Duplex and Carbon Steel in the Petrochemical Industry
Duplex and carbon steel are usually the two most common alloys that are the material of choice in the petrochemical industry. They are called ‘duplex’ as they have approximately equal proportions of ferritic and austenitic phases. This chemical composition gives it better strength, weight saving, greater corrosion resistance and a better price stability.
Unlike similar steels, duplex also displays improved resistance to localised corrosion, particularly pitting, crevice corrosion and stress corrosion cracking. Due to its ferritic qualities, it also shows very good resistance to stress corrosion cracking, as well as good ductility when compared to standard austenitic steels. In some cases, the strength of duplex stainless steel can be up to double that of the most commonly used grades of stainless steel.
In terms of applications, duplex piping products are used for a wide variety of functions such as:
- Transportation of various liquids and gases
- Structural and mechanical components of processing plants
- Heat exchangers
- Cooling pipes
