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 graphitiazation
- Type 3: active corrosion by carbon and oxygen
The report also outlined the progress of metal dusting monitoring techniques, i.e., coupon and acoustic monitoring are the most practical and promising monitoring practices.
The industrial practices to mitigate metal dusting are discussed in this report as well. It is commonly believed that not a single alloy is absolutely immune to the metal dusting. However, material selection, proper coating and optimum operation envelop are the key to mitigate the metal dusting risk. Various of industrial experience and failure cases provided the valuable information for future design, operation and inspection to mitigate such risks.
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