Failures due to stress corrosion cracking (SCC) are often very rapid, violent and result in downtime, lost production and high maintenance costs.
Due to recent changes in environmental regulations, many high pressure installations, previously enjoying base load operation, are now exposed to transient load, stop start and more than often even peaking operation. This operational status typically sees load for only a few short hours a day. The change in production demand has placed a huge stresses on metals of construction and upon the chemistry compliance.
The chemistries simply have not kept pace with the changes in production and expectations from the same. In most high pressure boilers, a pit on the virgin metal surface is the initiator for inter-granular cracking. The crack propagates from the pit. This is the foundation for SCC.
SCC is the thus explained in a very simple manner as being the result of a combination of three factors – a susceptible material, exposure to a corrosive environment, and tensile stresses above a threshold. Accordingly, if you eliminate any one of these factors SCC initiation becomes impossible.
Frequent unplanned failures and outages have an undesirable impact on plant availability and reliability. The conventional approach to controlling the problem has been to develop new alloys that are more resistant to SCC. This is a costly proposition and can require a massive investment to achieve marginal success.
Anodamine has been shown to slow/eliminate SCC related failures by its unique action at isolation of the anode from the corrosive environment. Since Anodamine is uniquely able to penetrate the oxides and reach the virgin base metal, hydrophobic isolation of the virgin metal will ultimately prevent corrosive attach of the metal and eliminate the threat of pitting as a source for propagation of SCC.
“Anodamine is an effective corrosion inhibitor of crevice corrosion of both mild steel and ferritic stainless steels in sodium chloride solutions, provided that it is present in a sufficiently high concentration” (4). If you prevent the pit, you prevent the crack.
Information on Anodamine and its protection against SCC can be found in the following references: