Corrosion Case

Corrosion Failure Investigation-Case Study

The presentation of Wayne D. Niemeyer ( 2nd case starting from 17:00)  has demonstrated the importance of understanding of process and production chemistry for the corrosion root cause analysis(RCA). This principle is prompted by ASTM G161  Standard Guide for Corrosion-Related Failure Analysis The most important observation from this case is to determine the chemistry of fluid not only  from  normal production, but also from upset stage. This could be a challenge in certain plant/process due to cost-saving practice by minimising “unnecessary” monitoring. RCA may run into the dead end without weekly lubricant sample been analysed. The final conclusion was leaking of…
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Metal Dusting: recent progress and industrial experience

The metal dusting is one of major failure mechanisms of equipment in producing process of hydrogen, ammonia, and syngas, as well as methanol reforming.  Although it has been recognized for the decades, there are still controversies in its mechanism.  With the recent development in metal dusting research, industries are having better understanding and may develop practical approaches to combat this type of failure. In this report, the recent research of metal dusting mechanism is summarized. It is reasonable to group these mechanisms in 3 types per Szakálos’ proposal: Type 1: decomposition of metastable carbides (e.g. cementite), Type 2: decomposition of…
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Corrosion under Polluted Atmospheric Environment

The atmospheric corrosion is probably the most common forms corrosion in daily life. The corrosion rate of steel is very much influenced by atmospheric environment. Under heavily polluted atmospheric environment, the corrosion is much severer than it in unpolluted environment. The factors of significance in atmospheric corrosion are time of wetness, rain, fog, dew are all contributing to the wetness. Temperature, particulate matters, wind direction, salt deposition and presence of pollutants etc are of great importance in atmospheric corrosion process. In an urban area and heavily industrial polluted zone, it has been proven both gaseous and solid forms of pollutants…
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Guadalajara Sewer Explosion by Stray Current Corrosion

Stray Current Corrosion of Ductile Iron Pipe (DIP) Near Steel Pipeline The most notorious incidents is catastrophe of  Guadalajara Sewer Explosion.The sewer network in Guadalajara, Mexico was exploded in April 1992. The official toll was: 206 dead, 500 to 600 missing, 1 800 injured and, in all, 4 500 disaster victims. Associations estimate that the catastrophe actually caused at least 1000 deaths. The catastrophe caused damage worth 200 billion pesos (76 million Euros 2006), which included ~13 km of streets, 1500 houses, 1224 buildings and 637 vehicles. The scientific investigation found the stray current corrosion is the blame. According to…
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Corrosion in Downstream of Chemical Injection

In practice, the corrosion could be the consequence of multiple factors and corrosion mechanisms. Here is the corrosion case in the well head of natural gas wells. The corrosion was identified due to gas water leakage at area B. The further repair found that “A”, “B”, “C” and “D” are severely damaged. The worst metal loss area is “B” , which may experience up to 1 mm/yr. Further failure mechanism analysis confirmed: 1) Flow assisted corrosion caused by high flow rate, the primary deterioration mechanism is chemical injection, which is termed as mixing point corrosion in downstream refinery 2)      Corrosvitiy…
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