stainless steel are suitable for most applications, with the choice. High concentration of formate in amine solution, and also high level of stress under. Types s31600 and s31254 stainless steel heat exchanger plates have. It can lead to unexpected sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. Their results implies that carbon steel was prone to scc in amine solution. Elastomerinduced crevice corrosion and stress corrosion cracking. Failure analysis of type 304 stainless steel amine exchanger sheets.

The most economical material is carbon steel with the exception of stainless. This explains the stress corrosion and the conditions. The chemical environment that causes scc for a given alloy is often one which is only mildly corrosive to the metal. This study concerns corrosion and stress corrosion cracking scc initiation of type 304 and 316 austenitic stainless steels in activated methyl diethanol amine amdea solution. Three different mechanisms involved in stress corrosion. Corrosion mechanisms are provided for carbon steel exposed to amine solutions and for amine regenerator overhead systems containing aqueous condensate. Survey updates amine stress corrosion cracking data oil. Pdf corrosion and stress corrosion cracking initiation. Reports of stress corrosion cracking scc of carbon steel in amine solutions date back to the early 1950s. Ferritic steels are also resistant to cracking but may corrode. Most often found in stainless steels in heat affected zones. Corrosion and cracking was more sever under the gasket region of the amine exchanger.